COHERENT BEAM DEVICE FOR SAMPLE OBSERVING MEASUREMENT

摘要

PROBLEM TO BE SOLVED: To solve a problem that a protective glass needed at the incident side of an image pickup camera to protect an image pickup face generates a noise interference fringe in a coherent observing device using a coherent beam and an image pickup camera. SOLUTION: A dustproof vessel includes an image formation lens system placed at the incident side of the image pickup camera, in which the image pickup camera is placed. The protective glass is made unnecessary by providing an image formation lens system with the function of the protective glass to protect the conventional image pickup face.