Optical system for oblique incidence interferometer and apparatus using the same
AssigneeFuji Photo Optical Co., Ltd.
InventorsHideo Kanda, Fumio Watanabe, Fumio Kobayashi
Life of this patent
Estimating the term…
Abstract
In an optical system for an oblique incidence interferometer, first and second prisms are used for luminous flux dividing and for luminous flux combining, respectively. Reference light and measurement light are separated from each other at a surface where collimated coherent light enters or exits from the first prism, whereas the reference light and measurement light are combined together at a surface where the measurement light enters or exits from the second prism.
Claims14
An optical system for an oblique incidence interferometer, in which collimated coherent light is divided by luminous flux dividing means, one of thus obtained luminous fluxes is used as reference light, the other luminous flux is used as measurement light made obliquely incident on a test surface, said reference light and said measurement light reflected by said test surface are combined together by luminous flux combining means so as to interfere with each other, and thus generated interference fringes are formed on an interference fringe observing screen;
- wherein said luminous flux dividing means comprises a first prism, said reference light and measurement light being separated from each other at a surface where said coherent light enters said first prism or a surface where said coherent light exits from said first prism;
- and
- wherein said luminous flux combining means comprises a second prism, said reference light and measurement light being combined together at a surface where said measurement light enters said second prism or a surface where said measurement light exits from said second prism.
Dependencies are inferred from the claim text.