Semiconductor nano-cavities with a very small mode volume, can lead to significant enhancement of spontaneous emission rates, due to the Purcell effect. Despite the very small gain medium volume, lasing action has been demonstrated in 2D photonic crystal defect cavities. Here we present the fabrication procedure and Q measurements of photonic crystal defect cavities in InGaP. The fabrication technique involves standard e-beam lithography, a pattern transfer SiO2 mask and CAIBE etching of the periodic structure into the semiconductor material.
The Q of such cavities can be very high and we will present our experimental results on the measurement of high-Q cavities. Different techniques are used to estimate the Q value, including transmission/reflection of light with energy below the semiconductor absorption edge and spontaneous emission enhancement at the cavity resonant frequency.