Shichen Li

Fiber Bragg grating for spectral phase optical code-division multiple-access encoding and decoding

A new method for realizing spectral phase optical code-division multiple-access (OCDMA) coding based on step chirped fiber Bragg gratings (SCFBGs) is proposed and the corresponding encoder/decoder is presented. With this method, a mapping code is introduced for the m-sequence address code and the phase shift can be inserted into the subgratings of the SCFBG according to the mapping code. The transfer matrix method together with Fourier transform is used to investigate the characteristics of the encoder/decoder. The factors that influence the correlation property of the encoder/decoder, including index modulation and bandwidth of the subgrating, are identified. The system structure is simple and good correlation output can be obtained. The performance of the OCDMA system based on SCFBGs has been analyzed.

10 GHz over 58 nm supercontinuum pumped by a regeneratively mode-locked fiber laser

In this work, 10 GHz over 58 nm 20 dB bandwidth supercontinuum (SC) is generated in 4.5 km dispersion-shifted fiber (DSF) pumped by a 10 GHz regeneratively mode-locked fiber laser (RMLFL). The optimized SC with 51.5 nm 20 dB bandwidth is obtained by properly adjusting the pump power. A 25 nm spectral region from 1535 nm to 1560 nm and a 12nm spectral region of 1567-1579 nm with ±3 dB uniformity are generated. 10GHz, over 30 channels were sliced by an array waveguide grating (AWG) with 100 GHz channel spacing. Timing jitter of each channel is less than 1.25 ps.

Studies of 10GHz RZ pulse source based on regeneratively mode-locked fiber laser

In this paper, the application in return-zero (RZ) light source based on regeneratively mode-locked fiber laser (RMLFL) is demonstrated. By using Mach-Zehnder modulator and pseudo-random code modulation, the back-to-back eye-diagrams with good performances are obtained and RZ format light source with pulse duration of 5ps based on RMLFL is achieved, which quite meets the requirements of 10 Gbit/s long haul transmission. Furthermore, such a 10 GHz RZ source could be multiplexed into 40 GHz RZ light source simply by 4 fold optical time division multiplexing (OTDM).