<title>Resonant cavity light-emitting diodes</title>

Abstract

LEDs are important devices in communications and optical displays. One of the most promising methods of improving the LED comes in the form of Resonant Cavity Light Emitting Diode, or RCLED. A planar microcavity changes the fundamental emission properties of the light emitting material between two planar mirrors. The intensity and spectral purity of emission can be considerably increased over that of a normal LED. We present results for InGaAs/GaAs/AlGaAs optical fiber communications RCLEDs operating at 910nm to 950nm wavelength. These substrate- emitting devices consist of a silver back mirror and contact and a strained layer InGaAs multiple quantum well active region. The output mirror consists of an AlGaAs.GaAs distributed Bragg reflector.These devices exhibit higher intensities on axis at low input current than a perfect internal efficiency conventional LED. The narrower spectral emission coupled into a fiber results in less chromatic dispersion over longer fiber distances. Such devices are also attractive in optical interconnect applications where high efficiency, low power consumption, and high speed are important. We demonstrate that with simple speed up electronics, our RCLEDs can easily communicate at over 622 Mbit/second over short interconnects, and work best at only 5 to 10 mA of input current. Long term measurements indicate no degradation after 14000 hours of room-temperature operation. Mention will be made of the requirements of performance, reliability, and cost for RCLEDs to become viable commercial products.