title: Optical cavity characterization in nanowires via self-generated broad-band emission.
abstract: Broadband white light is of great spectroscopic value and would be a powerful tool for nanoscale spectroscopy, however, generation and direction of white light on this length scale remains challenging. Here, we demonstrate the generation of broadband white light in sub-wavelength diameter Gallium Nitride (GaN) wires by coincident one- and two-photon absorption mediated via defect states. This generation of broadband, "white" light enables single-nanowire interferometric measurements of the nanowires themselves via analysis of the Fabry-Pérot fringes that overlay the entirety of the emission spectrum. The quality factor and finesse of individual nanowire cavities were measured and calculated to be 186 ± 88 and 3.05 ±0.6 respectively, averaged over 20 individual wires. This work presents a new, simple approach for the generation and direction of broad band white light at sub-diffraction limit length scales, ideal for translating classical white light spectroscopies to higher spatial resolutions then previously achieved.
authors.affiliation: The Molecular Foundry, Lawrence Berkeley National Laboratories, Berkeley, CA 94720, USA.
authors.forename: Adam M
authors.initials: AM
authors.lastname: Schwartzberg
authors.forename: Shaul
authors.initials: S
authors.lastname: Aloni
authors.forename: Tevye
authors.initials: T
authors.lastname: Kuykendall
authors.forename: P James
authors.initials: PJ
authors.lastname: Schuck
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Urban
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D008027:Light; D008029:Lighting / Q000295:instrumentation*; D036103:Nanotechnology / Q000295:instrumentation*; D043942:Nanotubes / Q000737:chemistry* / Q000528:radiation effects; D055096:Optical Devices