Multiple quantum well devices for optoelectronics

Semiconductor multiple quantum well(MQW) structures represent a new technology for opto-electronics. These quantum wells, which are extremely thin(∼100Å) layers of a low band-gap semiconductor sandwiched between layers of a higher band-gap semiconductor, have opto-electronic properties greatly enhanced over conventional semiconductors. For example, we have fabricated a 150 µm long optical modulator with an on/off ratio of 10:1, and used it to generate optical impulses less than 100 ps long. This technology is compatible with existing source and detector material systems, and produces devices that are compact, high speed, and suitable for integration.