NER: Femtosecond Pump-Probe Confocal Microscopy of ZnO Nanowire Lasers

University Of California-Berkeley, Berkeley CA

Investigators

Abstract

This is a NER proposal for a specific one-year trial to (1) characterize single ZnO nanowire laser structures using spatially-resolved confocal microscopy detection, and (2) to introduce pump - stimulated emission dump probing to study stimulated emission processes of single nanowire laser configurations. The requisite morphologies of ZnO nanowires have been produced and synthetic refinement will be performed to obtain the best quality crystalline patterns of multiple nanowires. Laser and confocal optical microscopy tools that are available in this laboratory will be used to optically excite ZnO single nanowire laser media and to detect spectrally and spatially resolved stimulated emission. These include novel ultrafast pump-dump experiments with a Ti:sapphire femtosecond laser. The fundamental science of the exciton-exciton scattering mechanism to produce stimulated emission in crystalline nanowires and the transition to an electron-hole plasma stimulated emission mechanism will be explored. These studies are designed to develop new confocal microscopy methods to interrogate nanowire laser devices, with the specific ability to explore a single device at a time. Single molecule spectroscopy experiments have revealed a number of intriguing aspects of individual molecular environments over the last few years. These studies are intended to transfer this remarkable type of investigation to the study of single nanowire lasers and stimulated emission.