FIZEAU LENS

摘要

PROBLEM TO BE SOLVED: To miniaturize the size and reduce the weight by reducing a maximum lens diameter in a Fizeau lens.;SOLUTION: A Fizeau lens 10 includes a Fizeau plane 4b, as an outermost lens plane, that divides laser light Q₃ from a laser light source 6 into a test object surface reflected luminous flux Q₅ forming an interference reference wave plane, and a measurement luminous flux Q₄ to be focused on a test object surface 5a. This Fizeau lens is disposed with, in order from an object side where laser light Q₃ enters, a negative meniscus lens the convex face of which faces the object side, and a positive lens group having a positive refractive power and having the Fizeau plane disposed closest to the image side.;COPYRIGHT: (C)2012,JPO&INPIT