Pulse Compression of CO2 laser by Optical Free Induction Decay (OFID) Effect in Dymel Gas
Abstract
Pulse compression of a laser can be accomplished by using OFID technique in IR gases such as ammonia and CH3F [1]. Earlier work used OFID effect at the falling edge (ON to OFF) of a laser pulse. Results of a CO2 laser pulse compression in Dymel gas are reported in the present paper. A unique feature of this experimental investigation is the presence of OFID effect on a rising edge (OFF to ON). This feature requires minimum instrumentation as compared to the conventional OFID set up. A pulsed CO2 laser, test cell with Dymel (1,1 DI-Fluoroethane,C2H4F2), a beam splitter, a digital oscilloscope, and a fast IR pulse detector were used to compress and record pulses of the CO2 laser. Average of 40 pulses was recorded for a typical pressure of Dymel varying from 0 to 25 torr. Results indicate that the original laser pulse(at vacuum condition) could be compressed to one quarter of it's width by adding merely 6 torr of Dymel gas in the test cell. The ratio of intensity to pulsewidth indicated a four times sharper pulse at a pressure of 6 torr of Dymel. These results and explanation of rising edge OFID mechanisms based upon polarization of gas molecules will be presented. [1] E. Yablonovitch, and J. Goldher, " Short Co2 Laser Pulse Generation by Optical Free Induction Decay", Applied Physics Letters, Vol. 25. No. 10, Nov. 1974, pp. 580-582.
- Publication:
-
APS Annual Gaseous Electronics Meeting Abstracts
- Pub Date:
- October 2002
- Bibcode:
- 2002APS..GECGTP073Y