基于非对称热结构的激光热稳频系统

Thermally compensated laser frequency stabilization system based on asymmetric thermal structure

针对目前热稳频激光器抗干扰能力差的问题,研制了一种基于非对称热结构的激光热稳频系统。该系统采用不同热传导材料建立具有多个连续热传导层的热结构,其中电热控制层和干扰吸收层被有限导热层隔离并呈不对称的热传导特性。由于有限导热层的隔离作用,电热控制和环境干扰对激光管的热作用速度分别取决于电热控制层和干扰吸收层的热惯性大小。结构参数设计中使电热控制层的热惯性远小于干扰吸收层,则可在保证电热控制效率的同时降低环境干扰的作用速度,从而提高稳频系统的抗干扰性能。最后,建立基于非对称热结构的纵向塞曼激光热稳频系统,对其抗干扰特性进行验证。实验结果表明:在普通实验室条件下稳频系统的频率稳定度优于1.8×10-10,而在1m/s的持续气流扰动下其频率波动<1.5×10-9。

In order to improve the anti-interference ability of frequency stabilized lasers, the frequency stabilized laser based on asymmetric thermal structure was developed. The asymmetric thermal structure consisted of several continuous thermal transfer layers with different heat transfer coefficients, the electric heater control layer and the interference absorbing layer were isolated by the limited transfer layer, which characterized asymmertric thermal transfer. Through the heat isolation effect of the limited thermal transfer layer in the structure, the laser tube had asymmetric thermal inertia to electric heater control and environment interference, and its thermal effect speed was decided by the thermal inertia. Finally, longitudinal Zeeman frequency stabilized laser system based on asymmetric thermal structure was estabished, its anti-interference performence was verified.Experimental results indicate that frequency stability of the laser based on inertia isolation can be superior to 1.5×10^-10 in ordinary lab condition, while it is less than 1.5×10^-9 where the speed of airflow is 1 m/s.