Microwave characterization of Purcell enhancement in a microcavity laser

A sensitive microwave method is described to study the optical frequency response of a microcavity laser, demonstrating that a quantum-well vertical cavity surface-emitting laser (∼3 μm aperture, ITH=180 μA) can exhibit almost single mode operation (nearly threshold free), and an electron-hole spontaneous lifetime Purcell enhancement of 2.08 times. The microwavemeasurement method employing electrical-to-optical conversion, and distinct separation of electrical input and optical output, is more revealing than photoluminescence decay experiments (and the inconvenient overlap of optical input and output).