[8p-B12-1~6] 3.7 Optical measurement, instrumentation, and sensor

4:00 PM - 4:15 PM JST(7:00 AM - 7:15 AM UTC)

[8p-B12-1] Proposal of a method for evaluating complex photoelastic constants of opaque thin films

〇Motonobu Tomoda¹, Osamu Matsuda², Oliver B. Wright^2,3 (1.Oita Univ., 2.Hokkaido Univ., 3.Univ. Osaka)

Keywords:

interferometry,spectral analysis,photoelasticity

Photoelastic constants are important material parameters that relate strain to optical response, but measurements for opaque thin films remain limited. In this work, we propose a method for evaluating the complex photoelastic constants of opaque thin films using spectral analysis of picosecond ultrasonic echoes. By utilizing the surface-displacement and photoelastic contributions contained in the complex reflectivity change, together with the condition that the acoustic strain profile is a real-valued function, the complex photoelastic constants can be determined. Numerical validation results of the proposed method will be presented.