Abstract
The field of laser picosecond acoustics has thrived owing to the ease of detection of propagating picosecond acoustic pulses through changes in optical reflectance. Reflectance changes are caused by the inhomogeneous modulation of the refractive index by the propagating elastic strain through the photoelastic effect and also by the associated induced motion of the surface and interfaces. In this paper we present a general formula for calculating the reflectance change based on a rigorous one-dimensional treatment of the perturbation in optical properties of arbitrary multilayer structures. The theory is applied to the quantitative analysis of data obtained by laser picosecond acoustics for a SiO 2–Cr double-layer film on a fused silica substrate. The analysis allows the discrimination of the photoelastic contribution and the surface or interface motion contribution to the experimental reflectance variation.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
