LASER-FABRICATED LOW-LOSS SINGLE-MODE WAVE-GUIDING DEVICES IN GAAS

We have used a maskless laser etching technique to fabricate novel waveguides and waveguiding structures directly into the surface of GaAs/AlGaAs heterostructures. The modal and loss properties of these groove-defined structures have been measured as a function of waveguide geometry, and low-loss single-mode waveguides have been produced. Using the technique, we have fabricated various passive optical devices in a single processing step. Waveguide bend and branch losses have been measured and are comparable to those in conventionally fabricated devices. Experimental results are described by simple theoretical models. The technique is attractive as a prototyping tool for developing and testing new integrated optic circuits.