Research
Random Air Turbulence in Free-space Optical Communications
Principle Investigator: Dr. Shiming Gao, Zhejiang University, P.R. China (Sept.2016 - June.2017)
Random air turbulence is an atmospheric phenomenon which dampens the amplitude and phase quality of optical signals in free space. This project aims at studying the nature of random air turbulence using Kolmogorov's statistical model in fluid mechanics. In this work, we used MATLAB to generate Komolgorolov random phase noise of atmospheric turbulence, thus simulating signal channel performance for coherent signals. Further research would focus on signal recovery, data extraction, and parametric optimization of optical coherent communication systems.
Quantum Entangled Source Based on a Dual-Sagnac Structure
Principle Investigator: Dr. Chee Wei Wong, UCLA, United States of America (Summer 2016)
Quantum entangled sources are increasingly essential for applications in quantum information and quantum computation, including quantum key distribution (QKD), quantum teleportation, and linear optics quantum computing. This study demonstrates a simple and potentially super-bright parametric down-conversion source of polarization-entangled photons based on a dual-Sagnac interferometer. By pumping type-II phase-matched periodically poled KTiOPO4 (PPKTP) waveguide on both ends with counter-propagating beams, this source cancels out higher order entangled terms, thus yielding a bright flux at rather high quantum-interference visibility. I won Outstanding Research and Presentation Award limited to 8 out of 98 CSST attendees.
Free-space Optical Communication Link Using Amplified Modulating Retro-reflector
Principle Investigator: Dr. Shiming Gao, Zhejiang University, P.R. China (May. 2015 - May. 2016)
Modulating retro-reflector (MRR) technology in free-space optical communications is competent, for it combines an optical retro-reflector with a modulator to reflect modulated optical signals directly back to the transceiver, thus simplifying the terminal end structure. This work proposed and experimentally demonstrated an FSO link for on-off keying (OOK) signals using a RSOA-based amplified MRR (AMRR), with considerable power penalty and bit error rate. The signal at the terminal is modulated on the optical carrier from the transceiver, and transmitted back for detection.
Application of Blood Typing with a Smartphone Camera
Principle Investigator: Dr. Longhua Tang, Zhejiang University, P. R. China (Oct. 2014 - Sept. 2015)
Different type of blood drops interacts with a specially made chemical sample paper, and performs different eluting length. The paper is captured by a smartphone camera, and an application in the smartphone would determine the blood type according to the length of red bars. This handy application helps people type their blood at home, instead of queuing up in an overcrowded hospital.