title: Phenomenological model analysis for semiconductor optical amplifiers and application to time-domain digital polarization encoding.
abstract: We propose and demonstrate that semiconductor optical amplifiers (SOAs) for each wavelength of the input can be described by a lumped-elements sequence of a partly linear polarizer and a retarder followed by a polarization-independent amplifier, and further obtain two necessary conditions for the valuable orthogonal polarization rotation (OPR), which will be instructive for SOA-based all-optical signal processing. Subsequently we implement photoinduced OPR by controlling an approximately 2.5 mW pump laser and find the optimal pump wavelength should be an approximately 0.4 nm interval around the central wavelength of the probe laser. Therefore we propose a time-domain digital polarization encoding scheme based on photoinduced OPR with cross-gain modulation in a SOA and perform it well in a 15 km single-mode-fiber system at 2.5 Gbits/s, which is applicable to optical-power-equalized fiber communication.
authors.affiliation: Institute of Optical Information, Beijing Jiaotong University, Beijing, China. lzyyh2007@yahoo.com.cn
authors.forename: Zhengyong
authors.initials: Z
authors.lastname: Li
authors.forename: Chongqing
authors.initials: C
authors.lastname: Wu