Research Investigation Directed Toward Extending the Useful Range of the Electromagnetic Spectrum
Abstract
JSEP research has yielded two new laser microprobes for use in electronics fabrication. The development of such probes is increasingly important because of the need for precision in situ monitoring in advanced electronics fabrication. In the first, photoelectric emission induced by a focused UV laser beam has been used for the first time to make a scanning photoemission microscope for probing semiconductor surfaces. With this instrument it was possible to map regions of different doping levels on a silicon surface. The spatial resolution was found to be limited only by the laser beam spot size. In addition, Raman microprobe spectroscopy has been used to profile locally doped regions in GaAs with micrometer-level resolution. This is an important in-situ diagnostic technique for compound semiconductors. We have investigated ways of making improved sources of silent light (also known as photon-number-squeezed light or sub-Poisson light), and determined how such light behaves when it impinges on simple optical elements such as dielectric beamsplitters. In addition, we have used the novel ultrafast optical technique of time-delayed-four-wavemixing (TDFWM) to measure optical dephasing phenomena in semiconductor doped glasses. Dephasing times as short as 18 fsec were observed at room temperature with no evidence of modulated structure. Keywords: Light; Photons; Poisson density functions; Quantum theory; semiconductors; Electromagnetic spectra.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 31, 1989
- Accession Number
- ADA217460
Entities
People
- George W. Flynn
- Richard M. Osgood, Jr.
Organizations
- Columbia University