Shanghai Synet Optics Technology Corporation

Shanghai, China

Shanghai Synet Optics Technology Corporation

Shanghai, China
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Wang Z.,CAS Shanghai Institute of Optics and fine Mechanics | Wang Z.,University of Chinese Academy of Sciences | Pan Z.,CAS Shanghai Institute of Optics and fine Mechanics | Ye Q.,CAS Shanghai Institute of Optics and fine Mechanics | And 7 more authors.
Chinese Optics Letters | Year: 2015

A novel distributed passive vehicle tracking technology is proposed and demonstrated. This technology is based on a phase-sensitive optical time domain reflectometer (Φ-OTDR) that can sense and locate vibrations. Two algorithms, dynamic frequency-space image and 2D digital sliding filtering, are proposed to distinguish a car's moving signals from severe environmental noises and disturbances. This technology is proved effective by field experiments for tracking a single car and multiple cars. This work provides a new distributed passive way for real-time vehicle tracking and this technology will be extremely important for traffic controlling and public safety in modern society. © 2015 Chinese Optics Letters.


Hao Y.-Q.,Zhengzhou University of Light Industry | Ye Q.,CAS Shanghai Institute of Optics and fine Mechanics | Pan Z.-Q.,CAS Shanghai Institute of Optics and fine Mechanics | Cai H.-W.,CAS Shanghai Institute of Optics and fine Mechanics | And 2 more authors.
Chinese Physics B | Year: 2014

The digital coherent detection technique has been investigated without any frequency-scanning device in the Brillouin optical time domain reflectometry (BOTDR), where the simplex pulse codes are applied in the sensing system. The time domain signal of every code sequence is collected by the data acquisition card (DAQ). A shift-averaging technique is applied in the frequency domain for the reason that the local oscillator (LO) in the coherent detection is fix-frequency deviated from the primary source. With the 31-bit simplex code, the signal-to-noise ratio (SNR) has 3.5-dB enhancement with the same single pulse traces, accordant with the theoretical analysis. The frequency fluctuation for simplex codes is 14.01 MHz less than that for a single pulse as to 4-m spatial resolution. The results are believed to be beneficial for the BOTDR performance improvement. © 2014 Chinese Physical Society and IOP Publishing Ltd.


Pan Z.,CAS Shanghai Institute of Optics and fine Mechanics | Ye Q.,CAS Shanghai Institute of Optics and fine Mechanics | Cai H.,Shanghai Synet Optics Technology Corporation | Qu R.,CAS Shanghai Institute of Optics and fine Mechanics | Fang Z.,CAS Shanghai Institute of Optics and fine Mechanics
IEEE Photonics Technology Letters | Year: 2014

fiber ring with an extremely low reflectivity fiber Bragg grating inserted as a slow-light component is proposed and demonstrated to be used as a cavity mirror with long delay for narrowing fiber laser linewidth. Due to the recirculating propagation and resonance in the ring composed of a low split ratio coupler, the composite ring provides not only a high enough reflectivity and extremely narrow bandwidth for laser oscillation, but also an enlarged group delay. The effective reflectance and group delay of the composite ring are discussed theoretically. Its effect of laser linewidth narrowing is verified experimentally in a laser with the composite fiber ring and a high reflectivity fiber Bragg grating as cavity mirrors. Its line shape, relative intensity noise (RIN), and frequency noise (FN) are measured, showing the full-width at half-maximum linewidth of 150 Hz, RIN and FN of less than-125 dB/Hz at 500 Hz and 30 Hz/Hz at 500 Hz, respectively. © 2014 IEEE.

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