Measurement of the Variations in Thickness and Refractive Index of NIF Crystals

Sommargren, G E ; Phillion, D W ; Johnson, M A ; Bradsher, L S

Lawrence Livermore National Laboratory

关键词: 99 General And Miscellaneous//Mathematics, Computing, And Information Science;    Refractive Index;    Thickness;    Lasers;    Interferometers;   

DOI  :  10.2172/15002093
RP-ID  :  UCRL-ID-147764
RP-ID  :  W-7405-ENG-48
RP-ID  :  15002093

美国|英语

来源: UNT Digital Library

【 摘 要 】

This report discusses one method of characterizing the variations in the physical thickness and refractive index of NIF doubler, tripler and switch crystals that are relatively thin ({approx}10mm thick). These particular measurements are difficult to perform with standard laser interferometers when the front and back substrate surfaces are near-parallel. A complicated interference pattern is formed from the interference of more than two beams due to the temporal coherence of the laser source. There are a number of methods that can be used to minimize this problem. They are referenced in a paper by Peter de Groot. In this report we discuss a method that eliminates the problem completely and show the results of measurements of two crystals.