Sample integrated laser for optical thickness measurement using single-shot interferometry

We present a method for measuring the optical thickness of a high-finesse Fabry-Perot etalon using single-shot interferometry. By integrating the sample etalon into the laser cavity, a new light source, to our knowledge, is demonstrated that improves the sensitivity limitation of the rear-surface reflection signal. Comparative results with the conventional single-shot approach are also discussed. The light source achieved a sweep time of 49 µs and a tuning range of ∼1.65THz. The experimental results were obtained using a customized etalon with an approximate optical thickness of 730 µm, and the average optical thickness was measured as (7.0±0.1)×10²µm.