微弱光信号瞬态布里渊放大器的最佳工作点  

Optimal working point of a Brillouin amplifier for a weak input signal in the transient regime

作　　者：高玮[1,2] 吕志伟[3] 何伟明[3] 

机构地区：[1]哈尔滨理工大学,工程电介质及其应用教育部重点实验室,哈尔滨150080 [2]哈尔滨理工大学应用科学学院光信息科学与技术系,哈尔滨150080 [3]哈尔滨工业大学光电子技术研究所,哈尔滨150080

出　　处：《物理学报》2012年第20期276-281,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:61078004);中国博士后基金(批准号:20100481017);黑龙江省教育厅科学技术研究计划(批准号:12511114)资助的课题~~

摘　　要：为提高瞬态布里渊放大器的工作性能,利用包含噪声的瞬态布里渊放大理论模型数值模拟了放大器的信噪比、灵敏度、能量转换效率及信号放大率随指数增益系数G的变化规律,获得了放大器的最佳工作点G_(opt.)采用倍频Nd:YAG脉冲激光器,以CS_2和FC-72为非线性介质进行了实验验证.结果表明,抽运光脉冲相对于信号光脉冲延迟脉冲宽度的一半进入放大器时,G_(opt)可设在介质受激布里渊散射阈值增益G_(th)之上.对于共线型布里渊放大结构,G_(opt)为Gth的1.1—1.3倍;对于非共线型结构,G_(opt)可超过G_(th)1.3倍,实现近饱和放大.In order to improve the working performances of a transient Brillouin amplifier, the dependences of the signal-noise-ratio, sensi- tivity, energy extraction efficiency and signal amplification factor on exponential gain G are numerically studied based on the theoretical model of transient Brillouin amplification including distributed noise, and an optimal working point of a Brillouin amplifier is obtained. Experimental verifications are performed by choosing CS2 and FC-72 as nonlinear media. A frequency-doubled Nd ： YAG pulse laser is used. Results show that when the pump pulse lags behind the Stokes signal pulse by an amount of time equal to half the pulse width, Gopt can be set to be above the SBS threshold exponential gain Gth. For a collinear Brillouin amplifier, Gopt is 1.1--1.3 times Gth; while for a non-collinear structure, Gopt can be set to be over 1.3 times Gth. Nearly saturated amplification is achieved.

关 键 词：瞬态布里渊放大器 最佳工作点 受激布里渊散射阈值增益 延迟时间 

分 类 号：TN722[电子电信—电路与系统]