A5102016940- Optical Wireless Communication Technologies
- Optical Systems and Laser Technology
- Advanced Optical Sensing Technologies
- Underwater Vehicles and Communication Systems
- Atomic and Subatomic Physics Research
- Quantum optics and atomic interactions
- Semiconductor Lasers and Optical Devices
- Ocular and Laser Science Research
- Adaptive optics and wavefront sensing
- Ionosphere and magnetosphere dynamics
- Optical Network Technologies
- Solid State Laser Technologies
- Blind Source Separation Techniques
- Particle accelerators and beam dynamics
- Magnetic confinement fusion research
- Stellar, planetary, and galactic studies
- Advanced Frequency and Time Standards
- Neural Networks and Reservoir Computing
- Underwater Acoustics Research
- Plasma Diagnostics and Applications
- Water Quality Monitoring Technologies
Chinese Academy of Sciences
2016-2021
Institute of Plasma Physics
2021
Shanghai Institute of Optics and Fine Mechanics
2007-2019
University of Chinese Academy of Sciences
2019
Guilin University of Electronic Technology
2006-2007
Guilin University
2006
We designed a photon-counting receiver system for long-distance underwater wireless laser communication at different code rate Reed-Solomon (RS) and low-density parity check (LDPC) codes. The symbol error (SER) performance of the LDPC RS codes with signal-to-noise ratios was analyzed. effects background noise, pulse stretching, frame synchronization were considered in our system. A water tank experiment confirmed that 1/2-code-rate (255,127) is an excellent coding strategy distances range...
Optical pumping with circularly polarized light has been used to enhance the brightness of sodium laser guide star. But benefit is reduced substantially due precession atoms in geomagnetic field. Switching between left and right circular polarization at Larmor frequency proposed improve return. With ESO's star system Paranal as example, numerical simulation shows that return flux increased when angle field beam larger than 60°, much 50% 90°. The proposal significant since most astronomical...
Magnetic resonance of sodium fluorescence is studied with varying laser intensity, duty cycle, and field strength. A magnetometer based on a vapor cell filled He buffer gas demonstrated, using single amplitude-modulated beam. With 589 nm tuned at the D1 or D2 line, magnetic inferred from variation fluorescence. sensitivity 150 pT/Hz achieved line. The work an important step toward sensitive remote magnetometry mesospheric sodium.
In long-distance, high-speed underwater laser communication, because of the strong absorption and scattering processes, pulse is stretched with increase in communication distance decrease water clarity. The maximum bandwidth limited by laser-pulse stretching. Improving rate increases intersymbol interference (ISI). To reduce effect ISI, Viterbi equalization (VE) algorithm used to estimate maximum-likelihood receiving sequence. Monte Carlo method simulate stretching received at a wavelength...
Abstract Remote detection of geomagnetic fields in the mesosphere would provide a powerful tool for mapping and interpreting Earth's lithospheric magnetic fields, monitoring disturbances conjunction with aurora, making long‐term measurements ionospheric currents at polar regions. Based on gated photon counting direct frequency sweep, remote magnetometry scheme precession mesospheric sodium was demonstrated. The technique has an advantage background light suppression potential to achieve...
We design and demonstrate a long-distance underwater optical communication system with photon-counting receiver. Monte-Carlo simulations are conducted to determine parameters estimate performance. According the simulation results, Q-switched all solid state 532nm laser pulse energy of 100uJ@10kHz is used as source transmitter. A telescope 1° field view, 100mm clear aperture, photon counting detector collect in then present an experimental implementation long tank filled clean water. The...
One fast simulation method using Markov chains was introduced to simulate angular, energy, and temporal characteristics of pulsed laser beam propagation underwater. Angular dispersion photons with a different number collisions calculated based on scattering function the state transition matrix chains. Temporal distribution energy receiving plane were obtained, respectively, by use novel successive layering model ratio. The validity this verified comparing it Monte Carlo ray tracing (MCRT)...
The roughness of sea surface affects the optical property exiting upward laser, which constrains application LIDAR and Laser Communication in ocean. paper designs one pool test to study influence sea-air interfaces develops a corresponding geometric model. It analyzes laser through interface systematic. Results show that wavy will affect beam spreading, pointing scintillation when transmitting boundary. Further, experiment results water tank with man-made wave incident angle divergence are...
In this paper, we study influences of inherent optical properties (IOP) seawater and parameters laser pulse on characteristic after underwater propagation. Besides, achievable transmission distances under different conditions are simulated. Regard single energy, initial duration far field divergence angle the transmitted as inputs, temporal spatial distribution receive plane outputs, channel can be treated a linear time invariant (LTI) system. The response to with unit far-field 0 is impulse...
This paper studies the pulse interval modulation scheme for wireless laser communication between two nodes. (PIM) is a modified version of position (PPM) data and intended fast, low power reliable transmission with simple, minimum low-cost hardware implementation. tries to introduce one methods how realize PIM by use microcontroller. At first, this technique can effectively improve synchronization puzzles confronted during process demodulation. The second, method coding efficiency system....
Laser remote sensing underwater acoustical signal is one effective way to recognize targets and realize on-board active scanning, acquisition, pointing tracking over a wide range. By the research of theoretical simulation PC, fundamental experiment system constructed, which validates feasibility laser detection acoustic signal. The size location diaphragm are particularly discussed optimum aperture was developed. affection incidence beam width also analyzed. selecting very incident angle...
The efficiency of optical pumping that enhances the brightness sodium laser guide star with circularly polarized light is reduced substantially due to precession atoms in geomagnetic field. Switching between left and right circular polarization at Larmor frequency proposed improve photon return. With ESO's cw system Paranal as example, numerical simulation for both square-wave sine-wave modulation conducted. For switching case, return flux increased when angle field beam larger than 60°,...
The optical Pulse Position Modulation (PPM) is applied widely in Free Space Optical communication (FSO) with the low average power and high peak power. transmitted PPM information depends on location of coming pulse signals fixed period. Both receiver transmitter should been kept time slot synchronization frame demodulation. Because channel very complex, received width will be stretched randomly. We design realize one digital modulation sensitivity using technology PMT, A/D converter, DSP....
A technique is developed to detect underwater acoustic signals by utilizing the resultant surface perturbations. It uses light wave in air and under water. Because two best channels are combined together, it an ideal method for remotely detecting signals. The signal can cause perturbations at water-air interface. These result amplitude modulation effect on a laser beam reflected water surface. modulated be detected using direct intensity method. Based theory of laser, detection system was...
A down-link propagation model was set based on Monte Carlo simulation, and the comprehensive influence of sea wave, water channel receiver system has been considered. The validated by practical received results.
Magnetic resonance of sodium fluorescence is investigated and a magnetometer based on vapor demonstrated. The study motivated by remote magnetometry with mesospheric sodium. Results on-sky tests are reviewed.