ACOUSTIC SELF-TRAPPING OF LASER BEAMS
Semiannual technical summary rept. no. 1
PERKIN-ELMER CORP NORWALK CT
Pagination or Media Count:
Internal filamentary glass damage caused by high power Q-switched pulse lasers has been reported in the literature. Also, filamentary trapping in liquids has been observed. This report presents a theory of acoustic beam trapping. In the theory, electrostriction is the sound wave driving force and sound wave compressions cause focusing of the light wave fields. The theoretical trapping thresholds are calculated from the laser wavelength and the density, refractive index, Youngs modulus, and Poissons ratio of a solid material, or the density, refractive index, and speed of sound of a liquid medium. The acoustic trapping thresholds agree with experimental glass damage thresholds to within experimental accuracy, and they vary the same way with initial beam size. Trapping movies showing the formation of strongly focused regions are presented. An explanation is given for most of the salient features observed in the damage phenomenon. An analysis of Kerr effect trapping is also presented for purposes of comparison.
- Lasers and Masers