Measurement and research of cavity loss on squeezed light enhancement mechanism

In the process of generating squeezed light based on parameter down-conversion, the optical cavity loss affects the performance of the squeezed light. In this article, we propose a new method for measuring cavity loss in locking conditions, which has the advantage of being able to accurately measure cavity loss under optical cavity operating conditions. Based on this measurement method, we study the influence of cavity loss on SHG and OPO processes. The experiment results indicate that the reducing the additional cavity loss, such as cavity loss caused by thermal noise can effectively improve the performance of SHG and OPO cavities, and enhance the squeezing degree of squeezed light sources, which will restrict the further improvement of the squeezed light. The research results of this article are of great significance for the generation of high-performance squeezed light and quantum precision sensing based on quantum enhancement.