Investigation of Superradiant LDV Markers and Three-Component Velocity Mapping.
Abstract
Research areas were: 1) micrometer-size droplets; 2) three-dimensional scalar mapping; and 3) three-dimensional velocity mapping. Nonlinear optical interactions in a droplet occur at remarkably low input intensity levels because the droplet acts as a lens to concentrate the input radiation at a location just within the shadow face and as an optical cavity to provide feedback for the internally generated radiation. The following nonlinear optical effects have been observed in single droplets: lasing; stimulated Raman scattering up to the 14th order; coherent Raman gain due to the presence of another input wave; phase-modulation broadening of the elastically scattered and stimulated Raman scattered radiation; delay time in generating the multiorder stimulated Raman scattering; and effective Q-factor of the droplet cavity based on a lifetime measurement of the radiation trapped within the droplet. Laser-induced breakdown within the droplet occurs when the rising portion of the input laser pulse causes multiphoton ionization, which is followed by cascade multiplication. The resultant plasma within the droplet transforms a nominally transparent droplet into an absorping droplet, and the remaining portion of the input laser pulse heats the droplet. Plasma is ejected from the droplet, first from the shadow face and then from the illuminated face. Once the plasma has been quenched, the droplet undergoes explosive vaporization. Three-dimensional scalar mapping was made possible by sweeping the laser illumination sheet and by recording scattered images on a high-speed framing camera.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 10, 1988
- Accession Number
- ADA195504
Entities
People
- Marshall B. Long
- Richard K. Chang
- Roman Kuc
Organizations
- Yale University