Planar InGaAsP/InP photoelastic waveguides with low propagation loss

Abstract Planar, low-loss double heterostructure InGaAsP/InP waveguides have been fabricated employing the photoelastic effect induced by metal stressor stripes deposited on the surface of the semiconductor structure. Single-mode guiding is observed in regions beneath a window stripe in an otherwise continuous Ni film deposited on the waveguide structure (type A), or in regions beneath a narrow stripe of W film sputtered on the waveguide structure (type B). The lowest measured propagation loss is 2.0 dB/cm for the type A and 3.5 dB/cm for type B waveguides at the 1.52 μm optical wavelength. The lateral waveguiding depends on both the annealing temperature and the semiconductor layer structure beneath the metal. Both types of waveguides on InP/InGaAs/InP maintain low loss, single mode guiding for temperature ≤ 300°C. Preliminary planar photoelastic optical devices such as splitters and couplers have also been demonstrated.