Advanced Structures For Integrated Optics Realized With Shadow Masked Growth
The fabrication of integrated optic devices in semiconductor materials requires advanced processing techniques. In this paper, we propose the shadow masked growth (SMG) as an alternative to other techniques such as multi-step etching, mass transport, selective growth, shadow masked etching, etc. Two applications will be described: refractive lenses and tapered structures. The lenses can easily be integrated with LEDs or vertical cavity substrate-emitting laser diodes, or can be used for the realisation of 3-D microcavities. The tapered structures find interesting applications in optical mode shape transformers (e.g. for improved waveguide fibre coupling) and in bandgap engineering (when using quantum wells).