CN108827595B - Detection apparatus based on self-adaptation theory optical system machining error - Google Patents

Abstract

The invention discloses a detection device based on a self-adaptive theoretical optical system processing error, which adopts a point light source to generate a standard plane wave through a beam expanding system, transmits a measured optical system, a beam splitter prism and a phase shifter, takes a variable reflector as a reflection wave surface to obtain interference fringes of the optical system, and obtains uniform interference fringes by controlling the deformation of the variable reflector, wherein the deformation of the reflector is the system processing error of the optical system. The detection device can detect any transmission type optical system and comprises single optical elements such as aspheric surfaces and free-form surfaces. The invention adopts an interferometer as a judgment basis based on a self-adaptive theory, realizes interference fringes through a phase shifter, adopts the accurate control of a controllable deformable reflector to modulate uniform interference fringes, and acquires control information of the reflector to acquire system errors. The invention overcomes the difficulty that the traditional optical system can not measure the system processing error.

Description

Detection apparatus based on self-adaptation theory optical system machining error

Technical Field

The invention belongs to the technical field of optical system error detection, and mainly relates to a processing error detection device for an optical system (comprising a single component, namely an aspheric surface and an optical free-form surface).

Background

With the gradual complexity of an optical imaging system, the final imaging of the optical system and the like caused by the accumulated errors of any machined part have severe examination, so the machining technical requirements of a single device of a product are often improved by designing in the complex optical system, and the machining difficulty and the assembling difficulty are increased invisibly. Most of the existing optical detection devices focus on measurement of parameters of system indexes of the devices, such as resolution, transfer function and the like, errors of corresponding systems are not clear, a wavefront detector is only used for detecting the wavefront of the system, and the wavefront of the system is reversely deduced through the wavefront detection device, so that the total accumulated errors of the optical system cannot be directly obtained, and the compensation of the errors of the system cannot be mentioned. Therefore, it is necessary to measure and compensate the accumulated error of the system for the complicated transmissive optical system with the increase of optical components.

The standard wave surface realizes unequal wave surface reconstruction through an optical system, and the surface type of the part is not regularly distributed, so that the final surface type error accumulation can be approximately seen as the detection of free-form surface errors. Because the optical design and structure of any optical system are different, the uniformity adjustment of the interference fringes can be realized by using the deformable micro-optical reflector to realize the correction of the wave surface error. At present, the detection of the accumulated error of the surface type of the transmission type optical system is not reported, the university of Rochester in the United states adopts a reflection type phase recovery method to obtain the surface type error of a reflecting surface, the method has a simple structure and is easy to realize, but only the detection method is only in a concave shape, and the application of the method is limited; one patent (2011) of an optical free-form surface interference detection device is applied to GaoShishan and the like of Nanjing science and technology university, but the detected surface type is still detected through interference fringes by the technology, the surface type of a single part is detected, and the surface type error of an optical system cannot be detected. The shack-Hartmann wave-front detection method adopted by Singapore W.Guo et al is applied to the detection of a free-form surface, and the method is limited by factors such as the size of a wave-front sensor at present and cannot be widely applied.

Disclosure of Invention

The invention aims to solve the problem that the debugging of all the existing optical systems is difficult because the value of the accumulated error of the optical systems is not known. The invention provides a set of detection device for measuring surface accumulated errors in a transmission type optical system.

The technical scheme of the invention is as follows:

the detection device based on the processing error of the adaptive theoretical optical system is characterized in that: the device comprises a He-Ne laser, a beam expanding system, a beam splitter prism, a standard spherical lens group, a deformable micro-optical reflector, an aperture diaphragm, an imaging lens, a CCD coupling imager, a monitor, a control computer and a phase shifter;

a beam expanding system is arranged behind the He-Ne laser, and expands the laser beam generated by the He-Ne laser into a uniform parallel beam; the detected optical system is coaxially placed behind the beam expanding system; a beam splitter prism is arranged along a light path behind the detected optical system, the light path is divided into two paths through the beam splitter prism, wherein the light path A is that the transmitted beam splitter prism enters a standard spherical lens group, a phase shifter and the standard spherical lens group move along the light path together, a deformable micro-optical reflector is arranged behind the standard spherical lens group, the emergent light of the standard spherical lens group is reflected by the deformable micro-optical reflector back to the standard spherical lens group and then enters the beam splitter prism, and the beam splitter prism is reflected to enter a light path B; the light path B is provided with a diaphragm in the direction of the reflected light of the beam splitter prism, an imaging lens is arranged behind the diaphragm, a CCD coupling imager is arranged behind the imaging lens, the CCD coupling imager is connected with a monitor and a control computer, and the deformable micro-optical reflector is connected with the control computer; the light beam emitted from the optical system to be detected and directly reflected by the beam splitter prism enters the light path B, and the light beam emitted from the optical system to be detected enters the light path A first, and then is reflected by the beam splitter prism to enter the light path B, so that interference fringes are obtained on the CCD coupling imager.

Further preferred scheme, the detection device based on self-adaptation theory optical system processing error is characterized in that: the deformable micro-optical reflector adopts micro-optical devices to realize the precise control of reflector displacement-voltage.

Further preferred scheme, the detection device based on self-adaptation theory optical system processing error is characterized in that: the deformable micro-optical reflector adopts a continuous micro-optical MEMS structure.

Advantageous effects

Compared with the existing optical system error detection means, the invention provides a detection device for detecting the phase of an optical system by adopting the precise controllable deformable micro-optical reflector based on the self-adaptive theory. The advantages are that: (1) the invention adopts the interference fringes as the adjusting basis of the deformable micro-optical reflector, and overcomes the technical limitation of adopting the wave-front detection. (2) The invention can detect the processing error of the light after passing through the lens aiming at all the transmission type optical systems, single lens, free-form surface lens and the like.

Drawings

FIG. 1 is a system configuration diagram of the optical system machining error detecting apparatus of the present invention.

Detailed Description

The invention is described below with reference to specific examples:

the invention relates to an optical system processing error detection device, which comprises a He-Ne laser 1, a beam expanding system 2, a beam splitting prism 4, a standard spherical lens group 5, a deformable micro-optical reflector 6, an aperture diaphragm 7, an imaging lens 8, a CCD coupling imager 9, a monitor 10, a control computer 11 and a phase shifter 12; the beam expanding mechanism 2 adopts a Kepler type telescopic mechanism and consists of a first lens 2-1, a diaphragm 2-2 and a second lens 2-3, the focuses of the first lens 2-1 and the second lens 2-3 are superposed, and the diaphragm is placed on the focuses of the first lens 2-1 and the second lens 2-3.

A beam expanding system 2 is arranged behind the He-Ne laser 1, a detected optical system 3 is arranged behind the beam expanding system 2, a beam splitter prism 4 is arranged behind the optical system, a light path is divided into two paths through the beam splitter prism, one light path is a standard spherical lens group 5 arranged behind the beam splitter prism 4, a phase shifter 12 and the standard spherical lens group 5 do transverse movement together, and a deformable micro-optical reflector 6 is arranged behind the standard spherical lens group 5; the other path of light is that a diaphragm 7 is arranged in the direction of the reflected light of the beam splitter prism 4, an imaging lens 8 is arranged behind the diaphragm 7, a CCD coupling imager 9 is arranged behind the imaging lens 8, the CCD coupling imager 9 is connected with a monitor 10 and a control computer 11, and the deformable micro-optical reflector 6 is connected with the control computer 11.

The invention is characterized in that the design of an interference light path and a controllable deformable reflector ensures that parallel light which is emitted by a light source and passes through a speed expanding system passes through a detected optical system to obtain a wave surface with error information, the obtained wave surface is interfered by a beam splitter prism and the wave surface reflected by the deformable micro-optical reflector, uniform interference fringes are formed by adjusting the deformation of the deformable micro-optical reflector, and the deformation of the deformable micro-optical reflector is the processing error of the optical system.

The present invention will be described in further detail below with reference to the accompanying drawings.

As shown in fig. 1, a beam emitted from a He-Ne laser 1 passes through a beam expanding system 2 (composed of a lens 2-1, a diaphragm 2-2, and a lens 2-3) to form a parallel beam with uniform illumination, and then enters an optical system 3 to be detected, a beam emitted from the optical system passes through a beam splitter 4 and then passes through a standard spherical lens group 5, a part of the beam is converged on a controllable deformable mirror, and the other part of the beam is reflected by the last spherical surface of the standard spherical lens group 5 and then is used as a reference beam. The reference beam reflected by the standard spherical lens group 5 and the surface type error compensation beam reflected by the controllable deformable mirror of the detected wave surface information containing processing errors of the optical system are reflected by the beam splitter prism and enter the aperture diaphragm 7, the imaging lens 8 and the CCD charge coupler 9 to form an interference image acquisition system, and the monitor 10 is used for adjusting a real-time interference image. The phase shifter 12 controls the standard spherical lens group 5 to shift the phase of the residual interference pattern, the computer 11 is used for processing the obtained interference fringes and reversely controlling the deformation of the deformable micro-optical reflector 6, and the final control information of the deformable micro-optical reflector 6 is collected to finally realize the measurement of the processing error of the optical system by monitoring the uniformity of the interference fringes in real time.

Claims (2)

1. The utility model provides a detection device based on self-adaptation theory optical system machining error which characterized in that: the device comprises a He-Ne laser, a beam expanding system, a beam splitter prism, a standard spherical lens group, a deformable micro-optical reflector, an aperture diaphragm, an imaging lens, a CCD coupling imager, a monitor, a control computer and a phase shifter; the deformable micro-optical reflector adopts micro-optical devices to realize the precise control of reflector displacement-voltage;

a beam expanding system is arranged behind the He-Ne laser, and expands the laser beam generated by the He-Ne laser into a uniform parallel beam; the detected optical system is coaxially placed behind the beam expanding system; a beam splitter prism is arranged along a light path behind the detected optical system, the light path is divided into two paths through the beam splitter prism, wherein the light path A is that the transmitted beam splitter prism enters a standard spherical lens group, a phase shifter and the standard spherical lens group move along the light path together, a deformable micro-optical reflector is arranged behind the standard spherical lens group, the emergent light of the standard spherical lens group is reflected by the deformable micro-optical reflector back to the standard spherical lens group and then enters the beam splitter prism, and the beam splitter prism is reflected to enter a light path B; the light path B is provided with a diaphragm in the direction of the reflected light of the beam splitter prism, an imaging lens is arranged behind the diaphragm, a CCD coupling imager is arranged behind the imaging lens, the CCD coupling imager is connected with a monitor and a control computer, and the deformable micro-optical reflector is connected with the control computer; the light beam emitted from the optical system to be detected and directly reflected by the beam splitter prism enters the light path B, and the light beam emitted from the optical system to be detected enters the light path A first, and then is reflected by the beam splitter prism to enter the light path B, so that interference fringes are obtained on the CCD coupling imager.

2. The apparatus for detecting the processing error based on the adaptive theoretical optical system according to claim 1, wherein: the deformable micro-optical reflector adopts a continuous micro-optical MEMS structure.

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