Broadly-tunable resonant-cavity light-emitting diode

Microelectromechanical wavelength tuning is demonstrated for the first time in a resonant-cavity light-emitting diode. The device utilizes a deformable-membrane top mirror suspended by an air gap above a diode-active region and bottom mirror. Applied membrane-substrate bias produces an electrostatic force which reduces the air-gap thickness, and therefore, the resonant wavelength. We report broad tunability of nearly 40 nm and spectral linewidths as narrow as 1.9 nm (2.6 meV) for operation near 950 nm