中文摘要：

应用Mueller矩阵的极分解，对半导体光放大器（SOA）的偏振旋转效应进行了精确的实验分析。SOA的Mueller矩阵可以分解为双折射MR、偏振相关增益MD、和去偏振MΔ三项，其中MR决定偏振旋转（PR）的角度θ，并可由公式θ=arccos[Tr（Mn）／2—1]计算。实验采用计算机控制的测量系统得到SOA的Mueller矩阵。分析结果表明，SOA的自发辐射会降低输入信号的偏振度；PR角只与输入波长成线性关系而与注入电流及输入光功率均为非线性关系。实验进一步研究了抽运探测方案中的光诱导偏振旋转（PPR）和交叉增益调制效应，发现输出光的PR角及光功率与控制光强度非线性相关，而且控制光大约为3．5mw时即可产生正交偏振旋转。由此实现了一种光控的高速偏振开关，此开关响应时间小于300ps，可用于Gb／s级的高速数据通信。

英文摘要：

This letter introduced the Mueller matrix method （MMM） with polar decomposition to precisely analyze the PR activities of semiconductor optical amplifiers （SOAs）, where the SOA is described by a Mueller matrix M which is decomposed to a diattenuator MD, a retarder MR, and a depolarizer MΔ. The polarization rotation （PR） is determined by the retarder matrix MR, and the rotation angle θ can be calculated by θ= arccos[Tr （MR）/2- 1]. It employed a computer-controlled measurement system to obtain Mueller matrix M of the SOA. Experimental results showed the amplified spontaneous emission noise in SOAs will decrease the degree of polarization of optical signal. And the PR angle was linear to input optical wavelength, while it was nonlinear to injected current and optical power. Moreover we apply a pump-probe scheme to investigate the photoinduced PR and cross-gain modulation effects in the SOA, and we found both PR angle and output power were nonlinear to the controlling optical power while obtain the orthogonal PR by controlling of a - 3.5 mW laser. Based on above results we realized a high-speed polarization switching with response time less than 300 ps, which is applicable to high-speed data communication at Gb/s.