CW substrate-free metal-cavity surface microemitters at 300 K

In this paper substrate-free metal-cavity surface microemitters are demonstrated. The optical cavity is formed by a metal reflector, metal-surrounded sidewall and n-doped distributed-Bragg reflector, which provides optical feedback and carrier injection. We describe a simple design principle with the modal properties modified by geometry and metal-insulator cladding. Both resonant cavity light-emitting diodes (1.85 mu m diameter and 0.6 mu m height) and lasers (2.0 mu m diameter and 2.5 mu m height) are successfully fabricated and characterized. These two types of devices operate at room temperature under continuous-wave (CW) operation. Since the devices are substrate-free, they can be bonded to any substrates. From the threshold currents of the lasers, we obtain a high characteristic temperature of 425 K in the range of 10-27 degrees C. We also discuss a general approach to improve the diffraction from small-aperture devices.