Abstract

Optical microstructures with high dielectric contrast are of interest to control spontaneous emission, reduce laser thresholds, and increase the binding energies and dipole moments of quantum well excitons. We have fabricated barstool structures where the seat is 2–10 μm in diameter with thicknesses in the 100–500-Å range. These thin films are free standing in air, supported only by an InP pedestal. The pedestals are parallelograms in cross section with dimensions as small as 0.5 μm on a side. Pedestal heights above the InP substrate are in the 2–3-μm range. Composition of the thin films is layered with InGaAs quantum wells between InGaAsP barriers or layers of InGaAs or InGaAsP above. The etch selectivity determines the range of P concentration that can be obtained. Initial results show good photoluminescent efficiencies for the quantum well films with thicknesses in the 500-Å range. Limits on the diameter, thickness, surface quality, and luminescent efficiency are being studied.

© 1991 Optical Society of America