New Nonlinear Optical Processes in Molecules at Infrared Frequencies.
Abstract
This report details progress in the study of optical nonlinearities in molecules at infrared wavelengths. The objectives have been to investigate triply resonant third harmonic generation and singly, two-photon resonant third harmonic generation. In the first area, the limiting process of multiphoton absorption has received emphasis. In the second area, work has concentrated on molecules which have very strong, narrow, two-photon resonances. The successful application of third harmonic generation techniques to study collisionless multiphoton excitation in sulfur hexafluoride was accomplished. Depending on the excitation frequency, one or two-photon processes have been identified which deplete the population of the discrete vibrational energy levels into the quasi-continuum. Similar third harmonic generation experiments have yielded lower conversion efficiency in ammonia than in sulfur hexafluoride. Only a single rotational level in ammonia is found to be resonant, so the susceptibility is only minimally enhanced. In the area of two-photon resonant molecules, the susceptibility and projected conversion efficiency has been calculated for deuterated methane. Because of the very narrow and strong two-photon resonance, the calculated third harmonic conversion is larger than has been observed in any gas phase molecule to date. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1979
- Accession Number
- ADA086206
Entities
People
- Michael F. Becker
Organizations
- University of Texas at Austin