CN102073122B - Concentric assembly method for concentric optical element in off-axis concentric optical system - Google Patents

Abstract

A concentric assembly method for a concentric optical element in an off-axis concentric optical system relates to the field of optical instrument, and solves the problems that the existing off-axis system cannot realize high accuracy concentric assembly for concentric optical element and the detection accuracy is low. The method specifically comprises the following steps: 1) simultaneously transmitting a reference beam and a detection beam by the light source of an interferometer, wherein the detection beam simultaneously enters a first and a second optical elements through a standard lens set, the detection beam is then reflected to the standard lens set from the surface of the first and the second optical elements, and the detection beam returning to the standard lens set is interfered with the reference beam to form interference fringes; and 2) obtaining the de-focusing amount of the first and the second optical elements according to the interference fringes in the step 1); and thepositions of the first and the second optical elements are adjusted according to the de-focusing amount, thereby concentrically assembling the optical elements. The light path has high applicability and high accuracy.

Description

Concentric assembly method for concentric optical elements in off-axis concentric optical system

technical field

The invention relates to the field of optical instruments. In particular, it relates to a concentric assembly method for concentric optical elements in an off-axis concentric optical system.

Background technique

All concentric optical elements in the off-axis concentric optical system are spherical, and the centers of all spherical surfaces are located at one point. This concentricity makes the optical system have the advantages of good imaging quality, simple structure, easy realization, and miniaturization. It has been more and more widely used in the field of spectroscopic instruments, especially imaging spectrometers. Environmental pollution assessment, medical diagnosis and treatment and many other fields have broad application prospects. The high-precision assembly and detection of the off-axis concentric spherical surface in the concentric system is the key to realize and measure the performance of the instrument. At present, there are no relevant reports on the high-precision assembly and detection methods of the concentric spherical surface of the system, which affects the promotion of the application field of the concentric system to a certain extent.

Contents of the invention

In order to solve the problems that the high-precision concentric assembly of the concentric optical elements in the existing off-axis system is difficult to realize and the detection accuracy is low, the invention provides a concentric assembly method for the concentric optical elements in the off-axis concentric optical system.

A concentric assembly method for concentric optical elements in an off-axis concentric optical system, the method is realized by the following steps:

Step 1. The light source of the interferometer emits a reference beam and a detection beam at the same time, and the detection beam is simultaneously incident on the first optical element and the second optical element through the standard lens group, and then reflected by the surface of the first optical element and the second optical element Returning to the standard lens group, the detection beam returning to the standard lens group interferes with the reference beam to form interference fringes;

Step 2. Obtain the defocus amount of the first optical element and the second optical element according to the interference fringes described in step 1; adjust the position of the first optical element and the second optical element according to the value of the defocus amount to realize the concentricity of the optical element assembly;

The standard lens group described in step 1 is a standard compensating mirror that matches the surface shape and aperture of the first optical element and the second optical element; The position of the optical element is specifically: when the defocus difference between the first optical element and the second optical element is zero or close to zero, the concentric assembly of the two optical elements is realized; the first optical element The second optical element is a spherical mirror with the same surface shape.

Beneficial effects of the present invention: the concentric assembly method of concentric optical elements described in the present invention has strong practicability and high precision of the detection optical path, and effectively solves the high-precision concentric assembly of concentric spherical surfaces in off-axis systems.

Description of drawings

Fig. 1 is an optical path diagram of the concentric assembly method for concentric optical elements in an off-axis concentric optical system according to the present invention.

In the figure: 1. Interferometer, 2. Standard lens group, 3. First optical element, 4. Second optical element.

Detailed ways

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 1. This embodiment is described in conjunction with FIG. 1, which is used for the concentric assembly method of concentric optical elements in an off-axis concentric optical system. The method is implemented by the following steps:

Step 1. The light source of the interferometer 1 emits a reference beam and a detection beam at the same time, and the detection beam passes through the standard lens group 2 and enters the first optical element 3 and the second optical element 4 at the same time, and then passes through the first optical element 3 and the second optical element. The surface of the optical element 4 returns to the standard lens group 2 after being reflected, and the detection beam returned to the standard lens group 2 interferes with the reference beam to form interference fringes;

Step 2, obtain the defocus amount of the first optical element 3 and the second optical element 4 according to the interference fringes described in step 1; adjust the positions of the first optical element 3 and the second optical element 4 according to the value of the defocus amount, and realize Concentric assembly of optical components.

The specific process of generating optical interference fringes described in step 1 of this embodiment is as follows: the detection beam is a plane wave, which is transformed into a wave with the same surface shape as the first optical element 3 and the second optical element 4 through the standard compensation mirror and is incident at the same time To the surface of the two optical elements, adjust the position and angle of the first optical element 3 and the second optical element 4, so that the detection beam is incident on the surface of the two optical elements along the normal direction of each surface, and reflected by the surface of the two optical elements Then return to the compensation mirror along the original path, and then become a plane wave through the compensation mirror and interfere with the reference light.

The interference fringes obtained in step 2 of this embodiment can also detect the surface error of the first optical element 3 and the second optical element 4 .

The standard lens group 2 described in this embodiment is a standard compensating mirror matching the surface shape and aperture of the first optical element 3 and the second optical element 4 , and different standard compensating mirrors can be selected according to the surface shape of the optical element.

In step 3 of this embodiment, the adjustment of the first optical element 3 and the second optical element 4 according to the value of the defocus amount of the optical element; specifically: when the first optical element 3 and the second optical element 4 When the difference of the defocus amount is zero or close to zero, the concentric assembly of the two optical elements is realized.

The interferometer 1 described in step 1 in this embodiment is a double-beam single-frequency laser interferometer.

The optical element in this embodiment is a spherical reflector with the same surface shape and may be a concave spherical surface or a convex spherical surface.

The present invention can detect the concentricity accuracy of the assembled concentric optical elements, by measuring the defocus amount of the two optical elements, and then detect the centrifugal distance of the optical elements according to the defocus amount difference to determine the concentricity accuracy; the defocus The product of the difference value and the wavelength of the interferometer 1 is the centrifugal distance of the optical element. When the optical element is assembled concentrically, the centrifugal distance is zero or close to zero according to the actual project requirements; when the concentric detection is performed, the centrifugal distance is calculated; to achieve two Concentric assembly of optical elements.

Claims (3)

1. be used for the concentric fits method from axle concentric optical system concentric optical element, it is characterized in that this method is realized by following steps:

The light source of step 1, interferometer (1) sends reference beam simultaneously and detects light beam, described detection light beam is incident to first optical element (3) and second optical element (4) simultaneously through standard lens group (2), after first optical element (3) and the reflection of second optical element (4) surface, be back to standard lens group (2) then, described detection light beam and the reference beam generation interference of light that is back to standard lens group (2) forms interference fringe;

Step 2, obtain the defocusing amount of first optical element (3) and second optical element (4) according to the described interference fringe of step 1; Adjust the position of first optical element (3) and second optical element (4) according to the value of defocusing amount, realize the concentric fits of optical element;

The described standard lens group of step 1 (2) is and the face shape of first optical element (3) and second optical element (4), the standard compensation mirror that bore is complementary; The described value according to defocusing amount of step 2 is adjusted the position of first optical element (3) and second optical element (4), be specially: when the difference of the defocusing amount of described first optical element (3) and second optical element (4) is zero or close to zero the time, realize the concentric fits of two optical elements; Described first optical element (3) is the identical spherical reflector of face shape with second optical element (4).

2. according to claim 1ly it is characterized in that for the concentric fits method from axle concentric optical system concentric optical element the described interferometer of step 1 (1) is twin-beam unifrequency laser interferometer.

3. according to claim 1ly it is characterized in that for the concentric fits method from axle concentric optical system concentric optical element described the identical spherical reflector of shape can be concave spherical surface or protruding sphere.