Self-frequency-conversion nanowire lasers

摘要

Semiconductor nanowires(NWs)could simultaneously provide gain medium and optical cavity for performing nanoscale lasers with easy integration,ultracompact footprint,and low energy consumption.Here,we report Ⅲ-Ⅴsemiconductor NW lasers can also be used for self-frequency conversion to extend their output wavelengths,as a result of their non-centrosymmetric crystal structure and strongly localized optical field in the NWs.From a GaAs/In0.16Ga0.84As core/shell NW lasing at 1016 nm,an extra visible laser output at 508 nm is obtained via the process of second-harmonic generation,as confirmed by the far-field polarization dependence measurements and numerical modeling.From another NW laser with a larger diameter which supports multiple fundamental lasing wavelengths,multiple self-frequency-conversion lasing modes are observed due to second-harmonic generation and sum-frequency generation.The demonstrated self-frequency conversion of NW lasers opens an avenue for extending the working wavelengths of nanoscale lasers,even to the deep ultraviolet and THz range.