Rotational Relaxation and Self-Induced Transparency in HF Gas
Abstract
The measurement of laser linewidth using time-resolved bleachable absorption of HF gas is reported. The pin lasers were found to have a width of only 3 MHz, which is 120 times narrower than the Doppler width of the lasing transition. The authors adopted a single-laser pump-probe technique whereby a single laser pulse of microsecond duration is broken into saturating pumping radiation followed by weak probing radiation using a Pockel's cell optical switch. Preliminary measurements of rotational relaxation times in HF at several tens of millitorr are presented for several P1(J) transitions: the values obtained are in agreement with values obtained from Lorentz pressure- broadening data. At a high incident laser intensity, the absorbing transition of the HF was saturated (bleached) and the later portions of the laser pulse passed without attenuation. In addition to this bleaching, transmitted pulses were obtained whereby the energy absorbed from the leading edge appeared later in the pulse. In portions of the transmitted pulse the energy actually exceeded that of the incident pulse and the net energy loss was anomalously small. At the highest laser intensities, damped oscillations were observed in the transmitted output. These anomalies are believed the result of self-induced transparency and optical nutations, respectively.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1974
- Accession Number
- AD0782034
Entities
People
- C. B. Arnold
- G. H. Lindquist
- L. M. Peterson
Organizations
- Environmental Research Institute of Michigan