Multi-Quantum Well Lateral-Field-Effect Electro-Refraction

Band gap resonant optical non-linearities in III-V compound semiconductor materials provide the basis for novel components, allowing advances in optical signal processing. Of particular interest are temporal and spatial light modulators, which find applications in optical interconnects, optical computing, and logic circuits. Spire will characterize an advanced GaAs multi-quantum well structure which will exhibit the Lateral-Electric-Field-Induced-Refraction (LEFIR) effect. The lightwave propogates transverse to the stack of grown layers, while the electric field, applied laterally due to the removal of a two-dimensional electron gas supplied by planar doping, induces changes in the refractive index of the active region containing the quantum wells. The transmissive modes are shifted in wavelength when the effective refractive index of the active region is altered by the applied field, modulating intensity. Without mirrors, the device can shift the phase of incident light. EFIR modulators can be extended into two-dimensional arrays with applications as spatial light modulators.