Abstract

We discuss our recent experimental and theoretical studies of the dynamics of switching in a bistable system consisting of ZnSe in the form of thin film interference filter^1-3 structures operating in the 500 - 700 nm region of the spectrum. Theoretically, the system can be modelled as an absorbing thin layer of active material (ZnSe) evaporated on a semi-infinite slab of a non-absorbing substrate (glass). The solution of the heat equation can be expressed as a Volterra equation from which an approximate expression for the switch-up time can be derived, namely where w ≡ spot size, D ≡ thermal diffusivity of glass, P_s = threshold power, P₀ ≡ holding power and P₁ = P₀ + power increment (stepwise) at t = 0.

© 1985 Optical Society of America