Single step zero-thermal-expansion temperature measurement of optical reference cavities
Zhiyuan Wang, Yanxia Ye, Jialu Chang, Jingxuan Zhang, Yunlong Sun, Leilei He, Qiyue Wu, Z. H. Lu, Jie Zhang
Abstract
level. The laser reference cavity is typically nested in a multi-layer thermal enclosure to increase vacuum thermal time constant and thermally controlled at the zero-thermal-expansion temperature to reduce the external temperature fluctuation effect. It is rather time consuming to accurately determine the zero-thermal-expansion temperature for a large thermal time constant system. Here we develop a fast method for measuring the zero-thermal-expansion temperature of the cavity by relying on just one single temperature scan. We first develop a theoretical model to predict the performance of the laser locked to the reference cavity, and then construct an evaluation system for verification of the model. The zero-thermal-expansion temperature of a 30-cm cavity is measured to be 4.3±0.5 °C. The fast and high precision method for determining the zero-thermal-expansion temperature will be valuable in improving long-term frequency stabilities of cavity stabilized lasers.