Optical element and interferometer

Abstract

The disclosed optical element (20) is configured from surfaces that form the apex angle of each of a first through fourth triangular prism (21, 22, 23, 24) being adhered together; each of the bonded surface (21a, 22b) pair between the first and second triangular prisms, the bonded surface (22a, 23b) pair between the second and third triangular prisms, the bonded surface (23a, 24b) pair between the third and fourth triangular prisms, and the bonded surface (24a, 21b) pair between the fourth and first triangular prisms is bonded with an optical thin film therebetween; and each optical thin film has the characteristics of transmitting or reflecting incident light in accordance with the polarization state thereof. The optical element (20) splits a light path at a first position (P1) at the optical thin film, and combines light paths at a second position (P2) at the optical thin film.

Description

technical field [0001] The invention relates to an optical element and an interferometer. Background technique [0002] At present, it is known that the light from the light source can be divided into measurement light (object light) and reference light, so that the measurement light transmitted or reflected by the measurement object and the reference light overlap to cause interference, and the state of the interference is analyzed to measure the measurement object. A Mach-Zehnder interferometer that measures the bump and phase changes of the Moreover, it is also known that the Mach-Zehnder interferometer is additionally modulated to measure the light frequency acousto-optic element, so that the frequency-modulated measuring light and reference light interfere and produce a heterodyne interferometer (for example, JP-A-2003-90704 Bulletin). [0003] Figure 16 A configuration example of a heterodyne interferometer is shown. exist Figure 16 The interferometer 100 shown in...

AI Technical Summary

Problems solved by technology

[0008] Figure 16 The problem with the shown conventional interferometer is that since there is an air gap for optical path length adjustment between the optical elements constituting the interferometer, it takes a lot of time to adjust the optical axis of each optical element. And the problem that the optical axis deviation of each optical element due to external vibration, etc., affects the light intensity at the time of detection

Another problem is that there are many reflective surfaces and transmission surfaces on the optical path, so the light intensity at the time of detection is reduced due to surface reflection, etc.

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