IPS Hong Kong Chapter



GOOD NEWS!! our IPS Hong Kong Chapter has been awarded the 2014 Largest Membership Increase, 2013 Most Improved Chapter Award by the IEEE Photonics Society (IPS). We were also awarded the IPS Chapter of the Year Award in 2009, 2010 and 2011.  


Committee Members (2018):


Prof. Kevin K TSIA

Vice Chairman:

Prof. Changyuan YU


Prof. Lidai WANG


Prof. Renjie Zhou

Past Chairman:

Prof. Nelson S C CHAN

Other Members

Prof. Calvin C K CHAN

Prof. Alan Pak Tao LAU

Prof. Chao LU

Prof. Andrew W O POON

Prof. Edwin Y B PUN

Prof. Chester C T SHU

Prof. Hwa Yaw TAM

Prof. Hon Ki TSANG

Prof. Alex P K WAI

Prof. Kenneth K Y WONG


[Activities] [Seminars] [Photonics (HK) Postgraduate Student Seminar Series] [Conference Listings] [Job Listing] [Useful Links]




Dec 6, 2014

The Fifteenth IEEE Hong Kong Photonics Society Postgraduate Conference, The Hong Kong University of Science and Technology.

Dec 7, 2013

The Fourteenth IEEE Hong Kong Photonics Society Postgraduate Conference, City University of Hong Kong.

Dec 8, 2012

The Thirteenth IEEE Hong Kong Photonics Society Postgraduate Conference, The Hong Kong Polytechnic University.

Dec 9, 2011

The Twelfth IEEE Hong Kong Photonics Society Postgraduate Conference, The Chinese University of Hong Kong. <Photos>

Nov. 27, 2010

The Eleventh IEEE Hong Kong LEOS Postgraduate Conference, The University of Hong Kong.

Nov. 28, 2009

The Tenth IEEE Hong Kong LEOS Postgraduate Conference, The Hong Kong University of Science and Technology. <Advanced Programme> <Photos>

Jul. 13-17, 2009

The 14th OptoElectronics and Communications Conference (OECC 2009), Hong Kong

May 7-8, 2009

Symposium on Sustainability Driven Innovative Technologies (Green Automotive, Green Computing & Packaging, Green Display & Lighting Technologies), Physical Society of Hong Kong.

Nov. 29, 2008

The Ninth IEEE Hong Kong LEOS Postgraduate Conference, City University of Hong Kong. <Photos>

Dec. 8, 2007

The Eighth IEEE Hong Kong LEOS Postgraduate Conference , The Hong Kong Polytechnic University. <Photos>

Oct. 22, 2007

Visit to Bookham in Shenzhen

Jun. 11-13, 2007

International Symposium on Next-Generation Lightwave Communications, The Chinese University of Hong Kong.

Dec 9, 2006

The Seventh IEEE Hong Kong LEOS Postgraduate Conference , The Chinese University of Hong Kong.

Feb. 9, 2006

CityU-NICT Joint Forum on Photonics for Next Generation of Information and Communications Technology, City University of Hong Kong

Dec. 3, 2005

The Sixth IEEE Hong Kong LEOS Postgraduate Conference , The University of Hong Kong.

Oct. 29, 2005

Workshop on Frontiers in Nanophotonics, The Chinese University of Hong Kong

Nov. 27, 2004

Singapore-Hongkong Lightwave Workshop on Next Generation Optical Communication Technologies, The Chinese University of Hong Kong.

Nov. 27, 2004

The Fifth IEEE Hong Kong LEOS Postgraduate Conference , The Hong Kong University of Science and Technology.

May 28-29, 2004

Photonics Packaging Workshop, The Chinese University of Hong Kong.

Oct 18, 2003


The Fourth IEEE Hong Kong AP/MTT/LEOS Postgraduate Conference , City University of Hong Kong.

Sept 28,2002


The Third IEEE Hong Kong AP/MTT/LEOS Postgraduate Conference , The Polytechnic University of Hong Kong.

Sept 29,2001


The Second IEEE Hong Kong AP/MTT/LEOS Postgraduate Conference, The Chinese University of Hong Kong. [Photo]


Jul 10, 2015

Switching Technologies For Spatially And Spectrally Flexible Optical Networks, Prof. Dan M. MAROM (Hebrew University, Israel) [IEEE Photonics Society Distinguished Lecture]

Feb 16, 2015

Bright solitons from defocusing nonlinearities, Prof. Boris A. MALOMED (Tel Aviv University, Israel)

Jan 9, 2015

Nanomechanical Tuning Of Electron States Across Nano-Scale Air Gaps & Optical Probing And Logging Of Glacier Ice, Ms Wing CHAN, (University of Minnesota, USA)

Dec 1, 2014

Extreme Imaging and Beyond, Prof. Keisuke GODA (University of Tokyo, Japan) [IEEE Distinguished Lecture]

Sept 18, 2014

Copying the Human Eye for Better Digital Cameras, Dr. Timothy D. DRYSDALE (University of Glasgow, Scotland)

Aug 19, 2014

Silicon and Indium Phosphide Photonic Integrated Circuits for Optical Communication Applications, Dr. Shaoqi FENG (University of California, Davis, USA)

Aug 11, 2014

Metal-Free Flat Lens Using Negative Refraction by Nonlinear Four-wave Mixing, Prof. Wenjie WAN (Shanghai Jiao Tong University, China and University of Michigan-SJTU Joint Institute, China)

June 19, 2014

Photonics Enables A Microscope In A Needle For Imaging Deep In Tissues, Prof. David D. SAMPSON (The University of Western Australia, Australia)

May 19, 2014

On-chip double zero index platform for planar device applications in telecom regime, Dr. Shota KITA, (Harvard University, USA)

Apr 16, 2014

Seeing Hidden Colours in the Human Body with Diffuse Optics and Acousto-optic, Dr. Terence LEUNG (University College London, UK)

Apr 4, 2014

Casimir Optomechanics: An All-integrated Approach of Probing Virtual Photon, Dr. Pui-Chuen HUI (Havard University, USA)

Feb 27, 2014

Integrated Photonics at the Micro- and Nano-scale, Dr. Joyce POON, (University of Toronto, Canada)

Feb 26, 2014

Integrated Photonics at the Micro- and Nano-scale, Dr. Joyce POON, (University of Toronto, Canada)

July 2, 2013

Microring Lasers And Resonators: Achievements And Future Challenges, Dr. Marc SOREL (University of Glasgow, UK)

June 25, 2013

Recent Advances in Space-Division Multiplexed Transmissions, Dr. Ezra Ip (NEC Labs America, USA)

June 25, 2013

Integrated Optoelectronic Technologies at Glasgow University, Dr. Marc SOREL (University of Glasgow, UK)

June 21, 2013

MIMO Channel for Multimode Fiber: Channel Model and Signal Processing, Dr. Ricky K.P. HO (Silicon Image, Wireless Division, Sunnyvale, California, U.S.A.)

May 23, 2013

Topographic Optical Fibers : A New Degree of Freedom in Nonlinear Optics, Dr. Arnaud MUSSOT (University of Lille I Villeneuve dAscq, France)

May 22, 2013

Optical Vortices and Their Novel Applications, Prof. Larry X.-C. YUAN (Institute of Modern Optics of Nankai University, PRC)

April 25, 2013

Optical Coherence Tomography in the University of Kent, Professor Adrian PODOLEANU, (University of Kent, Canterbury, UK)

Dec 18, 2012

Silicon Photonics without Compromise: Linear, Nonlinear and Quantum Applications, Prof. Shayan MOOKHERJEA (University of California, San Diego, USA)

Nov 9, 2012

Integrated Nano- and Micro- Photonic Technologies for future Networking and Computing Systems, Prof. S. J. Ben YOO, (University of California, Davis, USA)

Sept 4, 2012

Evolution of Telecommunications and The Great Broadband Transformation - Impact of Photonics R and D, Prof. Chinlon LIN (Guest Chair Professor, National Chiao Tung University, Hsinchu, and National Sun Yet-Sen University, Kaohsiung, Taiwan)

July 31, 2012

Polarization in Fiber Optics, Prof. Lianshan YAN (Southwest Jiaotong University, PRC) [IEEE PHOTONICS SOCIETY DISTINGUISHED LECTURE]

July 30, 2012

All-optical signal processing in polarization-division-multiplexing systems, Prof. Lianshan YAN (Southwest Jiaotong University, PRC)

Mar 8, 2012

Tight Focusing of Light Beams With Polarization and /or Phase Modulation, Prof Jixiong PU (Huaqiao University, Fujian, PRC)

Jan 11, 2012

Analysis and Selection Of High-Speed Network Services For Scientific Data Movement, Prof. Malathi VEERARAGHAVAN (University of Virginia, USA)

Dec 15, 2011

Broadband Chromium-Doped Fiber Amplifiers for Next-Generation Optical Communication Systems, Prof. Wood-Hi CHENG (National Sun Yat-Sen University Kaohsiung , Taiwan) [IEEE PHOTONICS SOCIETY DISTINGUISHED LECTURE]

Dec 12, 2011

Research Activities in EEE UNNC and PhD Scholarships in UNNC, Prof. Yaping ZHANG (University of Nottingham

Ningbo, China)

Dec 12, 2011

Fiber Optical Parametric Amplifiers for Optical Communication, Prof. Michel E. MARHIC (Swansea University, Wales, UK)

Oct 20, 2011

Soliton Management in Periodic Systems, Prof. Boris A. MALOMED (Tel Aviv University)

July 25, 2011

Tailoring Ultrashort Laser Interactions for Moulding 3D Photonic and Optofluidic Microsystems, Prof. Peter HERMAN (University of Toronto, Canada)

July 15, 2011

Recent Advances in Optical Communications Research, Dr. Xiang LIU (Bell Labs, Alcatel-Lucent, USA)

July 8, 2011

Scaling Optical Packet Switches to Large Number of Ports, Prof. H. J. S. DORREN (Eindhoven University of Technology, the Netherlands)

May 13, 2011

In Vivo Fluorescence Brain Imaging In Freely Moving Animals, Prof. Mark SCHNITZER (Stanford University, USA)

Feb 8, 2011

Photonic Band Gap Materials: Light Trapping Crystals, Prof. Sajeev JOHN (University of Toronto, Canada) [IEEE PHOTONICS SOCIETY DISTINGUISHED LECTURE]

Jan 28, 2011

Self-Mixing Interferometry:a Universal Yardstick to Measure Almost Everything, Prof. Silvano DONATI (University of Pavia, Italy)

Aug 24, 2010

Interconnecting with Silicon, Dr. Mehdi ASGHARI (Kotura Inc, USA)

July 2, 2010

Materials, Methods, and Applications for Photonics Integration, Mr. Ta-Ming SHIH (MIT, USA)

Apr 30, 2010

Extended-Reach Gigabit Passive Optical Network for Rural Areas, Dr. Alan LEE (The University of Melbourne, Australia)

Apr 30, 2010

Fiber-Wireless Technology, Prof. Christina LIM (The University of Melbourne, Australia)

Apr 28, 2010

Microwave Photonics, Prof. Jianping YAO (University of Ottawa, Canada)

Dec 22, 2009

Physical Layer of Fiber Optical Communication and Sensor Systems, Prof. Changyuan YU (National University of Singapore, Singapore)

Oct 28, 2009

Recent Progress in Distributed Fibre Optics Sensing Towards Centimeter Spatial Resolution, Prof. Luc THVENAZ (Swiss Federal Institute of Technology, Switzerland)

Aug 11, 2009

Physical Layer of Fiber Optical Communication and Sensor Systems, Prof. Changyuan YU (National University of Singapore, Singapore)

Aug 11, 2009

Advances in Nonlinear Fibre Optics, Supercontinuum Generation, Ultrafast Photonics and Applications, Prof. John DUDLEY (University of Franche-Comte, France)


Jul 20, 2009

Advanced Photonic Integration and High-Index-Contrast Circuit , Dr. Sai CHU (Infinera Corporation, USA)

Jul 15, 2009

Presentation I:  Lightwave Technology in Singapore and NTRC (Components, Systems and Networks)

Presentation II:    Simultaneous Implementation of Potohnic OR and AND Logic Gates for CSRZ-OOK Signal

Presentation III:  Optimized Design of Node-and-Link Protecting p-Cycle with Restorability Constraints for Optical Multicast Traffic Protection

(Prof. P. SHUM,  Dr. Songnian FuU  and  Mr. Feng ZHANG
Nanyang Technological University, Singapore)

Jul 6, 2009

New Generation Endomicroscopy Technologies and Translational Nano-biophotonics Imaging, Dr. Xingde LI (Johns Hopkins University, USA)

Jun 26, 2009

Synchronization of Semiconductor Lasers, Prof. Jia-Ming LIU (UCLA, USA)

Jun 18, 2009

Interesting Dynamics of Semiconductor Lasers, Prof. Jia-Ming LIU (UCLA, USA)

May 21, 2009

Nanophotonics Go Green: From Stacked Photonics to Solar Cells, Dr. Weidong ZHOU (University of Texas at Arlington, USA)

Apr 8, 2009

Semiconductor Wafer Bonding Technology for Device Integration, Prof. Paul YU (UCSD, USA)

Feb 11, 2009

VLSI Photonics: Science and Engineering of Micro/Nano-Photonics, Prof. Dr. El-Hang LEE (INHA University, Korea)

Feb 5, 2009

New Trends in Photonics:From Green Photonics to Biophotonics, and Beyond, Mr. Kevin TSIA, (UCLA, USA)

Jan 21, 2009

Development of Fiber Lasers and Their Beam Combination at SIOM, Prof. Qihong LOU (Shanghai Institute of Optics and fine Mechanics, PRC)

Dec 1, 2008

Coherent Dark Resonances: High Resolution Spectroscopy and Applications, Prof Victor N. ZADKOV (M.V.Lomonosov Moscow State University)

Nov 28, 2008

Seminar on Display Technologies, Project: Enhance the Capability of Engineers in the Electronics Industry in Exploiting New Technologies to Develop New Materials, Components and Products? Physical Society of Hong Kong

Nov 25, 2008

Long-wavelength VCSELs and VCSEL Arrays for High-Speed, High-Power and High Sensitivity, Dr Werner HOFMANN (Walter Schottky Institute, Germany)

Nov 21, 2008

Signal Processing in III-V Semiconductors for High Speed Optical Switching, Prof. H.J.S. DORREN (Eindhoven University of Technology, The Netherlands)

Nov 10, 2008

Recent Advances in Parametric Amplification and Processing, Dr. Camille-Sophie BRS (University of California San Diego, USA)

Oct 31, 2008

Integrated Silicon Photonics: Technology and Products, Dr. Mehdi ASGHARI, (Kotura Inc., USA)

Aug 21, 2008

Manipulation of Thermal Radiation Using Nano-photonic Devices, Mr. Wah Tung LAU (Stanford University, USA)

Aug 18, 2008

Manipulation of Thermal Radiation Using Nano-photonic Devices, Mr. Wah Tung LAU (Stanford University, USA)

July 2, 2008.

All-Optical Regeneration - Requirements and Capabilities, Prof. Andrew ELLIS (University College Cork, Ireland)

June 5, 2008

Recent Progress In Silicon Based Micro/Nano Optoelectronic Devices, Prof. Zhiping (James) ZHOU (Peking University, Beijing PRC)

May 27, 2008

Nanowires and Nanolasers: What is the Ultimate Size Limit?, Prof. Cun-Zheng NING (Arizona State University, USA) [LEOS DISTINGUISHED LECTURE]

May 23, 2008

High Power Passive Fiber Components for Fiber Laser and Amplifier, Dr. Kok Wai CHANG (Raydiance-Inc.)

April 29, 2008

THz Science and Technology: an Overview, Prof. Ci-Ling PAN (CUHK, Hong Kong)

April 22, 2008

Soliton Management in Periodic Systems, Prof. Boris A. Malomed (Tel Aviv University, Israel)

April 17, 2008

Gallium Arsenide Electro-Optic Waveguide Devices,  Dr. John HEATON (RFMD (UK) Ltd)

April 16, 2008

Electromagnetic Simulation of Large-Scale Photonic Crystal Problems, Prof. Jian-Ming JIN (University of Illinois at Urbana-Champaign Urbana, USA)

April 11, 2008

Recent Progress in Liquid Crystal Laser and THz Optics, Prof. Ci-Ling PAN (CUHK, Hong Kong)

March 6, 2008

THz Photonics with Liquid-Crystal-Enabled Functionalities, Prof. Ci-Ling PAN (CUHK, Hong Kong)

February 5, 2008

Contemporary Approaches in All-Optical Processing: Exploiting Novel Materials, Structures and Wavelengths, Prof. Roberto MORANDOTTI, (University of Quebec, Canada)

February 4, 2008

An Overview of Recent High Speed Product Development within SHF, Dr. Thomas LEE, (SHF Communication Technology AG, Germany)

January 17, 2008

Energy Harvesting in Silicon Photonic Devices, Mr. Kevin Kin-Man TSIA (UCLA, USA)

December 10, 2007

Coupling Dynamics in Semiconductor Lasers and Applications to Self-Mixing Interferometry and Chaotic Cryptography, Prof. Silvano DONATI (University of Pavia, Italy)

December 4, 2007

The Marriage of Photonics and Communication Theory for 100 Gb/s Long-Haul and Ethernet Fiber-Optic Transmissions, Mr. Alan Pak Tao LAU (Stanford University, USA)

November 30, 2007

The ePIXnet Silicon Photonics Platform and Research at IMEC,, Dr. Pieter DUMON (IMEC ?Ghent University, Belgium)

November 30, 2007

The Marriage of Photonics and Communication Theory for 100 Gb/s Long-Haul and Ethernet Fiber-Optic Transmissions, Mr. Alan Pak Tao LAU (Stanford University, USA)

July 27, 2007

Some Research Activities on Microwave Photonics at COER/ZJU, Prof. Sailing HE (Zhejiang University, PRC)

July 26, 2007

Strongly-confined Si-based optical waveguides and devices, Prof. Sailing HE (Zhejiang University, PRC)

April 19, 2007

Fiber Optical Parametric Amplifiers, Prof. Michel E. MARHIC (University of Wales, UK)

December 7, 2006

Improving the Photonic Integration Density and Functionalities wit Nanostructures Metamaterials, Prof. Sailing HE (Zhejiang University, PRC)

November 13, 2006

Ultrafast Photonic Signal Processing, Prof. Lawrence CHEN (McGill University, Canada)

November 9, 2006

Wavelength Tunable Organic Devices and Nanostructures, Prof. Wallace CHOY (Hong Kong University)

July 31, 2006

Optical Pulse Converter and FWM in Dense Periodical Fibers, Dr. Anhui LIANG (Optvista, Inc, USA)

July 17, 2006

80+ GBit/s ETDM Systems Implementation: An overview of Current Technologies, by Dr. Thomas LEE (SHF Technologies, Germany)

May 20, 2006

Structural Monitoring ? Combining Fibre Optics With Ultrasound, by Prof. Brian CULSHAW

(Unversity of Strathclyde, UK)

May 18, 2006

Remote Near Infra Red Gas Spectroscopy Using Fibre Optic Systems, by Prof. Brian CULSHAW

(Unversity of Strathclyde, UK)

April 13, 2006

Silicon-based Optoeletronics, by Dr. Ansheng LIU (Intel Corp. USA)

April 11, 2006

Silicon-on-Insulator based micro-optical integration platform, by Dr. Lars ZIMMERMANN (Technical University of Berlin, Germany)

December 21, 2005

40 Gb/s Over 10 Gb/s DWDM Long-haul Optically Amplified Transmission, by Prof. Le N. BINH (Monash University, Australia)

December 12, 2005

Silicon-based Planar Lightwave Circuits, by Dr. Daoxin DAI (The Chinese University of Hong Kong)

November 10, 2005

InP Optoelectronics: Design and Fabrication of high performance Fullband

Tunable Lasers and Modulators for Optical Networks, by?Dr. Andy CARTER (Bookham, Inc.)

July 8, 2005

Quantum Well and Quantum Dot Intermixing for Optoelectronic Device Integration, by Prof. Chennupati JAGADISH (Australian National University, Australia)

June 29, 2005

Next Generation PLCs for Optical Communications, by Prof. Yung Jui (Ray) CHEN, (UMBC, USA)

June 28, 2005

Micro-Ring Resonator ?a VLSI Platform for Optics? by Prof. Yung Jui (Ray) CHEN, (UMBC, USA)

November 29, 2004

Advanced Signaling for Optical Fiber Communications, by Dr. Lothar MOELLER (Bell Labs, Lucent Technology, USA)

November 29, 2004

Photonics Research in Shanghai Jiao Tong University , by Prof. Weisheng HU and Prof. Yikai SU (Shanghai Jiao Tong University, PRC)

October 21, 2004

Practical Applications of Optical Parametric Amplifiers in Optical Communication Systems, by Prof. Kenneth KY WONG (HKU)

September 28, 2004

Time-Wavelength Signal Processing and Its Applications to A/D Conversion, Waveform Generation, and Spectroscopy, by Dr. Bahram JALALI, (UCLA, USA)

September 27, 2004

Silicon Photonics Research : Applications Recent Results and Integration Challenges with CMOS processing for High Volume Manufacturing, by Dr. Mario PANICCIA, (Intel Corp., USA)

September 10, 2004

Fiber to the Premises (FTTP): Evolution of the Broadband Networks for Converged Voice, Data and Video , by Prof. Wei Ping HUANG, (McMaster University, Canada)

August 13, 2004

3-Dimensional Nanoimprinting, by Prof. Stella PANG, (University of Michigan, USA)

February 13, 2004

Optoelectronic Packaging for Optical Interconnects, by Prof. Sing LEE (University of California San Diego)

February 10-11, 2004

International Technology Conference: ?004 Technology Drivers for Tomorrow? Photonics and Bio-photonics , organized by Hong Kong Science & Technology Parks (HKSTP)

February 9, 2004


Properties of Planar Lightwave Circuit (PLC) Devices Fabricated by Silica and Polymers, by Dr. Tohru MARUNO (NTT Photonics Laboratories, Japan)

December 12, 2003

Photonic Crystal Fires: a Multi-faceted Superhighway for Light by Prof. Philip RUSSELL (University of Bath, UK)

November 3, 2003

Multi-Wavelength Injection-Locked Laser Diode: A Key Device for Future All-Optical Networks? by Dr. Simon L Y CHAN (The Hong Kong Polytechnic University)

August 7, 2003

Nanoimprinting Technology And Micro Gas Chromatography by Prof. Stella W. PANG (University of Michigan Ann Arbor)

IEEE Photonics Society (HK) Bi-monthly Postgraduate Student Seminar Series

Aug 29, 2014


City University of Hong Kong


​​ EE ​Cloud Computing Centre, ​Room P1615, Floor 1, Academic Building 1



Title: Mode-Locked Fiber Laser with Transverse-Mode Selection Based on a Two-Mode FBG

​​​Speaker: Jiang​li​​ ​​​DONG (City University of Hong Kong)​



In mode-division multiplexed transmission systems, mode conversion is required for generating the higher-order modes from the fundamental modes. Fiber lasers operating at different transverse modes can generate different transverse modes, which are expected to find applications in mode-division multiplexed systems. On the other hand, the cylindrical vector beams (CVB) have attracted a great deal of interest, which find applications in microscopy, material processing, high-resolution metrology, electron acceleretion. Generating CVBs in fiber lasers have many advantages such as compactness, flexibility, and high efficiency. We propose a passively mode-locked fiber laser that incorporates a two-mode fiber Bragg grating (FBG) for transverse-mode selection. By controlling the polarization state of light in the cavity, the laser can provide a continuous-wave output at the LP01 mode, the LP11 mode, or their mix, which correspond to different reflection wavelengths of the FBG. When the laser is mode-locked, it generates picosecond pulses at a fundamental repetition rate of 6.58 MHz for both the LP01 and LP11 modes with a signal-to-noise ratio higher than 56 dB. At a sufficiently high pump power, the laser can generate irregular multiple-pulse trains and harmonic mode-locked pulses.

Title: Tailoring of Saturation in Fiber Optical Parametric Amplifier by SBS-Induced Nonlinear Phase

Speaker: Chaoran HUANG (The Chinese University of Hong Kong)



We have demonstrated the use of stimulated Brillouin scattering (SBS) to control the gain saturation characteristics of fiber optical parametric amplification (FOPA). The saturation can be dynamically deferred or expedited without changing the input FOPA pump and signal parameters. It is observed that the input signal power at saturation can be increased or decreased by up to 6 dB. Experiments are performed to further investigate the role of the SBS-induced nonlinear phase on the power transfer efficiency in the FOPA.


March 7, 2014


The Hong Kong University of Science and Technology



Rm 5508, Lift 25-26, Academic building.




Title: Fluorescence microendoscopic system for imaged-guided holographic photostimulation and laser microsurgery

Speaker: Mr. Anson H. L. TANG, (University of Hong Kong)



Innovations in optical microscopy have successfully been brought, together with the advanced fiber-optic and miniaturized optics technologies, into the realm of minimally invasive in vivo diagnostics with cellular resolution. The main thrust in microendoscopy is to miniaturize the probe in order to ensure flexible maneuver during imaging within the hard-to-reach and complex internal organs, especially brain and small lumens. Equally important is to enable the same endoscopic system for prompt, if not simultaneous, precise intervention on the same field-of-view. Such capability aligns well with the spurred interest in study of neuronal activities using photostimulation or optogenetics, and the pressing needs for high-precision image-guided laser microsurgery.

However, realizing precise spatiotemporal stimulation of neuronal structures in deep brain tissue (>5-6 mm) remains non-trivial. Techniques of generating complex spatiotemporal laser surgical patterns in vivo also remain rather under-explored. To this end, we developed a compact and flexible endoscopic system which can deliver a user-defined holographic illumination patterns with cellular resolution (~1-3 μm) and milliseconds temporal resolution (5.5 ms), based on a spatial light modulator (SLM), through an fiber bundle compatible with a 25.5-gauge needle. The system can simultaneously perform high-resolution fluorescence microscopy through the same fiber bundle a crucial feature maintaining the system compactness and flexibility. We here report the details of the fiber-bundle system design and the preliminary demonstration of the patterned illumination for photostimulation, simultaneously with fluorescence microendoscopy. We also discuss strategies to implement deep-brain holographic photostimulation and image-guided holographic laser microsurgery based on our current system.


Title: Unfolding a design rule for microparticle buffering and dropping in microring-resonator-based add-drop devices

Speaker: Mr. Jiawei WANG, (The Hong Kong University of Science and Technology)



Applying optical surface waves of on-chip integrated optical devices for micro/nano-sized particle and biological cell manipulation has been gaining increasing interest in the research field of optofluidics for lab-on-a-chip applications. In this study, we propose an intuitive and quantitative design rule to determine the microparticle transport processes, including buffering and dropping, on microring-resonator-based add-drop devices at cavity resonances in an integrated optofluidic chip.

The design rule uses the splitting ratio, S, of the optical-field intensity at the microring feedback-arc just after the output-coupling region to that at the drop-waveguide as a figure-of-merit for particle transport to determine between particle buffering (S > 1) and dropping (S < 1). The particle transport, however, becomes probabilistic in the case that S is close to 1. The S factor thus provides a clearer physical criterion for determining the particle transport processes compared to the cavity quality (Q) factor. We experimentally investigate this design rule on four different devices with different design parameters on a silicon nitride-on-silica substrate, and show that the particle transport behaviours of 2.2 μm- and 0.8 μm-sized polystyrene particles are consistent with the S values extracted from the transmission spectra. Our numerical simulations of the four devices suggest that the S values extracted from the simulated transmission spectra are consistent with those extracted from the simulated mode-field intensity distributions. We calculate the optical force field using Maxwell stress tensor and an effective microdisk model to relate the S values to the particle transport processes. We further experimentally demonstrate the viability of the design rule by switching between deterministic particle buffering and probabilistic particle transport processes by switching the polarization modes.


Sept 27, 2013


The Hong Kong Polytechnic University

2:30 p.m. to 4:30p.m.

Rm BC304




Title: Tunable photonic microwave generation using an optically injected semiconductor laser with dual-loop optical feedback

Speaker: Jun-Ping ZHUANG (City University of Hong Kong)



Photonic microwave generation techniques are prompted by the advantages of transmitting microwave signals over optical fibers including low loss, electromagnetic interference immunity, and wavelength division multiplexing capability. In this work, the period-one (P1) nonlinear dynamics of a semiconductor laser subject to both optical injection and optical feedback is investigated for photonic microwave generation. The optical injection first drives the laser into P1 dynamics so that its intensity oscillates at a microwave frequency. A dual-loop optical feedback then stabilizes the fluctuations of the oscillation frequency. A microwave signal with frequency tunable from 13 to 100 GHz is generated by using the P1 dynamics of a laser with relaxation resonance frequency of less than 10 GHz. The dual-loop feedback effectively narrows the microwave linewidth to less than 50 kHz and reduces the phase noise variance by more than 500 times. The P1 dynamics with dual-loop feedback enable stable photonic microwave generation, which is all-optical, widely tunable, and free from microwave devices.


Title: Code aided expectation maximization (CAEM) for equalization enhanced impairment compensation

Speaker: Chunpo PAN (University of Toronto)



Equalizer enhanced impairments caused by larger laser linewidth has been a major obstacle for applying higher order modulation formats in coherent optical systems with digital chromatic dispersion compensation. In this work we present a code aided expectation maximization (CAEM) method to track phase noise in such systems. It is demonstrated that with 11% redundancy our method can increase the laser linewidth tolerance for 975 km transmission distance by 50%, or double system reach for a laser linewidth of 5 MHz. It is also found that 4-4-4-4 ring constellation has better performance compared to 16QAM or 2-6-8 ring constellations. The performance can be further boosted with the trade-off of code rate. Lastly, we show a few ways to decrease the complexity of our algorithm without diminishing the performance gain significantly such as reducing iterations and using low complexity codes.


July 19, 2013


The Chinese University of Hong Kong

2:30 p.m. to 4:30 p.m.

Room 713, William M. W. Mong Engineering Building (ERB)






Title: Direct-modulated waveguide-coupled microspiral lasers for on-chip optical interconnects

Speaker: Yu ZHANG, The Hong Kong University of Science and Technology



We have investigated direct-modulated waveguide-coupled microspiral lasers for on-chip optical interconnects.  Microspiral resonators, with a rotationally asymmetric shape and a waveguide direct gapless coupled to the notch, offer a great promise for potential compact unidirectional-emission on-chip laser sources.  Ring shaped p-contact is designed to improve the inject efficiency and laser performance.  We report room-temperature continuous-wave electrically injected AlGaInAs/InP waveguide-coupled microspiral laser with a radius ranging from 30 to 40 mm.  Small signal modulation with 3dB bandwidth exceeding 10 GHz was realized for the fabricated waveguide-coupled microspiral laser with a radius of 30 mm.  An open eye diagram at 15Gbit/s with bias current of 90 mA was also demonstrated at 15oC.


Title: Generation and transmission of optical M-ary RZ-DPSK signals using directly modulated chirp managed laser

Speaker: Wei JIA, The University of Hong Kong



We propose and experimentally demonstrate a novel approach to generate high speed M-ary RZ-DPSK signals using a commercial available chirp managed laser (CML), comprising a directly modulated distributed-feedback (DFB) laser (DML) and a passive optical filter. The CML based M-ary RZ-DPSK transmitter does not require any differential encoder, phase modulator (PM) or even Mach-Zehnder modulator (MZM) based pulse carver, thus significantly reducing power consumption, device complexity, and cost. The inherent phase-coding and pulse re-shaping properties are originated from the adiabatic chirp of the semiconductor laser and the narrow-bandwidth filter in the CML, respectively.


May 3, 2013


The University of Hong Kong

3:30 p.m. to 5:30 p.m.

CPD(Central Podium)2.45, 2/F, Centennial Campus



Title: Effect of the CW-seed's linewidth on the seeded generation of supercontinuum

Speaker: Xiaoming WEI, The University of Hong Kong



It has been shown that the SC generation can be manipulated by using a weak CW-seed experimentally and numerically. When it comes to the effect of the linewidth of the CW-seed source on the generated SC, however, no experimental analysis has been investigated yet, which is very important for the implementation of high quality SC. Here, based on both experimental and numerical studies, we investigate the effect of the linewidth of the CW-seed source on the temporal coherence and pulse-to-pulse fluctuation of the seeded SC.


Title: Carrierless Amplitude and Phase (CAP) Modulation and its Equalization Schemes for Short Range Optical Communication Systems

Speaker: Li TAO, The Hong Kong Polytechnic University



Carrier-less amplitude and phase (CAP) modulation has generated increasing interest because it allows relatively high data rate to be achieved using optical components of limited bandwidth. CAP signal can be generated by using a digital or analog filter and a higher order modulation can also be realized, thus reducing the complexity of computation and system structure considerably. However, CAP-based system is very sensitive to symbol timing offset and jitter and requires a flat channel frequency response. Therefore, adaptive equalizers are often necessary in mitigating such impairments. A basic CAP modulation system is introduced and several equalization methods are presented. Using the proposed equalization schemes, 10 Gb/s and 20 Gb/s CAP16 transmission is demonstrated experimentally.



March 1, 2013


City University of Hong Kong

3:30 p.m. to 5:30 p.m.





Title: Terahertz Bragg Gratings in Subwavelength Polymer Fiber

Speaker: Mr. Shu-Fan ZHOU, City University of Hong Kong



We demonstrate fiber Bragg gratings for use in the terahertz window. The notch-type gratings were written point-by-point in subwavelength polymer fiber using a KrF excimer laser. Devices having rejection ratios of up to 60dB with a few GHz bandwidth were observed at the lower end of THz range. Good agreement has been achieved between the simulated and experimental results. The scattering property of the grating was also characterized at frequencies above the Bragg resonance condition, which can potentially be applied in a spectrometer for the THz range.


Title:?Novel Fiber-Based Variable All-Optical Packet Buffer Based on Self-Phase-Modulation-Induced Spectral Broadening

Speaker: Dr. Kam-Hon TSE, The Chinese University of Hong Kong



We propose a novel optical delay control mechanism to realize variable all-optical packet buffering, in which the amount of optical delay is controlled by the input signal power level. It consists of a passive fiber delay loop followed by an optical power dependent filter, which is realized by means of two stages of self phase-modulation-induced spectral broadening and offset filtering. The feasibility of the proposed optical packet buffer has been investigated through numerical simulations and experiments. No polarization control and additional laser source are needed.


Nov. 2, 2012


The Hong Kong University of Science and Technology

3:30 p.m. to 5:30 p.m.

Rm 4018



Title: Epitaxial III-V-On-Silicon Waveguide Butt-Coupled Photodetectors

Speaker: Mr. Shaoqi FENG, The Hong Kong University of Science and Technology



We report silicon waveguide butt-coupled p-i-n InGaAs photodetectors epitaxially grown on silicon-on-insulator substrates by metalorganic chemical vapor deposition. The InGaAs absorption layer that is lattice-matched to InP is selectively grown on patterned SOI substrates, employing metamorphic growth of GaAs and InP buffer layers. We measure a dark current of 2.5 nA and a responsivity of 0.17A/W at 1550 nm wavelength upon bias voltage. This device exhibits a 3 dB bandwidth of 9 GHz. We demonstrate an open-eye diagram at 10Gb/s data rate upon?bias voltage.


Title: Optical Time-Stretch Confocal Microscopy For Biomedical Applications

Speaker: Mr Terence WONG, The University of Hong Kong



We demonstrate optical time-stretch confocal microscopy in the 1um spectral window for high-speed and high-resolution cellular imaging. In contrast to the prior demonstrations of time-stretch imaging, which all operated in the telecommunication band, the present work extends the utility of this imaging modality to a wavelength regime (~1um), which is well known to be the optimal diagnostic window in biophotonics. This imaging technique enables us to image the nasopharyngeal epithelial cells with cellular resolution (~2 um), at a line-scan rate of 10 MHz, and with a field of view as wide as ~0.44 mm x 0.1 mm. We also theoretically and experimentally characterized the system performance. As the low-loss dispersive fibers for the time-stretch process as well as other essential optical components for enhancing the imaging sensitivity are commonly available at 1um, time-stretch confocal microscopy in this wavelength range could usher in realizing high-speed cell imaging with an unprecedented throughput. Apart from that, in order to relax the stringent requirement on the digitizer, we demonstrate that by incorporating pixel super-resolution (SR) algorithm with multiple low-resolution time-stretch images, we can reconstruct high-resolution time- stretch images with significant improvement on the image quality.


Sept 7, 2012


The Hong Kong Polytechnic University

2:00 p.m. to 5:30 p.m.

Rm BC402




Title: OSNR Monitoring For QPSK And 16-QAM Systems In Presence Of Fiber Nonlinearities For Digital Coherent Receivers

Speaker: Mr. Zhenhua DONG, The Hong Kong Polytechnic University

OSNR monitoring is indispensable for coherent systems to ensure robust, reliable network operation and potentially enable impairment-aware routing for future dynamic optical networks. In a long-haul transmission link with chromatic dispersion (CD) and fiber nonlinearity, it is difficult to distinguish between amplifier noise and fiber nonlinearity induced distortions from received signal distributions even after various transmission impairment compensation techniques, thus resulting in grossly inaccurate OSNR estimates. Based on the received signal distributions after carrier phase estimation (CPE), we propose to characterize the nonlinearity-induced amplitude noise correlation across neighboring symbols and incorporate such information into error vector magnitude (EVM) calculation to realize fiber nonlinearity-insensitive OSNR monitoring. For a transmission link up to 1600 km and signal launched power up to 2 dBm, experimental results for 112 Gb/s polarization-multiplexed quadrature phase-shift keying (PM-QPSK) demonstrate an OSNR monitoring range of 10-24 dB with a maximum estimation error below 1 dB. For 224 Gb/s PM-16-quadrature amplitude modulation (PM-16-QAM) systems, simulation results demonstrate an OSNR monitoring range of 18-28 dB with a maximum estimation error below 1 dB. Tolerance of the proposed OSNR monitoring technique to different pulse shapes, timing phase offsets, polarization dependent loss (PDL), polarization-mode dispersion (PMD) and WDM effects are also investigated through simulations.

Title: Oversampled Random Bit Generation Using an Optically Injected Semiconductor Lasers in Chaos

Speaker: Mr. Xiaozhou Li, City University of Hong Kong


Random bit generators play a significant role in a variety of areas including numerical simulation, encryption, and secure communication. Recently, semiconductor lasers in chaotic dynamics were investigated for high-speed random bit generation. Previous studies used optical feedbacks to perturb the lasers into chaotic dynamics, but such optical feedbacks often led to undesirable autocorrelations at the feedback round-trip time. In this talk, we report a new experimental demonstration of random bit generation using an optically injected semiconductor laser without optical feedback. The use of optical injection advantageously gives no inherent feedback round-trip time in the chaotic waveforms. The scheme requires no complicated postprocessing and has no stringent requirement on the electronic bandwidth. Using an 8-bit analog-to-digital converter of a front-end bandwidth of only 1.5 GHz, the chaotic waveform from the laser is sampled at 10 GHz, which is an oversampling because it exceeds the Nyquist rate. Nonetheless, by retaining 3 least significant bits and performing exclusive-or operations on consecutive samples, random bits are generated at an aggregated output bit rate of 30 Gbps. The output bits are verified to pass the standard randomness tests from the National Institute of Standards and Technology.


July 6, 2012


The Chinese University of Hong Kong

4:30 p.m. to 6:00 p.m.

Rm 1009, Mong Man Wai Engineering Building

Title: Silicon-on-Insulator Multimode Interferometer Waveguides Array Optical Tweezers for Two-Dimensional Microparticle Trapping and Manipulation

Speaker: Mr. LEI Ting, Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology

We adapt silicon-on-insulator 100 micron-core multimode interferometer waveguides for two-dimensional microparticle trapping and manipulation. The waveguide mode fields in 1550nm wavelengths enable thermal flow assisted optical trapping and manipulation of 1 micron and 2.2 micron sized polystyrene microparticles in a thin fluidic cell. The multiple physics process (electromagnetic filed, heat transfer, microfluidic flow) within this optical tweezer system are investigated using finite element method simulation. Then microparticle trapping experiment in heavy water is demonstrated to verify the simulation result.


Title: Optical Physical-layer Network Coding: Principle, Demonstration, and Research Problems

Speaker: Mr. LIU Zhixin, Department of Information Engineering, The Chinese University of Hong Kong


Physical-layer network coding (PNC) has been an active research area in both information theory and wireless communications in the past few years. However, its application in optical communications has not yet been explored. Our recent paper proposes and demonstrates an optical PNC prototype for multicast protection in optical flow/burst/packet switching networks. Different from conventional theoretical PNC studies, our proposed optical PNC system does not require bit synchronization and demonstrate an optical PNC experiment for the first time. In this talk, we will first talk about the idea and possible applications of optical PNC. Then the experiment will be shown and the some research problems will be discussed.


June 24, 2010


The Chinese University of Hong Kong


5:00 p.m. to 6:00 p.m.

Rm 503, Ho Sin Hang Engineering Building

Title: All-optical signal processing using photonic crystal fiber based Mach-Zehnder interferometer
Speaker: Mr. DU Jiangbing, Department of Electronic Engineering, The Chinese University of Hong Kong
Photonic crystal fiber based Mach-Zehnder interferometer (PCF-MZI) is an in-line, all-fiber and coupler free device which, as a delay interferometer (DI), has a relative delay introduced by the index difference between the core mode and the cladding mode of the PCF. The in-fiber PCF-MZI also offers enhanced thermal stability and performs favorably for optical sensing. To date, applications of the in-fiber PCF-MZI is mainly focused on optical sensing rather than on communications, which is the major objective of this work. We fabricated PCF-MZIs with different PCF lengths to introduce different delays for optical signal processing. A PCF-MZI with 300cm PCF for introducing a ~90ps delay has been used for 10 Gb/s DPSK signal demodulation. Error-free demodulations for RZ- and NRZ-DPSK signals has been realized with minor fluctuation (<1.5dB) of the receiver sensitivity. Another PCF-MZI with 165cm PCF gives a relative delay of ~50ps, which has been used for RZ-to-NRZ and NRZ-to-PRZ pulse format conversions. Using the in-fiber PCF-MZI, we also realized optical time domain multiplexing (OTDM) at different bitrates, which offers comparable performance to commercial multiplexers.

Title: Optical Signal-to-Noise Ratio Monitoring
Speaker: Mr. SUI Qi, The Hong Kong Polytechnic University

April 29, 2010


City University of Hong Kong


5:00 p.m. to 6:00 p.m.

LT 12, Academic Building, The City University of Hong Kong.

Title: Novel Applications of Diffractive Optical Elements in Optical Fiber Communications

Speaker: Mr. WEN Fung, Jacky, City University of Hong Kong


Title: All-Fiber Based Ultrashort Pulse Generation and Chirped Pulse Amplification through Parametric Processes

Speaker: Mr. Zhou Yue, The University of Hong Kong


October 29, 2009


The Hong Kong University of Science and Technology


5:00 p.m. to 6:00 p.m.

LTH (Lift 27-28), Academic Building

Title: Monolithic Light Emitting Diode Micro-display on Active Matrix Substrate Using Flip-Chip Technology

Speaker: Mr. Zhaojun Liu, Photonic Technology Center, ECE Department, The Hong Kong University of Science and Technology.

Abstract: We report a GaN-based, active matrix programmed 8℅8 monolithic LED micro-display using flip-chip techonology. The active matrix (AM) panel consists of 8℅8 driving circuits which were fabricated on a single crystal silicon wafer and in the configuration of two p-type metal-oxide-silicon (PMOS) transistors and one capacitor. The LED micro array includes 8℅8 blue LED (Emission Wavelength = 440nm) pixels with the n-electrodes connected together and individually separated p-electrodes. The LED micro array was then flipped onto the AM panel using standard flip-chip technology and the p-electrodes of the LED pixels are connected to the output of the driving circuits on the AM panel. The fabricated prototype can be individually lighted up or fully powered with excellent emission uniformity.


Title: Various Waveguide Gratings for Coupling between Silicon Waveguides and Vertical Optical Fibers

Speaker: Mr. Xia Chen, The Chinese University of Hong Kong.

Abstract: One of the major challenges in the application of integrated optoelectronics based on SOI platform is the efficient coupling of light to/from an optical fiber or other types of light sources, because of the relatively small cross section of the submicron-sized silicon waveguide. Waveguide grating couplers have been used to tackle this problem. Encouraging progress was achieved in recent years. Different types of grating couplers will be introduced, including our recent work on non-uniform focusing grating couplers and single-etch nanoholes grating couplers. The design process will be presented together with the numerical and experimental results.


June 25, 2009


The Chinese University of Hong Kong


5:00 p.m. to 6:00 p.m.

Rm 503, Ho Sin Hang Engineering Building

Title: Generation and Applications of a Time- and Wavelength-Interleaved Pulsed Laser Source

Speaker: Mr. Gordon K. P. Lei , The Chinese University of Hong Kong

Abstract: Because of the increasing demand on internet protocol and multimedia services, the bandwidth requirement on electronics has been increasing dramatically in recent years. Different approaches have been demonstrated to relax the requirement, including different multiplexing and repetition rate multiplication techniques. In this presentation, we will report how a time- and wavelength-interleaved pulsed laser source can help to relax the bandwidth requirement. We will discuss the generation of this pulsed laser source and demonstrate its applications in optical signal processing at 40 Gb/s.


Title: Simulation of all-optical packet switching using Fabry-Perot laser diode at 10Gb/s

Speaker: Mr. Liqing Gan, Hong Kong Polytechnic University

Abstract: All-optical packet switching (AOPS) in which both header processing and packet switching are carried out in the optical domain is a promising technology to handle the bursty traffic of future optical networks because it does not require O-E-O conversion and hence can overcome the electronic bottlenecks. Even the most rudimentary form of AOPS requires (i) nonlinearity in order for light to control light which is needed in header processing, (ii) optical memory to "remember" the result of header processing to affect the whole packet, and (iii) switching of packets based on decision of header processor, eg. on/off switching based on change in amplifier gain. The properties of injection locked Fabry-Perot laser diode (FP-LD) could be used to implement the AOPS. We have experimentally demonstrated using a single FP-LD for both header processing and packet switching and also a FP-LD for header processing and an SOA for packet switching. The highest demonstrated header rate is 10 Gb/s. In this study, we adopt a rate equation model to numerically investigate the all-optical packet switching with all-optical header processing using FP-LDs at 10 Gb/s.



April 30, 2009


The University of Hong Kong


5:00 p.m. to 6:00 p.m. in

Room 603, Chow Yei Ching Building


Title: Versatile Parametric Wavelength Exchange: A 160-Gb/s OTDM De-Multiplexer

Speaker: Mr. Mengzhe Shen, The University of Hong Kong

Abstract: Parametric wavelength exchange (PWE) has been demonstrated as a versatile device in providing different functionalities. In this paper, we will concentrate, numerically and experimentally, on one of  these functionalities, namely, all-optical time de-multiplexing of 160-Gb/s return-to-zero (RZ) signals based on a pulsed-pump PWE in a 400-m highly-nonlinear dispersion-shifted fiber (HNL-DSF).  Experimental results show power penalties ?/span> 2.7 dB at bit-error rate  (BER) of 10-9 for all de-multiplexed 10-Gb/s RZ signals. We also derive theoretical expressions for the conversion/residual efficiencies and investigate the impact of pump pulse width and phase-mismatch on these efficiencies. Furthermore, the impacts of pulsed-pump wavelength and power level on the characteristics of the switching window are investigated numerically. As a result, the de-multiplexer can be easily upgraded to an add-drop multiplexer (ADM) because of the complete exchange nature of PWE, which is justified by the surviving channels?waveform performance.


Title: DPSK demodulator based on DANLM

Speaker: Mr. Yongheng Dai, The Chinese University of Hong Kong

Abstract: Differential phase-shift keying (DPSK) modulation format is promising for use in future fiber communication networks. A number of devices have been previously proposed to demodulate the signals. The delay-asymmetric nonlinear loop mirror (DANLM) is a novel device that provides demodulation for bit-rate variable DPSK signals. Since its initial demonstration in 2008, obstacles of the implementation and advantages of demodulation performance have been further investigated. We will report the recent progress of DANLM in the seminar, including polarization-insensitive operation and wideband DPSK demodulation.


February 26, 2009


The Hong Kong University of Science and Technology


5:00 p.m. to 6:00 p.m. in Room 4480 (4/F, lift 25,26) Academic Building

Title: Stress-induced Birefringence in Polymer optical Waveguides

Speaker: Mr. Md. Faruque Hossain, City University of Hong Kong


Stress-induced birefringence is an important issue in polymer integrated-optic devices for application in optical communication systems. The stresses are mainly generated in the fabrication process due to polymerization shrinkage and mismatch in properties of constituent materials. However, a good quantitative understanding of such stress-induced birefringence is very important for the design purposes and to optimize the fabrication process. In this presentation, firstly, a more realistic finite element model will be demonstrated to accurately predict the stresses induced over the entire sequential fabrication process. Then the stress-induced birefringence characteristics are investigated for different strip and rib waveguides. Finally, the accurate design of some non-birefringent polymer waveguides will be shown by taking the stress-effects into account, in where the stress free assumption completely fails. As a generic in nature, the approach would also enable optimized design of more complex integrated-optic devices from the standpoint of material systems, waveguide geometry and process parameters.


Title: Transflective Liquid Crystal Displays

Speaker: Mr. Tao Du, Centre for Display Research, HKUST

Abstract:  Transflective liquid crystal displays (LCDs) were first demonstrated in the year 1999. Transflective LCDs are commonly used in mobile and portable applications because of their superior performance in both indoor and outdoor environment. Normally, the pixels of the traditional transflective LCDs are separated into the transmissive and reflective sub-pixels. The transmissive sub-pixels in a transflective display are transmitting with backlight illumination and the reflective sub-pixels are reflecting light from the environment under ambient illumination.

Double cell gap approach is applied in conventional transflective LCDs to get a good match of the transmittance/reflectance versus voltage curves (TVC/RVC). However, together with the good performance of such double cell gap approach there is the drawback of complex fabrication process. In recent years, various transflective LCDs with single cell gap using two different modes had been proposed.

In our group, we invented the multimode configuration using twist nematic (TN) and low twist nematic (LTN) modes.  In the configuration, LTN mode with 60o twist is applied to the reflective part while the ECB mode is applied to the transmissive part. The alignment domains in pixels were realized by photo-alignment technique. After that, we also tried the single mode single cell gap approach, and finally the 75o single mode transflective configuration was invented. Both these two configurations show high transmittance/reflectance, high contrast ratio and wide viewing angle. Also the fabrication is not so difficult. Thus they can be applied in TFT transflective displays.

October, 30, 2008


The Hong Kong Polytechnic University

Title: Pedestal Free Pulse Compression in Nonlinear Fibers And Nonlinear

Fiber Bragg Gratings

Speaker: Ms. Li Qian, The Hong Kong Polytechnic University

Abstract: Through the self-similar analysis, we have theoretically investigated the linearly chirped Bragg solitary pulses near the photonic bandgap (PBG) structure of FBG. Efficient Bragg soliton pulse compression can be achieved with appropriate grating induced dispersion, such as the exponentially decreasing dispersion. From a practical point of view, the stepwise approximation of the exponentially decreasing dispersion is carried out by concatenation of grating segments with different dispersion coefficients. For the proposed compression scheme, the input pulse must be pre-chirped in prescribed manner, and a simple pre-chirper, such as a linear fiber or grating, is used to add the required chirp profile to initial chirp-free hyperbolic secant or Gaussian pulse.?Higher order nonlinearities must be considered if the optical pulse intensity is high or the nonlinear coefficients of the materials are large, for instance, in semiconductor doped glasses. More recently we have investigated the existence of chirped bright solitons in cubic-quintic nonlinear media with exponentially decreasing dispersion. From a stability analysis, we show that the soliton in the anomalous dispersion regime is stable whereas the soliton in the normal dispersion regime is unstable. Numerical simulation results confirm that the competing cubic-quintic nonlinearities stabilize the chirped soliton pulse propagation against perturbations of the initial soliton parameters. In addition, we study the possibility of rapid compression of Townes solitons by the collapse phenomenon in the exponentially decreasing dispersion. We find that the collapse could be postponed if the dispersion increases exponentially.


Title: Wide-Band Generation of Pico-second Pulse via Idler Generation in optical parametric amplifier

Speaker: Zhou Yue, The University of Hong Kong

Abstract: A wide-band generation of pico-second pulse using optical parametric amplifier (OPA) was demonstrated. High quality pulse was generated at 85-nm away from the pump with pulsewidth narrower than that of the pump.

August 28, 2008, 5pm


City University of Hong Kong

Title: UV-Written Long-Period Waveguide Grating Coupler

Speaker: Mr. Billy C. K. CHOW, City University of Hong Kong

Abstract: We demonstrate an optical broadband Add/Drop multiplexer based on a UV-written long-period waveguide grating coupler. The coupler is formed with two parallel long-period polymer waveguide gratings. A maximum coupling efficiency as high as 80% has been achieved and the resonance wavelength can be tuned over a wavelength range of 120 nm with a temperature control of 22o for the TE polarization. In particular, a coupler with a polarization-insensitive resonance wavelength at a specific temperature is also demonstrated. The coupler has the potential to be further developed into practical broadband add/drop multiplexers.


Title: Silicon Cross-Connect Filters and Switches Using Microring Resonator Coupled Multimode-Interference-Based Waveguide Crossings

Speaker: Xu Fang, Hong Kong University of Science and Technology

Abstract: The throughput, power dissipation, and latency are becoming most critical issues in high-performance computing system design.  The inherent bandwidth and power dissipation from the metallic interconnect are limiting progress in the interconnection networks performance for high-performance computers. Silicon photonics offers an alternative optical solution to on-chip interconnection using mature complementary metal-oxide-semiconductor (CMOS) fabrication technologies. Here, we focus on our work on the architecture of cross-connect filters and matrix switch using cascaded microrings coupled to low-loss low-crosstalk multimode-interference-based waveguide crossings on a silicon chip. We demonstrated cross-connect filters in silicon-on-insulator substrate. The MMI-based filters exhibit much lower junction induced crosstalk level compared with plain crossing filters indicated by the symmetrical lineshapes in the drop-port spectra of the MMI-based filter. We also vision the filters can be reconfigurable using plasma dispersion effect and cascaded into matrix switch.  We discuss prospects of using such matrix switch as a 5naps?>rof hctiws tiucric lacitpo-ortcele 5 elbissop dna seussi lacigolonhcet eniltuo osla dna ,gnitupmoc eroc-ynam .snoitagitim




June 26, 2008, 5pm


The Chinese University of Hong Kong

Title: Non-reciprocal Optical Modulation for Integrated Re-Modulation in Optical Access Networks

Speaker: Mr. Lin Xu, The Chinese University of Hong Kong
Abstract: Currently deployed Time-Division-Multiplexed Passive-Optical-Networks (TDM PON) is based on bandwidth sharing among multiple users and cannot satisfy the future demand (e.g. HDTV streaming, p2p, 3D online gaming etc). Next Generation Wavelength-Division-Multiplexed Passive Optical Networks (WDM PON) can provide higher bandwidth over longer distances because each user is assigned a specific wavelength. However, the challenge is its expensive wavelength-specific DWDM optical components. Based on colorless optical network unit, we proposed and demonstrated the "Non-reciprocal optical modulation for integrated re-modulation in optical access networks". The novel optical network unit have the advantage of simple structure and easy for integration.

Title: Characterization the Raman-assisted Fiber Optical Parametric Amplifiers
Speaker: Mr. Shaohao Wang, The Hong Kong Polytechnic University
Abstract: We derived a simple theoretical model to characterize the Raman-assisted fiber optical parametric amplifier (RA-FOPA).  We also proposed the contour gain maps of the overall gain and combined gain difference to investigate the gain behavior of RA-FOPAs.  We find the 0-dB combined gain difference line bonder the region of gain saturation. By keeping the Raman and parametric pumps out of the saturation region and the parametric gain limit, we demonstrated that the theoretical model can be used to design and optimize RA-FOPAs for large gain and large gain enhancement. A 6.4 dB combined gain enhancement was  demonstrated of  when combining a Raman amplifier and a continuous-wave (CW) pumped FOPA. We also demonstrated a 3.6-dB noise figure as well as a 21.2 dB on-off gain in a RAFOPA by suppress input parametric pump noise.

April 24, 2008, 5pm


University of Hong Kong


Title: Double-Notch-Shaped Microdisk Resonator-Based Devices in Silicon-on-Insulator

Speaker: Mr. Xianshu LUO, HKUST

Abstract: Compared with conventional circular microdisk resonators, double-notch-shaped microdisk resonators possess the advantage of gapless coupling between input/output waveguides and microresonators, yet still keep high quality factor cavity resonances.We demonstrate double-notch-shaped microdisk resonator-based filters in silicon-on-insulator. Our filter demonstrates whispering-gallery-like modes with Q exceeding 104. We also propose and fabricate electro-optic modulators using this structure integrated with a metal-oxide-semiconductor capacitor.


Title: Simultaneous Optical Delay and NRZ-RZ Format Conversion via Cross-Polarization Modulation and Pulse Pre-chirp

Speaker: Mr. Bill P. P. KUO, HKU

Abstract: All-optical tunable delay plays important roles for enabling high-throughput optical routing, such as buffering for contention resolution and timing synchronization. We propose and demonstrate a widely-tunable optical delay using cross-polarization modulation-based wavelength converter (XPolM-WC) and pulse pre-chirping for compensating chromatic dispersion in fiber. Thanks to wide-band operation provided by XPolM-WC, large delay range up to 8.6 ns is obtained. Meanwhile, pulse pre-chirping technique helps to attain error-free operation over the whole delay range, and NRZ-to-RZ format conversion is achieved due to temporal compression of chirped pulse.






IEEE Photonics Society Conference Listings

Useful Links


IEEE (Hong Kong)

IEEE Photonics Society

Hong Kong Optoelectronics Association

Contact Person:

Prof. Alan P T LAU: eeptlau@polyu.edu.hk