RU2714865C1 - Interferometer - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: invention relates to engineering physics. Interferometer has a laser stabilized in power and wavelength He:Ne, having a magnetooptical insulator installed at its output and 5-coordinate device for setting laser radiation into optical fiber, by means of which it is connected to a fiber-optic light beam splitter, which divides the light beam into the first and second coherent optical channels, each of which comprises series-installed optical fiber polarization controller, phase-shifting element and reference spherical wave source, wherein both phase-shifting elements are connected to two-channel controller. Interferometer also has a recording device with two digital video cameras, optically coupled with a source of a reference spherical wave of the first coherent optical channel, and 5-coordinate table at the output of the interferometer for setting up a wavefront corrector.

EFFECT: technical result consists in creation of compact interferometer with possibility of its use with both horizontal and vertical orientation of optical axis, which allows more efficient performance of its functions.

1 cl, 1 dwg

Description

The invention relates to technical physics, in particular to tools for research and measurement of optical elements and systems, and can be used in technical diagnostics, for example, to control parameters and progress of technological processes.

Known low-coherence interferometer with a diffraction comparison wave (patent RU 2547346) containing a source of low-coherent light, polarization controllers and a source of two reference spherical waves.

The disadvantages of the known solutions include the complexity of the optical design and the entire design of the interferometer, as well as the insufficient efficiency of the interferometer.

The objective of the invention is to create a compact interferometer with the possibility of its use with both horizontal and vertical orientation of the optical axis, which allows more efficiently perform their functions.

The problem is solved in that the interferometer contains a laser stabilized in power and wavelength He: Ne with a magneto-optical insulator installed at its output and a 5-axis device for laser radiation into an optical fiber, with which it is connected to an optical fiber beam splitter light dividing the light beam into the first and second coherent optical channels, each of which contains sequentially mounted fiber optic polarization controller, phase shifting an element and a reference spherical wave source, while both phase-shifting elements are connected to a two-channel controller, the interferometer also contains a recording device with two digital video cameras, optically coupled to a reference spherical wave source of the first coherent optical channel, and a 5-coordinate table at the output of the interferometer for installation wavefront corrector.

The invention is illustrated in the drawing, where in FIG. 1 shows a block diagram of an interferometer.

The main elements of the interferometer are He: Ne laser 1 stabilized in power and wavelength with a magneto-optical isolator and a 5-coordinate device for fusing laser radiation into optical fiber 2. The light after being fed into the optical fiber enters the fiber optic beam splitter 3, which is divided into two coherent optical channels with an intensity in each of approximately 1: 1. Then the light in each channel hits the fiber optic polarization controllers 4.1 and 4.2. Light from channel 4.2 enters the phase-shifting element 5.2 to control the phase characteristics of the front at the output of the reference spherical wave (IESW) 7.2. The light from channel 4.1 enters the phase-shifting element 5.1 to control the phase characteristics of the front at the output of a reference spherical wave source (IMIESV) integrated with a flat mirror 7.1.

The phase-shifting elements 5.1 and 5.2 are controlled from a two-channel controller 6. In turn, the control signals to the two-channel controller 6 are received from a digital video camera 9.1, on which the interference pattern is recorded.

The spherical diverging wave of the IESW 7.1 partially illuminates the investigated part 11, partly directed to the optical recording device 8. The wavefront reflected from the studied part 11 (working front) is focused on a flat mirror IMIESV 7.1, in the immediate vicinity of the IESW and further along with the reference front extends in the direction of the optical part of the recording device 8. The optical part of the recording device is formed by an input lens and two lenses. Registration of the interferogram is performed using a digital video camera 9.1.

Taking into account the concept of the device, the lens is selected of the type that provides the image of a point source at infinity, and the lenses build an image on a video camera. This concept allows you to set the lens with a different working aperture, without changing the relative position of other optical elements.

The concept of the interferometer provides a flat mirror located between the lenses in the recording device 8, which can be entered / withdrawn from the beam. In the image plane of the optical system formed by the lens, the first lens and a flat mirror, a second video camera 9.2 is installed, on which IMISV 7.1 image is formed. The signal from the camera is also output to the computer monitor. This additional channel allows you to configure the investigated part remotely, according to the picture from the monitor.

When studying convex or aspherical parts, a 5-coordinate table is provided at the output of the interferometer for installing a wavefront corrector 10, which converts a diverging spherical front into a desired shape (converging, flat or aspherical).

The main advantages over a low coherent interferometer (patent RU 2547346):

- a He-Ne laser stabilized in frequency and power, providing less phase distortion of the wavefront, thereby increasing the accuracy of measurements;

- there is no delay line, which simplifies the optical design and design of the interferometer;

- simplifies the design of the source node of the reference spherical wave, instead of two sources, one is used;

- the optical part of the recording device is constructed in such a way that it is possible to change the working aperture of the interferometer by only replacing the lens without adjusting the other optical elements of the recording device.

A flat mirror and a second camera are introduced into the design of the interferometer, allowing remote tuning of the studied part, looking at the computer monitor, which displays an image of the area with the source of the reference spherical wave (previously it was necessary to remove the video camera, use a special eyepiece, and reconfigure the optical part of the recording system to obtain images of the area of the source of the spherical wave, stretch (if you get it) and somehow align the part.

The lenses of the optical device of a part of the recording system are designed in such a way that coma aberration is minimized when the working and reference fronts pass through the optical part of the recording system.

Claims (1)

An interferometer that contains a laser stabilized in power and wavelength He: Ne with a magneto-optical insulator installed at its output and a 5-coordinate device for laser radiation into optical fiber, with which it is connected to an optical fiber beam splitter that divides the light beam into the first and second coherent optical channels, each of which contains a sequentially installed fiber optic polarization controller, a phase-shifting element and a reference spherical source second wave, and both the phase-shifting element connected to the dual controller, the interferometer further comprises a recording device with two digital cameras is optically conjugate to the reference source of the first spherical wave coherent optical channel, and 5-axis table at the output of the interferometer to set the wavefront corrector.

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