Resonant, dispersive optical tuning in an epitaxial (Al,Ga)As Fabry–Perot étalon

We report optical tuning (an optically induced shift of the transmittance peak) of an epitaxial Fabry–Perot étalon comprising AlAs/AlGaAs quarter-wave high reflectors surrounding a GaAs/AlGaAs multiple quantum well spacer layer. The reflectors and spacer were produced in a single growth process by using molecular beam epitaxy. Low-power cw reflection and trasmittance spectra as well as higher power pulsed trasmittance spectra were measured at room temperature. A very sharp (∼20 Å full width at half-maximum) Fabry–Perot transmittance peak was observed near the resonant exciton wavelength (8500 Å) at room temperature. The tuning of this transmittance mode under pulsed optical excitation is as large as 27 Å. These results indicate that very large on/off switching ratios (∼10:1) can be achieved with these structures.