2μm单纵模激光频率短期不稳定度的测量

Short-Term Frequency Instability Measurement of 2 μm Single longitudinal-Mode Laser

利用光纤延时自拍法对固体激光器输出激光频率的短期不稳定度进行了测量。Tm,Ho:YLF微片激光器具有毫瓦量级的单纵模、窄线宽的输出,实验测量了光纤延时长度为500m下,积分时间为2ms,4ms,40ms,100ms的拍频信号。利用自拍频法获得了光纤延时长度为100m,200m,300m,400m,500m,对应的时间延时长度为0.5μs,1μs,1.5μs,2μs,2.5μs下的输出激光的自拍频信号,得出单频激光器的频率不稳定度为1.48kHz/μs。最后对激光频率不稳定度与激光线宽的关系进行了讨论。

The short-term frequency instability of the solid-state laser was measured by using the self-beat of fiber- delay method, The Tm, Ho：YLF microchip laser which was cooled by liquid nitrogen provided with single longitudinal-mode, narrow linewidth output and the power was up to milliwatt. In experiment, at the fixed fiber length of 500 m, self-beat signals of the laser under the integral .time about 2ms, 4ms, 40ms, 100ms were obtained. And under different fiber lengths about 100 m,200 m, 300 m,400 m,500 m, the corresponding time delay is 0.5 μs, 1μs, 1.5μs,2μs,2.5μs, and the self-beat signal of the laser was achieved. The short-term frequency instability of Tm, Ho： YLF microchip laser is 1.48 kHz/~s. Meanwhile the relationship between laser frequency stability and laser linewidth is discussed.