Nonlinear optical properties of pulsed-laser-deposited GeAsSe films and simulation of a nonlinear directional coupler switch

Abstract

Linear and nonlinear optical properties of Ge33As12Se55 pulsed-laser-deposited (PLD) films are presented. The effect of exposure on these films is investigated in some detail. The PLD films showed photobleaching as a result of exposure to 610-nm laser light. Degenerate four-wave mixing and Z-scan techniques were used to obtain the nonlinear refractive index and absorption coefficient of germanium arsenic selenide films. Ge33As12Se55 films are highly nonlinear, and their measured n_2 value was 2.2 × 10^−13cm²/W. The suitability of Ge33As12Se55 PLD films for ultrafast all-optical switching is also discussed. We designed and simulated a nonlinear directional coupler switch that can be made in PLD films.