Ultraviolet amplified spontaneous emission from zinc oxide ridge waveguides on silicon substrate

Device-quality ZnO thin films were deposited on lattice-mismatched silicon substrate by the FCVA technique. High intensity UV ASE was observed from the devices at room temperature. A stable fundamental TE mode was maintained inside the ridge waveguide at high pump intensity, and the corresponding maximum net optical gain was found to be 120 cm-1at 1.9 MW/cm2pump intensity. This high pump intensity indicate that the ZnO thin films on silicon substrate can withstand catastrophic optical damage at very high pump (lasing) intensities, so that they are a durable active medium to realize lasers.