The temperature of the f - p cavity is accurately controlled by a set of thermoelectric cooler ( tec ) modules attached on the body of the cavity and the electronic feed - back circuit . we found that the long - term unidirectional frequency shift of the output laser resulting from the slow increase of the cavity length under the effect of the temperature integration on the cavity body is essentially eliminated 因此，往往有多台f ? p腔出现在同一个实验装置中本文利用珀耳帖元件，对稳频系统中作为频率参考标准的fabry ? perot干涉仪进行精密控温，并利用f - p腔的透射特性，对自制的全固化单频nd ： yvo _ 4激光器稳频。
