毫米级氟化钙盘腔的加工与测试

Fabrication and test of millimeter-size CaF_2 disk resonator

回音壁模式(Whispering Gallery Mode,WGM)的光学谐振腔作为光学研究的重要工具具有广泛的应用前景。以超纯单晶氟化钙为材料加工了直径为5 mm,厚度为1 mm的Ca F2盘型腔,并用化学机械抛光法对其进行了光学抛光,得到了粗糙度为纳米级别的CaF2盘型腔。搭建盘腔与锥形光纤的耦合测试平台测试所加工盘型腔的光学性能,测得在波长为1 550 nm时所加工的盘型腔的品质因数为2.1×106。对CaF2盘型腔损耗机制进行了理论分析,提出了提高CaF2盘型腔品质因数的方法。

Whispering gallery modes （WGM） optical resonators is an important tool for optical research with broad application prospects. A CaF2 disk resonator was fabricated with ultra-pure single crystal of calcium fluoride characterized by the diameter of 5 mm and thickness of 1 mm. The CaF2 disk resonator was polished with chemical mechanical polishing method and nanometer-scale roughness was achieved. The coupling test platform of disk resonator and tapered fiber was set up to test the optical properties of the resonator. The test results showed that CaF2 optical resonator characterized by the quality factor Q= 2.1×10^6 at λ=1 550 nm. The loss mechanisms of the resonator was analyzed and the method to improve quality factor of the CaF2 resonator was proposed.