GaAs/Al y Ga 1-y As waveguide leakage loss reduction by inserting thin AlAs/Al x Ga 1-x As layers into the bottom cladding

Abstract

In this paper, we present the simulation, fabrication and measurement results of GaAs/Al y Ga 1-y As waveguides having a cladding layer nearly 50 percent thinner than the conventional cladding layer thickness, while still achieving an equivalent optical performance. These waveguides are realized by inserting thin layers of Al x Ga 1-x As in the Al y Ga 1-y As bottom cladding layers. The waveguide layers are grown by standard organo-metallic vapor phase epitaxy with the ridge waveguides defined by reactive ion etching. The composition, thickness and the position f the inserted Al x Ga 1-x As layers were optimized so as to maintain the original waveguide performance. The channel waveguide propagation losses are about 1 dB/cm, measured by the Fabry- Perot cavity and the cutback methods. These results were found to be consistent with simulations. The insertion of the thin layers of Al x Ga 1-x As in the specific optimized device performance.