Thick transparent semiconductor substrate heterojunction acoustic charge transport multiple quantum well spatial light modulator

摘要

A one-dimensional or two-dimensional transmission mode spatial light modulator (SLM) includes one or more heterojunction acoustic charge transport (HACT) channels 18 with surrounding layers 16,20 vertically adjacent to a multiple quantum well (MQW) region 14, grown above a thick semiconductor substrate 10 thick enough to allow a surface acoustic wave (SAW) to propagate and transparent to the incident light 40. The SAW is injected by a transducer 24, charge is carried to and from the HACT channel 18 by electrodes 32,34,36, and light 40 is applied to a surface 44 perpendicular to the MQW region 14. Each charge packet 19 in the HACT channel 18 invokes an electric field 52 within the MQW region 14 which determines the optical absorption and index-of-refraction thereof, thereby determining the intensity and/or phase of each output light beam 45. Light modulation is achieved by modulating the amount of charge injected.