Fabrication and characterization of high-quality-factor silicon nitride nanobeam cavities

We present the fabrication and characterization of high-quality-factor (Q) Si(3)N(4) photonic crystal nanobeam cavities at visible wavelengths for coupling to nitrogen-vacancy centers in a cavity QED system. Confocal microphotoluminescence analysis of the nanobeam cavities demonstrates quality factors up to Q similar to 55,000, which are limited by the resolution of our grating spectrometer. This is a 1-order-of-magnitude improvement over previous SiN(x) cavities at this important wavelength range. We also demonstrate coarse tuning of cavity resonances across 600-700 nm by lithographically scaling the size of fabricated devices. (C) 2011 Optical Society of America