A wide-dynamic-range CMOS image sensor（CIS） based on synthesis of a long-time and a short-time exposure signal in the floating diffusion（FD） of a five-transistor active pixel is proposed.With optimized pixel opera...A wide-dynamic-range CMOS image sensor（CIS） based on synthesis of a long-time and a short-time exposure signal in the floating diffusion（FD） of a five-transistor active pixel is proposed.With optimized pixel operation,the response curve is compressed and a wide dynamic range image is obtained.A prototype wide-dynamic-range CMOS image sensor was developed with a 0.18μm CIS process.With the double exposure time 2.4 ms and 70 ns,the dynamic range of the proposed sensor is 80 dB with 30 frames per second（fps）.The proposed CMOS image sensor meets the demands of applications in security surveillance systems.展开更多
Many methods have been suggested to reduce dispersion in optical fiber communication. Among these methods, chirped fiber grating (CFG) is a promising scheme. This paper describes a linearly chirped fiber grating with...Many methods have been suggested to reduce dispersion in optical fiber communication. Among these methods, chirped fiber grating (CFG) is a promising scheme. This paper describes a linearly chirped fiber grating with 95% reflectivity and 0.3 nm bandwidth written using a double exposure method with a uniform phase mask. The CFG resonant wavelength is 1554.5 nm and dispersion is 1700 ps/nm. Dispersion compensation in a 10-Gb/s optical transmission system has been demonstrated using this chirped fiber grating. The power penalty induced by the dispersion compensation after 180-km transmission is 1 dB. This is the first report describing dispersion compensation of 180 km at 10-Gb/s optical transmission now-return to zero (NRZ) system in China.展开更多
基金supported by the National Natural Science Foundation of China(Nos.60806010,60976030)the Tianjin Innovation Special Funds for Science and Technology,China(No.05FZZDGX00200).
文摘A wide-dynamic-range CMOS image sensor（CIS） based on synthesis of a long-time and a short-time exposure signal in the floating diffusion（FD） of a five-transistor active pixel is proposed.With optimized pixel operation,the response curve is compressed and a wide dynamic range image is obtained.A prototype wide-dynamic-range CMOS image sensor was developed with a 0.18μm CIS process.With the double exposure time 2.4 ms and 70 ns,the dynamic range of the proposed sensor is 80 dB with 30 frames per second（fps）.The proposed CMOS image sensor meets the demands of applications in security surveillance systems.
文摘Many methods have been suggested to reduce dispersion in optical fiber communication. Among these methods, chirped fiber grating (CFG) is a promising scheme. This paper describes a linearly chirped fiber grating with 95% reflectivity and 0.3 nm bandwidth written using a double exposure method with a uniform phase mask. The CFG resonant wavelength is 1554.5 nm and dispersion is 1700 ps/nm. Dispersion compensation in a 10-Gb/s optical transmission system has been demonstrated using this chirped fiber grating. The power penalty induced by the dispersion compensation after 180-km transmission is 1 dB. This is the first report describing dispersion compensation of 180 km at 10-Gb/s optical transmission now-return to zero (NRZ) system in China.
