Molecular-Beam Epitaxially Grown Spatial Light Modulators with Charge-Coupled-Device Addressing

摘要

Molecular-beam epitaxy has been used to grow the first spatial light modulators which combine charge-coupled-device addressing and electroabsorption effects in multiple quantum wells. Charge packets are used to control the electric field across an underlying multiple-quantum-well structure, causing a change in the optical absorption properties of the device. We have demonstrated that the intensity of an optical signal propagating through the device normal to the quantum wells can be significantly modulated. Both 16- and 32-stage one-dimensional and 16x16-stage two-dimensional devices have been fabricated. Devices with GaAs and AlGaAs epitaxial layers have been operated in the 850-nm region and devices with InGaAs and GaAs epitaxial layers have been operated above 900 nm. One-dimensional GaAs/AlGaAs devices exhibit an intensity modulation of 1.45 to 1 at 847 nm and one-dimensional InGaAs/GaAs devices exhibit an intensity modulation of 1.18 to 1 at 965 nm. The large optical modulations achieved by these devices make them excellent candidates for use in optical signal processing and the emerging field of optical computing. (RH)