兰姆凹陷稳频工作点自动识别技术

Auto-Lamb Dip Frequency Stabilized Laser

兰姆凹陷稳频激光器中,在压电陶瓷的调整范围内会周期性出现多个兰姆凹陷曲线波形,不同兰姆凹陷曲线的切换点处激光器的输出功率为极小值,与兰姆凹陷点的特征相同。制造工艺无法保证激光器切换点处的输出功率极小值一定大于或小于凹陷点处的功率极小值,因此无法通过激光输出功率及调制输出信号的相位关系直接区分切换点和凹陷点。经过分析兰姆凹陷现象的形成原因、推导兰姆凹陷曲线表达式、分析兰姆凹陷线型特点,发现兰姆凹陷曲线在凹陷区域两侧各有一波形拐点,在拐点附近,一次导数曲线会发生跳变,而在凹陷区域则无此现象。这一特点可以作为软件自动识别切换点和凹陷点的判据,实现自动兰姆凹陷稳频。

In the Lamp Dip frequency stabilized laser,there are several Lamp Dip figures in the adjustment range of PZT. The switch points of different Lamp Dip figures are dip points,just as the Lamp Dip points. And we can not eliminate those dip points from real Lamp Dip points by the laser power or the phase of modulation signals. After analyzing the reason of Lamp Dip phenomenon,deriving the formula of Lamp Dip,and discussing the features of Lamp Dip curve,we found that there is an inflexion point on each side of Lamp Dip curve,and the differential curve of Lamp Dip has a jumping at those points. This character can be used by embedded system to distinguish the switch point and the Lamp Dip point.