高精度激光信号源的设计实现

Design and Implementation of High-precision Laser Signal Source

随着激光信号在激光测量、激光通信,光学传感等领域中的应用,半导体激光器的调制成为满足激光信号在各领域中应用的低成本且高效的方法。提出了一种基于激光器的直接调制原理的高精度激光器信号源,实现输出激光信号在频率、相位和幅值上独立可调。输出激光信号的形式为正弦信号,其频率为10 kHz~20 MHz。该系统调制信号主要由AD9959提供,由AD5791提供高精度偏置信号,通过压控电流源为半导体激光器提供稳定的驱动电流信号,以保证输出激光信号的稳定。实验结果表明,该调制系统能够有效输出激光信号,且激光幅值、频率、相位均独立可调,调制深度优于0.85,可实现10 kHz~20 MHz频率的光信号调制;对光电转换后的激光信号曲线拟合,得到频率误差可达190 ppm,残余误差为-2.168×10^(-2) V。能够实现高精度、大带宽幅值范围的激光信号调制,输出激光信号质量能够满足激光测量等领域的需求。

A high-precision laser signal source based on the principle of laser direct modulation is proposed.The output laser signal can be adjusted independently in frequency,phase and amplitude.The output laser signal is in the form of a sinusoidal signal and its frequency ranges from 10 kHz to 20 MHz.The modulation signal of the system is mainly provided by AD9959,and the high-precision bias signal is provided by AD5791.The stable driving current signal is provided for the semiconductor laser through the voltage controlled current source to ensure the stability of the output laser signal.Experimental results show that the modulation system can effectively output the laser signal,and the laser amplitude,frequency and phase are independently adjustable,the modulation depth is better than 0.85,and the frequency of 10 kHz~20 MHz can be realized.The curve fitting of the laser signal after photo-electric conversion shows that the frequency error can reach 190 ppm,and the residual error is-2.168×10^(-2)V.