电磁感应涡流加热稳频系统设计

The system design of using electro-magnetic induction heating to perform the laser frequency stabilized

针对在线测量需要强抗干扰能力以及高速测量的需要,利用新式He-Ne激光器采用金属管颈的特点,采用电磁感应涡流加热方法实现热稳频。该方法改变的谐振腔部分(激光管管颈)不被放电管外的玻璃管包围,所以散热条件好,其热变形不受约束,使系统具有预热时间短、响应速度快、抗干扰能力强、频率稳定性好等优点。经实验证明,此方法使激光器输出激光频率稳定度在恒温条件为时可达10-9,在有强冷、热气流吹拂时,也能保证不低于10-7的频率稳定度。同时双频激光频差大于500 MHz,使测量速度进一步提高。

In order to meet the requirements of online measurement in high anti-interference ability and the needs of the high-speed measurements, this article provides a new system which used induction heating to perform frequency-stabilized of double longitude modes laser. The neck of laser tube based on this method is exposed in air with very good thermal dispersion conditions, so the system has a short warm-up time, rapid response speed, strong anti-interference ability and good frequency stability. Experiments have demonstrated that, under the condition of constant tempera^tre, the frequency error of double-frequency laser interferometer with two longitudinal modes could be controlled within 10-9. Even with conditions such as with cool or hot air blowing, it can still be kept within 10-7. While its modal difference （i.e. carrier frequency） is large than 500 MHz, the measurement speed is further improved.