Project Title:

New Four-Level All-Solid-State Laser Source Within the 1.5 to 4 Micron Range

08.08-7528
New Four-Level All-Solid-State Laser Source
	Within the 1.5 to 4 Micron Range
Solidlite Corporation
16150 N.E. 85th Street #217 V
Redmond, WA 98052
Larry G. Deshazer  (206-882-7582)
LaRC -- NAS1-18619

Abstract:

	 A novel, four-level, solid-state laser based on a new combination of rare-earth
ions was proposed for use in remote atmospheric sensing and space-based lidar systems
that require radiation sources in the near infrared (NIR). Operation of current NIR
lasers involves quasi-three-level lasers with associated problems of strong temperature
dependence with increased thresholds and reduced efficiencies at room temperature.
In the new four-level laser, one ion acts as the sensitizer selectively absorbing
the diode pump light. The sensitizer ion transfers the pump energy to the other rare-earth
ion which performs as the laser-active ion. 
	Phase I studied two oxide crystals co-doped, for the first time, with the selected
ion pair. Fluorescence, absorption, and excitation spectra were investigated. It
was learned that the host should be a crystal with low-energy phonons, such as yttrium-lanthanum-fluoride
(YLF), for the laser-diode-pumped NIR laser. In addition, YLF is an uniaxial crystal
giving polarized emission which would enhance by two-fold the laser gain coefficients
perpendicular to the optical axis and would reduce the problems concerning thermal
loading of the laser crystal.

Potential Commercial Application:

Potential Commercial Application: Commercial applications would be in remote sensing
of atmospheric constituents and pollutants, sensing industrial leaks and spillage,
and providing new wavelength coverage for scientific and medical instruments. An
efficient eye-safe laser could be used in wind sensing, low power materials processing,
and remote bar code reading.