Growth and Tailoring of Photorefractive Fibers Using the Laser Heated Pedestal Growth Method
Final rept. 1 Sep 2001-31 Aug 2002
GEORGIA UNIV ATHENS DEPT OF PHYSICS AND ASTRONOMY
Pagination or Media Count:
Because of detailed evaluation of the quality of our LHPG fibers by Dr. D. Evans of the AFRL, we were able to pinpoint the cause of the majority of the defects in our Laser Heated Pedestal Growth LHPG fibers. The principal defects found in our materials lay in the non-uniformity of the diameter of our fibers and in the fact that the fibers contained cracks and striations, especially the thinner fibers, which adversely affect optical transmission. In addition, the fibers were grown in air and showed a dark coloration which required additional treatment and annealing to render transparent. In the course of this period of the grant, we designed and constructed a new LHPG pulling system which remedied the causes of the problems mentioned above. The new LHPG system is totally enclosed in a chamber which allows regulation and control of the atmosphere and temperature in which the fibers are pulled. In addition to air, the system can now accommodate admixtures of nitrogen, oxygen and hydrogen as well a partial vacuum. Fibers of LiNbO3 grown in the new system under an oxygen atmosphere, for example, no longer show any coloration. We believe the controlled atmosphere also aids in reducing crystalline flaws.
- Refractory Fibers
- Lasers and Masers