It is deep double refraction measurement at ultraviolet wave length

摘要

Topic The optical element, especially, it is deep ultraviolet (DUV), offer the device and method in order to measure the double refraction quality of the optical kind of element which is used for wave length accurately.SolutionsThe device includes, the sample (136) two photoelastic modulators which are arranged on both sides (PEM) (126 and 128). Each PEM in order to modulate the polarity of the light beam which passes the sample, is operation possible. As for the device, in addition, the polarizer which is connected to on the one hand PEM (124) with, the analyzer which is connected to other PEM (130) with, two PEM, after passing the polarizer and the analyzer, the detector in order to measure the strength of light (132) with it includes. You can obtain the technology in order to measure double refraction quality over wide scope. For example, execution example of the double wave length illuminant is offered in order to measure the double refraction of relatively high level. In addition, from many techniques in order to decide double refraction quality on the basis of the appraisal value or estimator of the double refraction which is inspected because of the optical element which is given as the sample, technology in order to select the accuracy and effective technique is offered. Selective figure Figure 3