Bragg reflectors for measuring optical parameters of layers of metamorphic InAlGaAs/GaAs heterostructures.

Spectroscopic reflectometry was used within 700-1600 nm wavelength range to investigate dispersion curves for In0.06 Al0.94 As, In0.06 Al0.1 Ga0.84 As, and In0.06 Ga0.94 As layers, which constituted the purpose-made metamorphic InAlGaAs/GaAs Bragg reflector (BR). The procedure for determining the refractive index based on analyzing variations in cross-correlation coefficient obtained for reflection coefficient calculated and experimental dependences is presented. The sensitivity of the proposed method for variations in refractive index was investigated depending on the number of BR periods, the extinction coefficient of the layers of BR, and the wavelength range with respect to the main reflection maximum.