Fabrication of Micromirror Templates Using a Focused CO2 Laser

Micromirrors are an important component in quantum optics, for example in Fabry-Perot microcavities, where light can be recirculated within small volumes. Recently, a CO2 laser method has been demonstrated as a way to fabricate micromirror templates with an exceptionally high surface quality. However, these templates typically vary in size significantly, which is undesirable in many applications, for example when arrays are needed. Here we address this problem by implementing a feedback method, which uses the light emitted by the sample during the ablation process. By measuring the intensity of the light emitted and correcting, in real time, the laser intensity, we can control the feature size to be less than 5 percent.