半导体抽运Nd:YAG激光器强度噪声抑制的研究

为了降低半导体抽运固体激光器的弛豫振荡噪声,提高其输出功率的稳定性,采用光电负反馈的方法来抑制半导体抽运的固体激光器的强度噪声,并对激光器强度噪声的理论特性进行了分析。根据理论分析结果设计了比例-积分-微分反馈控制电路,通过运用该反馈电路对激光器进行强度噪声抑制实验,得到了比较理想的实验数据,即当抽运功率为700mW、弛豫振荡峰频率为300kHz时,弛豫振荡峰值处和低频区域强度噪声分别降低了45dB和15dB;当抽运功率为550mW、弛豫振荡峰值为250kHz时,弛豫振荡峰值处和低频区域强度噪声分别降低了40dB和10dB。结果表明,该反馈控制电路能够有效地降低半导体抽运固体激光器的强度噪声,提高激光器输出功率的稳定性。

Research of intensity noise suppression in laser diode pumped Nd:YAG lasers

In order to reduce the relaxation oscillation noise of a diode pumped solid-state laser and improve its stability of output power , the intensity noise was suppressed by means of optoelectronic negative feedback .Theoretical characteristics of laser intensity noise were analyzed . According to the results of theoretical analysis , a proportion-integration-differention ( PID ) feedback control circuit was designed .By carrying out feedback circuit to suppress the laser intensity noise , ideal experimental data were obtained .When pumped power is 700mW, peak frequency of relaxation oscillation is 300kHz, intensity noise at relaxation oscillation peak and low frequency decreases to 45dB and 15dB respectively.When pumped power is 550mW, relaxation oscillation peak frequency is 250kHz, intensity noise at relaxation oscillation peak and low frequency decreases to 40dB and 10dB respectively.The results shows that the feedback control circuit can effectively reduce intensity noise of a diode pumped solid state laser and improve the stability of laser output power .