Resonant cavity LEDs at 655 and 880 nm wavelengths

Monolithic top-emitting resonant cavity light-emitting diodes (RCLEDs) have been fabricated by solid-source MBE. The RCLEDs in the 650-nm range, with modulation bandwidths exceeding 180 MHz, are possible low-cost transmitter candidates for systems using plastic optical fibers (POFs), such as IEEE-1394 at 100 Mb/s and 200 Mb/s and ATM at 155 Mb/s. Modulation bandwidth of >120 MHz and light power of 2 mW (cw) have been achieved for diameter 84-mu m devices driven at a 40 mA current. Accelerated ageing tests for 27,500 device-hours indicate no degradation in output power. A variation in device temperature significantly modifies the far-field pattern and thus the fibre coupling efficiency, due to a cavity detuning effect. The effects of detuning and the temperature and bias dependencies of the devices are investigated. The 880-nm RCLEDs have a maximum output power of 25 mW. Applications include open-air optical communication systems, collision avoidance and measurement systems.