Influence of slanted guiding layer on reflection curve and sensitivity for air-gap displacement sensor

摘要

We investigate the influence of slanted guiding layer on reflection curves and sensitivity for air-gap optical waveguide structures. The theoretical analysis method is based on the interference between multiple light beams in the slanted guiding layer. The main relative characteristics of reflection curves and sensitivity as a function of inclination angle of slanted air-gap have been demonstrated in detail for symmetrical metal-cladding waveguide (SMCW) and Fabry-Pérot (FP) system. Results show that the sensitivity of SMCW with millimeter air-gap is more influenced by inclination angle than that of FP system. When inclination angle is larger than 10 μrad, the reflection curve shows serious distortion for all waveguide configurations.