CN117871058A - Detection equipment and method for testing multi-optical axis parallelism - Google Patents

Abstract

The invention discloses a detection device and a method for testing multi-optical axis parallelism, wherein the detection device comprises an optical axis angle measurement module, a one-dimensional guide rail, a pentaprism and a roll angle test module; the rolling angle testing module consists of a rolling angle testing module A part and a rolling angle testing module B part, wherein the rolling angle testing module A part is fixedly connected with the pentaprism through a mechanical structure and moves along a one-dimensional guide rail together; the rolling angle testing module B part is fixedly connected with the optical axis angle measuring module through a mechanical structure, and the rolling angle testing module B part and the optical axis angle measuring module are fixed in the testing process; the optical axis of the optical axis angle measurement module is parallel to the optical axis of the roll angle test module; the optical axis of the optical axis angle measuring module is vertical to one right angle surface of the pentaprism; at least two branch optical axes of a plurality of optical branches of the device to be tested are perpendicular to the other right-angle surface of the pentaprism. The device can be used for multi-optical axis parallelism detection of photoelectric instrument equipment and military optical equipment, and the detection method has the advantages of good environmental adaptability and the like.

Description

Detection equipment and method for testing multi-optical axis parallelism

Technical Field

The invention belongs to the technical field of optical equipment, and particularly relates to detection equipment and method for testing multi-optical axis parallelism.

Background

Under the traction of various application demands, the photoelectric instrument has increasingly rich functions in the development process, such as multi-channel imaging, imaging and laser striking integration, laser emission and receiving integration, laser communication and remote sensing imaging integration and the like. The mode of combining the multiple functions in one photoelectric instrument device can better meet various application requirements, and has the advantages of low cost, small size, low power consumption, high stability, convenience in use and the like compared with a plurality of independent devices. The photoelectric instrument has the structural form of multiple light paths and multiple optical axes, and different optical branches are used for realizing different functions to jointly form complex photoelectric instrument equipment. For such multiple-path complex opto-electronic instrument devices, it is desirable that the directional consistency between the individual optical branches be within an allowable error range in order for the individual optical branches to work cooperatively, e.g., to aim at the same observation/striking area. The direction of each optical branch is generally defined as its optical axis, so multi-optical axis parallelism is one of the key indicators of such complex opto-electronic instrument devices. For example, in high orbit satellite laser communication, the parallelism between the laser receiving optical path and the laser transmitting optical path should be due to 1 angular second, otherwise, the two optical paths cannot be simultaneously directed to the laser communication terminal on the other side, so that duplex mode laser communication cannot be realized, and even communication cannot be realized at all. The index failure means that the product has serious defects, so that the multi-optical axis parallelism test of the photoelectric instrument equipment is an important link of quality assurance.

A variety of multi-axis parallelism detection methods for complex opto-electronic instruments have been developed. For the situation that no transverse space (or small transverse space) exists between the optical axes, for example, a multi-optical-axis system realized by combining and splitting the beams by using a dichroic mirror, the beams of a plurality of optical branches are basically overlapped in space, the detection can be performed by using an auto-collimator or collimator type method, the detection equipment can simultaneously receive the beams of each branch, and the angle detection of each beam is performed by using a color separation or time division mode, so that the multi-optical-axis parallelism detection is realized, the technology is mature, and the technology is widely applied to engineering.

However, for some electro-optical instruments, there are various limiting factors that inevitably exist lateral spacing between the optical branches, which are far apart. For example, in an artillery system, the system is composed of a visible light aiming system, an infrared aiming system, a laser emitting system, a laser receiving system and a plurality of muzzles, and a plurality of optical systems are typically separated, and a transverse distance of tens of centimeters exists between the systems. For such systems, the distance between the optical branches is larger, and more advanced ways are required to complete the multi-optical axis parallelism detection of such systems beyond the aperture coverage of such detection devices as autocollimators or collimator tubes.

For multi-optical axis parallelism detection with large spacing, the following methods are mainly adopted at present. (1) increasing the caliber of the collimator: the mode can cover a limited caliber range, the cost rises sharply along with the increase of the caliber, the detection equipment is heavy, the large-caliber collimator can generally only work in the state of horizontal optical axis, and the mode is not suitable for detecting the multi-optical axis parallelism of the photoelectric instrument equipment under other pointing conditions. (2) Moving an autocollimator or collimator in a plurality of optical branches based on electromechanical means (such as a two-dimensional moving platform): the method has the advantages that extremely high precision requirements are provided for the movement of the device, the cost is high, the testing time is long, the environmental adaptability is poor, and the environmental instability factors (such as structural deformation caused by temperature, environmental vibration, airflow change and the like) in the testing process also have obvious influence on the method; (3) Based on a plurality of theodolites test optical axes, the transmission angle reference is realized through mutual aiming among the theodolites: the method is limited by the accuracy of the theodolite, and the obvious influence of environmental instability factors in the testing process is not overcome; (4) The beam refraction is realized by utilizing a pentaprism or the beam transverse translation is realized by utilizing a double pentaprism, and the beam refraction or the beam translation is carried out to the same angle measuring equipment for angle test: when the pentaprism deflects or translates the light beam, the angle of the pentaprism can be kept in one direction, and the other direction is influenced by the error of the transversal rotation direction of the pentaprism around the optical axis, so that the mode still has extremely high requirements on the mechanical precision, and is also sensitive to the environment.

In summary, for large-pitch multi-axis parallelism detection, high-precision solutions are still lacking. The multi-optical axis parallelism detection problem of complex photoelectric instrument equipment has important significance for guaranteeing functions and performances of the complex photoelectric instrument equipment, and particularly, the photoelectric instrument equipment and military optical equipment which are used in the field and are required to have good environmental adaptability are required to have the following characteristics: high precision; the parallelism of the optical axis in a non-horizontal state can be detected; the cost is acceptable; the detection time is short; the detection method has good environmental adaptability.

Disclosure of Invention

Aiming at the problem of multi-optical axis parallelism test among different optical branches in a multi-beam optical system, the invention provides high-precision multi-optical axis parallelism detection equipment and method by combining a penta prism beam deflection technology on the basis of an interferometric-based roll angle test device and test method disclosed by the invention with a publication number of CN116772750A. The device can be used for detecting the multi-optical axis parallelism of photoelectric instrument equipment and military optical equipment, the maximum distance between optical branches can reach several meters, the precision can reach the level superior to 1 angular second, the cost is moderate, the detection time is short, and the detection method has the advantages of good environmental adaptability and the like. The detection device and the detection method can transversely translate the optical axis reference or the plane reference with high precision, and can be used in other fields, such as high-precision detection of planes, detection of parallelism between large-spacing mechanical reference planes, and the like.

The above purpose is achieved by the following technical scheme:

the detection equipment for testing the parallelism of multiple optical axes comprises an optical axis angle measurement module, a one-dimensional guide rail, a pentaprism and a roll angle test module; the rolling angle testing module consists of a rolling angle testing module A part and a rolling angle testing module B part, wherein the rolling angle testing module A part is fixedly connected with the pentaprism through a mechanical structure and moves along a one-dimensional guide rail together; the rolling angle testing module B part is fixedly connected with the optical axis angle measuring module through a mechanical structure, and the rolling angle testing module B part and the optical axis angle measuring module are fixed in the testing process; the optical axis of the optical axis angle measurement module is parallel to the optical axis of the roll angle test module; the optical axis of the optical axis angle measuring module is vertical to one right angle surface of the pentaprism; at least two branch optical axes of a plurality of optical branches of the device to be tested are perpendicular to the other right-angle surface of the pentaprism.

Further, the pentaprism adopts a hollow reflection form and comprises two reflection planes with an included angle equal to 22.5 degrees.

Further, the optical axis angle measuring module adopts reflection type and comprises an off-axis paraboloid and a turning plane reflector.

Further, the optical axis angle measuring module comprises a light source and a beam combiner, and the light emitted by the light source and the test light beam can emit a standard collimated light beam through the beam combiner.

Further, at the light outlet of the optical axis angle measurement module, a corner reflector is arranged, and the working surface of the corner reflector faces the optical axis angle measurement module.

Further, the roll angle testing module A part comprises a prism A; the roll angle testing module B comprises an interferometer and a prism B; after the parallel light beam emitted by the interferometer is refracted by the prism B, the emitted light beam vertically enters the inclined plane of the prism A, and after being reflected by the inclined plane of the prism A, the light beam returns to the interferometer in an original path for rolling angle test.

The invention also provides a detection method for testing the multi-optical axis parallelism, which is based on the detection equipment for testing the multi-optical axis parallelism and comprises the following steps:

s1, selecting two optical branches to be tested in an optical system to be tested, and adjusting the relative spatial position relation between the testing equipment and the optical system to be tested so that the movement track of the pentaprism along the one-dimensional guide rail can cover part of the calibers of the two optical branches to be tested;

s2, enabling the pentaprism to move along the one-dimensional guide rail to a light-emitting beam range of a first optical axis of one optical branch to be detected;

s3, under the condition that the pentaprism is aligned with the optical axis to be measured, simultaneously recording the angle reading of the optical axis angle measurement moduleAnd the reading of the roll angle test module part B +.>；

S4, enabling the pentaprism to move along the one-dimensional guide rail to be within a light-emitting beam range of a second optical axis of the optical branch to be detected;

s5, under the condition that the pentaprism is aligned with the optical axis II, simultaneously recording the angle reading of the optical axis angle measuring moduleAnd the reading of the roll angle test module part B +.>；

S6, calculating and obtaining the angle deviation of the optical axis of the optical branch to be tested relative to the first optical axis of the optical branch to be tested based on the test resultFor the optical axis parallelism error between two optical branches, the calculation formula is as follows:

，

in the calculation formula, small-angle approximation is adopted, and the relative error caused by the approximation is better than one thousandth in a typical angle range of 1 degree; in the 1-angle range, the relative error due to approximation is better than one ten thousandth.

Aiming at the problem of multi-optical axis parallelism test among different optical branches in a multi-beam optical system, the invention provides high-precision multi-optical axis parallelism detection equipment and method by combining a pentaprism beam deflection technology based on the prior research result of the applicant and the invention with the publication number of CN116772750A, namely an interferometric-based roll angle test device and test method. The device can be used for multi-optical axis parallelism detection of photoelectric instrument equipment and military optical equipment. The beneficial effects include the following aspects:

1. the detection precision is high, the rolling angle testing module and the optical axis angle measuring module can both reach 0.1-degree-of-angle-second precision, and after compensation, the sub-angle-second precision can be reached, and the actual detection precision is often limited by the self beam quality and system aberration of the equipment to be detected;

2. the range of the distance between the optical axes of the branch optical paths is large, the maximum distance is limited by the travel of the penta prism scanning guide rail, and the long travel can be realized because the requirement on the accuracy of the penta prism scanning guide rail is lower in the invention, so that the measurable distance between the optical axes can reach 3 meters typically;

3. the cost is moderate, the high-precision electromechanical motion is avoided, and compared with the mode of improving the detection precision by means of mechanical precision, the method has the advantage that the cost is greatly reduced;

4. the detection of the invention can be automatically completed, and the detection time of a single test is shorter;

5. the invention has good environmental adaptability, and the angle change caused by the environmental instability factors (such as structural deformation, environmental vibration, airflow change and the like) in the test process can be properly monitored and compensated in the test result, so that the invention can be suitable for various external field test applications with relatively bad environments.

6. The invention has good universal star for various multi-optical axis photoelectric instrument devices and military optical systems, the detection application is not limited to a visible light system, and the detection device can test infrared, ultraviolet and multiband mixed optical systems by adopting a reflection type pentaprism and a reflection type optical axis angle measuring module; the tested optical axis is not limited to the transmitting axis of the optical detection device, and the receiving axis of the optical branch can be tested;

7. the invention can be expanded to some precision angle measurement application fields outside the optical field, for example, the parallelism detection of a plurality of reference planes with transverse spacing can be realized based on an auto-collimation mode, and the method can be applied to the detection in precision machining.

Drawings

FIG. 1 is a schematic diagram of the structure of the present invention;

FIG. 2 is a schematic diagram of the operation of the double pentaprism according to the present invention;

FIG. 3 illustrates a multi-axis parallelism detecting apparatus including a reference beam according to an embodiment of the invention;

FIG. 4 illustrates a multi-axis parallelism detecting apparatus capable of testing a receiving optical axis according to an embodiment of the invention;

FIG. 5 is a diagram of a transceiver coaxial calibration of a test device described in an embodiment of the present invention;

FIG. 6 is a schematic diagram illustrating the parallelism between the application and the test reference plane according to the embodiment of the present invention;

the individual components in the figures illustrate: 1. an optical axis angle measurement module; 102. a light source; 103. a beam combiner; 2. a one-dimensional guide rail; 3. a pentaprism; 401. a roll angle test module A part; 402. a roll angle test module B section; 501. an optical axis I to be measured; 502. a second optical axis to be measured; 6. a compound prism; 7. a collimated light source; 8. an improved compound prism; 9. a reference plane to be measured; 10. and a corner reflector.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. It will be apparent that the described embodiments are only some, but not all, embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Example 1

As shown in fig. 1, a detection device for testing multi-optical axis parallelism in this embodiment includes an optical axis angle measurement module 1, a one-dimensional guide rail 2, a pentaprism 3, and a roll angle test module; the rolling angle testing module consists of a rolling angle testing module A part 401 and a rolling angle testing module B part 402, wherein the rolling angle testing module A part 401 is fixedly connected with the pentaprism 3 through a mechanical structure and moves along the one-dimensional guide rail 2 together; the rolling angle testing module B part 402 is fixedly connected with the optical axis angle measuring module 1 through a mechanical structure, and the rolling angle testing module B part and the optical axis angle measuring module 1 are fixed in the testing process; the optical axis of the optical axis angle measurement module 1 is parallel to the optical axis of the roll angle test module; the optical axis of the optical axis angle measuring module 1 is vertical to one right angle surface of the pentaprism 3; at least two branch optical axes (an optical axis one to be measured 501 and an optical axis two to be measured 502) of a plurality of optical branches of the device to be measured are perpendicular to the other right-angle surface of the pentaprism 3.

The rolling angle testing module is composed of a rolling angle testing module A part 401 and a rolling angle testing module B part 402, and the composition and the method are disclosed in detail in the invention of an interferometric-based rolling angle testing device and a testing method (publication number CN 116772750A). In the invention, the fringe angle difference between two interference areas is multiplied by a scale factor related to the wedge angle of a prism to obtain the roll angleIn addition, two components of the average fringe tilt angle between the two interference regions can be used to obtain two additional degrees of freedom of the roll angle test module A portion 401 relative to the roll angle test module B portion 402>. Wherein the subscripts are the values of x, y, and z, which respectively represent the rotations about the x-axis, about the y-axis, and about the z-axis in the set coordinate system of the present invention, as follows. The above three angle readings->The angular pose of roll angle test module a portion 401 relative to roll angle test module B portion 402 is fully described.

With the above-mentioned scheme, a detection apparatus for testing multi-optical axis parallelism according to the present embodiment, the detection method for testing multi-optical axis parallelism includes the following steps:

s1, selecting two optical branches to be tested in an optical system to be tested, and adjusting the relative spatial position relation between the testing equipment and the optical system to be tested so that the movement track of the pentaprism along the one-dimensional guide rail can cover part of the calibers of the two optical branches to be tested;

s2, enabling the pentaprism to move along the one-dimensional guide rail to a light-emitting beam range of a first optical axis of one optical branch to be detected;

s3, under the condition that the pentaprism is aligned with the optical axis to be measured, simultaneously recording the angle reading of the optical axis angle measurement moduleAnd the reading of the roll angle test module part B +.>；

S4, enabling the pentaprism to move along the one-dimensional guide rail to be within a light-emitting beam range of a second optical axis of the optical branch to be detected;

s5, under the condition that the pentaprism is aligned with the optical axis II, simultaneously recording the angle reading of the optical axis angle measuring moduleAnd the reading of the roll angle test module part B +.>；

S6, calculating and obtaining the angle deviation of the optical axis of the optical branch to be tested relative to the first optical axis of the optical branch to be tested based on the test resultFor the optical axis parallelism error between two optical branches, the calculation formula is as follows:

in the calculation formula, small-angle approximation is adopted, and the relative error caused by the approximation is better than one thousandth in a typical angle range of 1 degree; in the 1-angle range, the relative error due to approximation is better than one ten thousandth.

Example 2

The difference between this embodiment and embodiment 1 is that, for the wavelength bands of ultraviolet or infrared, or more than one wavelength band is included in multiple branches of the optical system, the optical axis angle measurement module 1 may adopt a reflective type, typically consists of an off-axis paraboloid and a necessary turn-over plane mirror; the pentaprism can adopt a hollow reflection form and consists of two reflection planes with an included angle equal to or approximately equal to 22.5 degrees.

Example 3

As shown in fig. 2, the difference between the present embodiment and embodiment 1 is that two pentaprisms are used to test two optical branches in the present embodiment, wherein one pentaprism is fixed in the optical path of the farther optical branch for turning the light beam of the optical path; for the other closer optical branch, the composite prism 6 moves along the guide rail, the composite prism 6 is formed by combining a penta prism and a 22.5-degree prism, a partial reflection film is used at the common surface of the penta prism and the 22.5-degree prism which form the composite prism 6, the beam deflected by the penta prism fixed in the optical path of the farther optical branch can penetrate the composite prism 6, the composite prism 6 moves to the light outlet of the other optical branch to be tested, and the optical axis angle test can be performed after the beam passes through the deflection. Similarly, the composite prism 6 also has a corresponding roll angle test module a portion 401 connected thereto for roll angle monitoring thereof. In the test method, the test result of the pentaprism fixed in the light path of the farther optical branch is subtracted from the angle measurement result of the compound prism 6, and then the standard measurement calculation is performed. The expansion mode can further improve the environment interference resistance of the test method, such as the influence of vibration on measurement, the influence caused by the change of airflow and the stress difference of related mechanical structures along with temperature and working angles.

Example 4

As shown in fig. 3, this embodiment is different from embodiment 1 in that in order to further improve the test stability, a collimated light source 7 is used to connect with the one-dimensional guide rail 2, and the direction of the optical axis thereof is made to be the same as or close to that of the one-dimensional guide rail 2. Instead of a pentaprism, a modified compound prism 8 was used, which was composed of a pentaprism and a 22.5-degree prism, and a partially reflective film was used at the common surface thereof. The modified compound prism 8 can turn the beam from the optical branch and also transmit the reference beam from the collimated light source 7. Test method, for improved compound prism 8Angle measurement result of folded beamAnd subtracting the corresponding component of the test result of the collimation light source from the component, and performing the standard measurement calculation.

Example 5

As shown in fig. 4, the difference between the present embodiment and embodiment 1 is that the present invention can expand the function of testing the receiving axis of the optical branch, expand the optical axis angle measuring module, add the light source 102 and the beam combiner 103, and make it possible to emit a standard collimated beam while testing the angle of the incident beam, and the collimated beam can be incident into the optical branch to be tested after being folded by the pentaprism. After the standard collimated light beam enters the optical branch to be detected, if the optical branch to be detected contains a receiving part (such as an area array detector, such as a four-quadrant detector), the light spot position of the detector inside the optical branch to be detected is utilized, and based on the focal length of the optical branch, the included angle between the optical axis corresponding to the center point of the detector and the collimated light beam can be obtained, so that the angle detection of the receiving axis of the optical branch is realized. By switching the operating wavelength of the light source 102, a variety of standard collimated light beam outputs of different wavelengths can be achieved for testing different optical branches.

Example 6

As shown in fig. 5, this embodiment is different from embodiment 1 in that, for a multi-optical axis parallelism detecting apparatus having a receiving axis testing function, in order to further improve the accuracy, a corner reflector 10 may be attached at the light outlet of the optical axis angle measuring module 1, with the working face of the corner reflector 10 facing the optical axis angle measuring module 1. The corner reflector 10 can be removed from the optical path by electric or manual means, and after calibration, removed, and subjected to a standard multi-axis parallelism detection procedure.

Example 7

As shown in fig. 6, this embodiment is different from embodiment 1 in that it can be extended for testing the relative angle between reference planes (or between regions of one large reference plane) and applied to the process of machine manufacturing, instrument and equipment assembly, etc. On the reference plane to be measured, an optical flat plate 901 with good parallelism of two surfaces is used to cling to the reference plane to be measured 9, a pentaprism 3 is used to move along a one-dimensional guide rail 2 to the projection range of the reference plane to be measured, each reference plane 9 to be measured is sequentially tested, the standard multi-optical axis parallelism detection flow is referred to for testing, and the angle difference between the actual reference planes is obtained after the test result is divided by 2. The detection precision is mainly limited by the plane precision of the reference plane to be detected. For a reference plane with good plane precision and smoothness, the optical flat 901 can be omitted, and the self-reflection of the reference plane 9 to be tested is directly utilized to realize the test.

Test example:

in order to test the optical axis parallelism of each branch of a laser communication ground terminal with a certain caliber of 1m, the detection equipment developed based on the method provided by the invention has the typical implementation scheme as follows:

the optical axis angle measuring module 1 uses a collimator with a focal length of 1000mm and a caliber of 80mm as a main body, and uses a beam splitting prism with a side length of 30mm as a beam combiner 103. The receiving part for angle measurement adopts an ace 2a4504-5gmBAS as an area array detector, the resolution is 4096×4096, and the pixel size is 2.74um; which emits a collimated beam portion, a different fiber optic output light source can be replaced as needed as the light source 102 for the module using the FC/PC interface.

In order to coaxially calibrate the optical axis angle measurement module 1 with the transmitting and receiving function, a pyramid with a caliber of 50mm and a fused quartz is adopted as the corner reflector 10, the precision is 10 angular seconds, and a pyramid mounting seat is designed at a position 50mm away from the light outlet of the light pipe, so that the pyramid can be manually mounted and dismounted.

The one-dimensional guide rail 2 is a domestic guide rail with the length of 2.2 meters and is provided with a servo motor for carrying out electric movement. Corresponding mechanical structures are designed and manufactured, and all parts of the detection equipment are connected into a whole.

And the pentaprism 3 is made of fused quartz, the effective caliber is 40mm, and the comprehensive angle precision is 5 angular seconds.

In the roll angle test module, the roll angle test module A part 401 adopts a prism with a base angle of 0.8087 degrees, the material is H-K9L, and the caliber is 100mm; the roll angle test module B part 402 uses a prism with a base angle of 1.500 degrees, a material of H-K9L and a caliber of 100mm, and uses a Zygo 4 inch interferometer for testing the wavefront angle of the sub-area, and uses a turn plane mirror to turn the interference detection light path if necessary. For the implementation of calculating the roll, refer to the invention patent 'a roll angle testing device and a test method based on interferometry' which are issued by the company, and the publication number is CN116772750A.

The 1m caliber laser communication ground terminal is tested and comprises 6 transmitting antennas and a receiving antenna, and each antenna is provided with a plurality of optical branches. In the system adjustment process, through the equipment and the method, the parallelism test is carried out on the optical axes of each transmitting antenna and each receiving antenna in sequence, and the optical axis angle of each branch is adjusted or calibrated to be within the 1-angle-second precision range by taking the test result as a guide.

When the device is used for testing the included angle of two plane datum planes with the span of 1.5m in another item, two parallel flat plates are used, the material is fused quartz, the thickness is 10mm, the effective caliber is 80mm, the parallelism of the two surfaces is better than 1 corner second, and the two surfaces are not coated.

Claims (7)

1. The detection equipment for testing the parallelism of multiple optical axes is characterized by comprising an optical axis angle measurement module, a one-dimensional guide rail, a pentaprism and a roll angle test module; the rolling angle testing module consists of a rolling angle testing module A part and a rolling angle testing module B part, wherein the rolling angle testing module A part is fixedly connected with the pentaprism through a mechanical structure and moves along a one-dimensional guide rail together; the rolling angle testing module B part is fixedly connected with the optical axis angle measuring module through a mechanical structure, and the rolling angle testing module B part and the optical axis angle measuring module are fixed in the testing process; the optical axis of the optical axis angle measurement module is parallel to the optical axis of the roll angle test module; the optical axis of the optical axis angle measuring module is vertical to one right angle surface of the pentaprism; at least two branch optical axes of a plurality of optical branches of the device to be tested are perpendicular to the other right-angle surface of the pentaprism.

2. A test device for testing the parallelism of multiple optical axes according to claim 1, characterized in that the pentaprism takes the form of a hollow reflection comprising two reflection planes with an included angle equal to 22.5 degrees.

3. The apparatus of claim 1, wherein the optical axis goniometer module comprises a reflective type including an off-axis parabolic surface and a turning plane mirror.

4. A testing device for testing parallelism of multiple optical axes according to claim 1, wherein the optical axis angle measuring module comprises a light source and a beam combiner, and the light emitted by the light source and the test beam can emit a standard collimated beam through the beam combiner.

5. A testing device for testing parallelism of multiple optical axes according to claim 1, characterized in that at the light outlet of the optical axis angle measurement module, there is provided a corner reflector with its working face facing the optical axis angle measurement module.

6. A detection apparatus for testing multi-axis parallelism according to one of claims 1-5, wherein the roll angle testing module a section comprises a prism a; the roll angle testing module B comprises an interferometer and a prism B; after the parallel light beam emitted by the interferometer is refracted by the prism B, the emitted light beam vertically enters the inclined plane of the prism A, and after being reflected by the inclined plane of the prism A, the light beam returns to the interferometer in an original path for rolling angle test.

7. A detection method for testing multi-axis parallelism, which is based on a detection apparatus for testing multi-axis parallelism as claimed in one of claims 1-6, characterized in that the method comprises the steps of:

s1, selecting two optical branches to be tested in an optical system to be tested, and adjusting the relative spatial position relation between the testing equipment and the optical system to be tested so that the movement track of the pentaprism along the one-dimensional guide rail can cover part of the calibers of the two optical branches to be tested;

s2, enabling the pentaprism to move along the one-dimensional guide rail to a light-emitting beam range of a first optical axis of one optical branch to be detected;

s3, under the condition that the pentaprism is aligned with the optical axis to be measured, simultaneously recording the angle reading of the optical axis angle measurement moduleAnd the reading of the roll angle test module part B +.>；

S4, enabling the pentaprism to move along the one-dimensional guide rail to be within a light-emitting beam range of a second optical axis of the optical branch to be detected;

s5, under the condition that the pentaprism is aligned with the optical axis II, simultaneously recording the angle reading of the optical axis angle measuring moduleAnd the reading of the roll angle test module part B +.>；

S6, calculating and obtaining the angle deviation of the optical axis of the optical branch to be tested relative to the first optical axis of the optical branch to be tested based on the test resultFor the optical axis parallelism error between two optical branches, the calculation formula is as follows:

，

in the calculation formula, small-angle approximation is adopted, and the relative error caused by the approximation is better than one thousandth in a typical angle range of 1 degree; in the 1-angle range, the relative error due to approximation is better than one ten thousandth.