SBIR-STTR Award

This program seeks to develop ytterbium doped rare earth sesquioxides including yttria, scandia, lutetia, and gadolinia-based oxides as laser gain media for use in high power thin disk lasers.  The increased thermal conductivity, increased absorption cross section at pump wavelengths, small quantum defect in Yb lasing systems, and high performance demonstrated in such media are attractive.  Processing via liquid precursor flame spray pyrolysis will be used to produce highly sinterable nanopowders for subsequent consolidation, sintering, and HIPping to form transparent materials for optical transmission, thermal conductivity, and lasing test measurements.

Benefit:
The materials developed in this program will have direct application to high power laser systems utilizing thin disk architectures.  The high power output and high beam quality  of such lasers has already been demonstrated by companies including Boeing and Trumpf.  The new materials will allow lower heat losses, more efficient heat removal, and more efficient pump power absorption than that currently possible using YAG based gain media.  In addition to high power laser defense systems, lasers based on these materials will find application in industrial cutting and welding applications as well.

Keywords:
Thin-Disk, High Power Laser, Ytterbium, Yttrium, Scandium, Lutetium, Gadolinium, Oxide

Rare earth sesquioxide transparent ceramics doped with ytterbium are being developed for use in thin disk lasers due to their favorable thermal and optical properties. Nanocrystalline oxide powders are produced using liquid feed flame spray pyrolysis. Particular emphasis is placed on production of high purity powders that can be consolidated to without the formation of second phase scattering centers. Consolidation is accomplished using either wet or dry forming techniques, followed by sinter/HIP to achieve full density. Composite structure fabrication will be investigated. Characterization of optical, mechanical, and thermal properties will be performed.

Benefit:
The proposed work will bring a new class of materials to the table for the fabrication of thin disk lasers. The thermal conductivity, absorption cross section, and high optical efficiency possible in ytterbium doped systems combined with the high beam quality possible from a thin disk laser will provide high power generation from a small package for military and commercial laser applications.

Keywords:
Thin Disk Laser, Ytterbium, Sesquioxide, Polycrystalline Laser Gain Media, Yttria, Lutetia, Scandia