W_0.95Ni_0.55 Compressive Strain Thin Film Stripe Window Induced Photoelastic Waveguide Structure in InGaAsP/InP Double Heterostructure

We calculate profiles of strain field and dielectric constant variations in InGaAsP/InP double heterostructures beneath a 110-nm-thick W_0.95Ni_0.55 compressive strain thin-film stripe window. The theoretical results demonstrate the form of the photoelastic waveguide structure in the InGaAsP/InP double heterostructures. The strength of the photoelastic waveguide structure caused by a 20-μm-wide W_0.95Ni_0.55 compressive strain thin film stripe window is 2.9 x 10^-2-0.7 x 10^-2 in the depth range from 1μm to 2μm of the InGaAsP/InP double heterostructure. The turning point between waveguide and antiwaveguide is also determined. The theoretical results have demonstrated that the photoelastic waveguide structure may confine well the lateral light of the InGaAsP/InP double heterostructure when the width of the W_0.95Ni_0.55 compressive strain thin-film stripe window is 5 times greater or 0.93 times smaller than the depth of the photoelastic waveguide structure.