So far the impact and promise of GaN devices are focused mainly on optoelectronic and microelectronic devices. The blue LEDs and their inventors have been recognized with Nobel prizes, and GaN power transistors are positioned to play a key role in compact energy efficient power electronics.

The exploration of GaN in photonic devices and structures, which seeks to manipulate optical density of states and propagation properties through linear and non-linear optical index engineering, has received much less attention. In this talk we will summarize our effort in making GaN resonators in one, two, and three dimensions. We will review the performance and challenges associated with different fabrication pathways. With the use of a novel electrochemical process, we are able to selectively porosify or electro-polish GaN. The electrochemical process enables unprecedented tuning in the index of refraction, making it possible to create optical confined structures and laser diodes.

The research is supported by US Department of Energy, National Science Foundation, and DARPA.