Photoelastic Effect and Optimal Waveguide Structure in InGaAsP/InP Double Heterostructures

Stress field profiles and dielectric constant variations in InGaAsP/InP double heterostructures caused by a 110 nm-thick W_0.95Ni_0.05 metal thin film strain stripe are calculated. Both theoretical and experimental results demonstrate the form of photoelastic waveguide structure in the InGaAsP/InP double heterostructures. For a 4μm-width W_0.95Ni_0.05 thin film strain stripe, the difference between dielectric constants of waveguide at the center and the edge of stripe is 9 \times 10^-2 - 2 x 10^-2 in the depth range from 0.2 to 2μm of the semiconductor. At a given depth, the width of strain stripe for optimal waveguide structure is determined. The maximal change of dielectric constant for the waveguide is an inverse proportion of the depth.