Optical transmission and reflection by a slot with mirror walls in a semiconductor waveguide

The method of expansion of radiation carried by a waveguide mode into plane waves is used to analyze the characteristics of reflection and transmission by a slot with mirror walls in a semiconductor waveguide allowing for the change in the beam profile at interfaces between media. In the case of the Al_xGa_1–xAs–Al_yGa_1–yAs–Al_xGa_1–xAs system such a slot operates as an effective mirror when its width is about 1 μ and depth greater by 0.1 μ than half the waveguide thickness.