Preparation and Single Crystal Growth of Er,Tm,Ho Doped YLiF4Laser Materials.

摘要

This report describes a continuation of research efforts to prepare high purity rare earth fluorides, grow single crystals of Er, Ho, and Tm doped YLiF4, and test fabricated laser rods for operation at 2.06 micrometers. All fluorides were prepared by hydrofluorination of of 99.99 + % commercial oxides at 800 - 1200C in a platinum reactor. Single crystal growth was performed in a N2-HF atmosphere using a top seeded solution method. A platinum furnace was developed along with a diameter control device based on continuous crystal weighing. High quality scatter-free single crystals were grown in 10 - 15 mm diameter and 6 - 10 cm length. Laser rods of (3 x 30) mm size and a axis orientation were finished for several compositions. Both long pulse and Q-switch tests were run on five rods. These indicate that a favorable composition may lead to room temperature operation. Some damage occurred during the Q-switch tests but is not unique to the preparation or growth.