| 摘要 |
PROBLEM TO BE SOLVED: To provide a novel method of manufacturing a fluoride crystal by a Bridgman method, and a novel crucible. SOLUTION: In a method of manufacturing a fluoride crystal by a vertical Bridgman method, the shortest diameter of the section of a cavity 21 of a crucible 20 is made small, for example not greater than 2.5 cm long, when the shortest diameter is defined as a shortest distance in a sectional shape of the crucible cavity 21 for filling raw material powder. The shape of the cavity is not necessarily vertical, but it is possible to make many shapes for aimed use such as curved shapes and spiral shapes. Further, the crucible can be divided into some parts. The division in this way makes it possible to manufacture a fluoride crystal having a very small shortest diameter. The optical strain remaining in a crystal becomes small by making the shortest diameter small so that it is practically more advantageous than cutting out a small crystal actually used from a large crystal, further, a small crystal glows fast and has a low dislocation density. COPYRIGHT: (C)2009,JPO&INPIT |
