基于全光纤以及主控振荡功率放大器,设计并搭建了一套扫频范围为125~165 MHz的拍频信号的放大系统。并设计了一套基于1064 nm的Nd:YAG单块非平面环形腔激光器作为单频种子源。通过声光移频的方式将1064 nm单频激光分成中心频差为150 MHz的两束激光进行拍频。双频激光初始功率为50 mW,通过放大系统将双频功率放大到10 W。通过实验及分析得出两束频差为150 MHz的激光功率比率在放大之后保持不变,且经过放大的激光信号中,拍频信号所占的功率成分可以通过调节双频功率比以及单臂分量的偏正态来获得最大输出。同时对拍频信号的信噪比及线宽进行了实验分析。

The output power of dual-frequency laser source is usually low that it cannot meet the requirements of measurement of long distance. The amplification of 125-165 MHz sweep beat frequency signal using an all-fiber master oscillator power-amplifier(MOPA)system is demonstrated. A non-planar ring oscillator laser(NPRO)with central wavelength of 1064 nm is designed as the single frequency laser seed. An acoustic modulator with central frequency of 150 MHz is used to produce 50 mW dual frequency signal with combination of master and diffraction beam by 1064 nm frequency shifting. The power of dual frequency laser is boosted up to 10 W. The beat signal can sweep from 125 MHz to 165 MHz. The relative magnitude of the two single-frequency signals is maintained in the amplification process and the maximal output power of beat signal can be realized by polarization controlling. The signal noise rate and bandwidth of beat signal are also experimented and analyzed.