Micro damage measurement of active ring resonator optics using digital holographic microscopy
摘要
In this study, we present a non-destructive experimental platform employing total internal reflection digital holographic microscopy to precisely assess the degradation of optics used in active ring resonators, a crucial component in advanced navigation systems like Ring Laser Gyroscopes. Refractive optics-based ring resonators typically rely on high-quality fused silica optics due to its exceptional optical and mechanical properties. The developed method characterizes degradation through spatial distribution of refractive index changes in the affected regions, comparing them with undamaged areas. In total internal reflection mode, the reflected phase is influenced by the incident angle at the TIR interface and the refractive indices of the interacting media. The experimental setup integrates a custom-designed precision Right-Angle Prism made from Astrositall material, combined with an index-matching liquid at the total internal reflection interface for seamless contact with the optics, enabling single-shot measurements. Our findings on a damaged sample reveal a degradation pattern with a near-Gaussian profile, showing a maximum refractive index increase of approximately