Temperature dependencies of the refractive index for Al-Ga-In-As metamorphic layers.

Abstract

Temperature dependencies of the refractive indices, n, for InxGa1-xAs and InxAl1-xAs metamorphic layers with x=0.06-0.25 have been determined. For this purpose, we performed variable-temperature (80 to 400 K) measurements of the specular reflection coefficient using custom distributed-Bragg-reflector structures in the spectral range from 0.8 µm to 2.2 µm. All the compositions exhibited a nearly linear temperature dependence of n. For InxGa1-xAs, the temperature coefficient (dn/dT) increases from 2.0⋅10-4K-1 for x=0.06 to 4.5⋅10-4K-1 at x=0.25. In turn, the temperature coefficient of the InxAl1-xAs refractive index stays at the level of (1.7-2.0)⋅10-4K-1 at the considered indium contents.