CN109916598A - A method for measuring numerical aperture of microscope objective lens based on diffraction grating - Google Patents
A method for measuring numerical aperture of microscope objective lens based on diffraction grating Download PDFInfo
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- CN109916598A CN109916598A CN201910342715.8A CN201910342715A CN109916598A CN 109916598 A CN109916598 A CN 109916598A CN 201910342715 A CN201910342715 A CN 201910342715A CN 109916598 A CN109916598 A CN 109916598A
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Abstract
一种基于衍射光栅的显微物镜数值孔径测量方法，涉及光学检测领域，尤其涉及显微物镜数值孔径(NA)的测量，包括对液浸及固浸显微物镜NA的测量。它解决了目前测量物镜数值孔径时操作繁琐的问题，还能进一步提高测量精度。所述方法包括，光束通过衍射光栅后发生多缝衍射，经显微物镜后，可在其后焦面处观测到衍射条纹。通过确定衍射条纹位置与后焦面视场边界位置，并根据二者与物镜数值孔径间的函数关系，即可计算得到显微物镜的数值孔径。本发明还可以利用计算机对图像传感器上得到的衍射图像进行识别，实现显微物镜数值孔径的高精度测量。
A method for measuring the numerical aperture of a microscope objective lens based on a diffraction grating relates to the field of optical detection, in particular to the measurement of the numerical aperture (NA) of a microscope objective lens, including the measurement of the NA of a liquid immersion and solid immersion microscope objective. It solves the problem of complicated operation when measuring the numerical aperture of the objective lens at present, and can further improve the measurement accuracy. The method comprises the following steps: after the light beam passes through the diffraction grating, multi-slit diffraction occurs, and after passing through the microscope objective lens, diffraction fringes can be observed at the back focal plane. By determining the position of the diffraction fringes and the boundary position of the field of view of the back focal plane, and according to the functional relationship between the two and the numerical aperture of the objective lens, the numerical aperture of the microscope objective can be calculated. The invention can also use the computer to identify the diffraction image obtained on the image sensor, so as to realize the high-precision measurement of the numerical aperture of the microscope objective lens.
Description
Technical field
The present invention relates to field of optical detection more particularly to a kind of surveys of the microcobjective numerical aperture based on diffraction grating
Amount method.
Background technique
The core component of microscopic system is microcobjective, and the performance of entire microscopic system is determined by microcobjective, and numerical value
Aperture is the important parameter for judging microcobjective performance (resolution ratio, depth of focus, brightness etc.), good numerical aperture measurement method pair
Microcobjective optic-mechanical design and integrated technique etc. are of great significance.
The numerical aperture of measurement object lens mainly uses apertometer at present, and when measurement is mainly seen using human eye
It examines, venter of relicle and observed round spot are tangent on adjusting apertometer, then read data.Whole operation process is all
It is that survey crew completes, the requirement to survey crew is relatively high, and the precision measured is also poor, especially measures higher
When the object lens of NA, it is also necessary to which, by attachment objective, complicated operation, it is difficult to realize automatic detection.Based on total reflection principle
The measurement method of microcobjective numerical aperture is relatively easy, but measuring basis is single, once the position that total reflection absorbs circle occurs
Deviation can produce a very large impact measurement result, and in order to generate total reflection phenomenon, the numerical aperture sheet of microcobjective to be measured
Body must just be wide enough so that incident light meets the angle of excitation total reflection, i.e. total reflection phenomenon is not suitable for low numerical aperture
The measurement of object lens.
The microcobjective numerical aperture measurement method based on diffraction grating that the invention proposes a kind of, collimated light beam pass through light
Diffraction occurs after grid, after the imaging of the microcobjective of finite numerical aperture, can observe diffraction on the focal plane of microcobjective
Striped.By determining diffraction fringe position and back focal plane visual field border position, and according to the letter between the two and numerical aperture of objective
Number relationship, can be calculated the numerical aperture of microcobjective.This method is not only without troublesome operation, but also has the diffraction fringe of plural number
As the measuring basis of plural number, measurement accuracy is improved.
Summary of the invention
(1) technical problems to be solved
The system operatio of traditional measurement microcobjective numerical aperture is cumbersome；Existing method measuring basis is single, measurement knot
Fruit is easy to appear large error.
(2) technical solution
The microcobjective numerical aperture based on diffraction grating that in order to solve the above-mentioned technical problems, the present invention provides a kind of
Non-mechanical detection method, comprising:
Collimated illumination light source, diffraction grating, microcobjective to be measured, imaging lens group.Diffraction grating is placed in micro- object to be measured
It is placed in the conjugate planes of microscope focal plane to be measured on the focal plane of mirror or via imaging lens group, imaging sensor is placed in be measured aobvious
It is placed in the conjugate planes of microscope back focal plane to be measured on the back focal plane of speck mirror or via imaging lens group, in described device,
The collimated light and microcobjective to be measured that collimated illumination light source issues are coaxial, and the collimated light beam that collimated illumination light source issues, which is radiated at, to spread out
It penetrates on grating and diffraction occurs and is imaged in the back focal plane of microcobjective, can get multiorder diffractive striped from imaging sensor；It is logical
It crosses following formula and obtains microcobjective numerical aperture to be measured:
In above formula, NA represents the numerical aperture of microcobjective to be measured；n0Indicate medium between microcobjective and diffraction grating
Refractive index；K represents the series of diffraction fringe, θkRepresent the corresponding angle of diffraction of kth grade diffraction fringe；xmAfter microcobjective to be measured
Maximum ring position on focal plane, xkFor kth grade diffraction fringe position on the microcobjective back focal plane that is obtained on imaging sensor；
Wherein, θkIt can be obtained by the bright line formula of diffraction grating:
In above formula, d represents grating constant, and λ represents lambda1-wavelength.
(3) beneficial effect
Technical solution of the present invention has the advantages that
It is of less demanding to the equipment and operating process of detection microcobjective numerical aperture；
Both the microcobjective of low NA can be measured, and can be used for the liquid leaching of high NA and soaks microcobjective admittedly；
The diffraction fringe of different series is arbitrarily selected, corresponding measurement result, comprehensive multiple measurement results can be obtained
Measurement accuracy can be effectively improved；
The diffraction pattern obtained on imaging sensor can also be identified to realize microcobjective numerical value by computer
The high-precision automatic measuring in aperture.
Detailed description of the invention
Fig. 1 is a kind of schematic diagram of microcobjective numerical aperture measurement method based on diffraction grating of the present invention；
Fig. 2 is in a kind of microcobjective numerical aperture measurement method based on diffraction grating belonging to the present invention, through micro-
The diffraction fringe schematic diagram of object lens imaging；
Fig. 3 is a kind of a kind of specific implementation of microcobjective numerical aperture measurement based on diffraction grating of the present invention
The system schematic of method；
In Fig. 1: 1: incident light 2: diffraction grating 3: microcobjective 4: imaging sensor；
In Fig. 3: 1: collimated illumination light source；2: Amici prism；3: lens 1；4: microcobjective to be measured；5: diffraction grating；6:
Lens 2；7: the system schematic that imaging sensor is diffraction grating in Fig. 3 (a) when being reflective gratings is spread out in Fig. 3 (b)
Penetrate system schematic when grating is transmission grating.
Specific embodiment
With reference to the accompanying drawings and examples, specific embodiments of the present invention will be described in further detail.Following instance
For illustrating the present invention, but it is not intended to limit the scope of the invention.
Specific embodiment 1: illustrating present embodiment in conjunction with the optical path in Fig. 3 (a), and diffraction grating (5) is reflection at this time
Formula grating, a kind of microcobjective numerical aperture methods based on diffraction grating described in present embodiment, it is therefore intended that pass through
The imaging of diffraction effect and microcobjective acts on obtaining the numerical aperture of microcobjective to be measured, it includes: collimated illumination light source
(1)；Amici prism (2)；Lens 1 (3)；Microcobjective (4) to be measured；Diffraction grating (5)；Lens 2 (6)；Imaging sensor (7).
The collimated light beam that the collimated illumination light source (1) issues is after Amici prism (2) and lens 1 (3), by microcobjective to be measured (4)
After being radiated at after convergence on diffraction grating (5), through by microcobjective to be measured (4), lens 1 (3), light splitting rib after diffracted ray reflection
After mirror (2) and lens 2 (6), multiorder diffractive striped is obtained on imaging sensor (7), is obtained by following formula to be measured micro-
Numerical aperture of objective:
In above formula, NA represents the numerical aperture of microcobjective to be measured；n0Indicate medium between microcobjective and diffraction grating
Refractive index；K represents the series of diffraction fringe, θkRepresent the corresponding angle of diffraction of kth grade diffraction fringe；xmAfter microcobjective to be measured
Maximum ring position on focal plane, xkFor kth grade diffraction fringe position on the microcobjective back focal plane that is obtained on imaging sensor；
Wherein, θkIt can be obtained by diffraction grating bright rays formula:
In above formula, d represents grating constant, and λ represents lambda1-wavelength.In this example, as depicted in figs. 1 and 2, it can be used
The ± 1, ± 2 grades of bright lines of diffraction, but in a practical situation, it is not limited to the ± 1, ± 2 grade of bright line of diffraction.
Specific embodiment 2: illustrating present embodiment in conjunction with the optical path in Fig. 3 (b), and diffraction grating (5) is transmission at this time
Formula grating, a kind of microcobjective numerical aperture methods based on diffraction grating described in present embodiment, it is therefore intended that pass through
The imaging of diffraction effect and microcobjective acts on obtaining the numerical aperture of microcobjective to be measured, it includes: collimated illumination light source
(1)；Diffraction grating (5)；Microcobjective (5) to be measured；Imaging sensor (7).The collimated light that the collimated illumination light source (1) issues
After beam is radiated on diffraction grating (5), the diffracted ray of generation is via microcobjective to be measured (4) on imaging sensor (7)
To multiorder diffractive striped, microcobjective numerical aperture to be measured is obtained by the formula in specific embodiment 1.
Claims (1)
1. a kind of microcobjective numerical aperture measurement method based on diffraction grating, which is characterized in that treated using the device
Survey microcobjective carry out numerical aperture measurement, the device include: collimated illumination light source, diffraction grating, microcobjective to be measured,
Imaging sensor, imaging lens group, Amici prism；Diffraction grating is placed on the focal plane of microcobjective to be measured or saturating via imaging
Microscope group is placed in the conjugate planes of microscope focal plane to be measured, imaging sensor be placed on the back focal plane of microcobjective to be measured or via
Imaging lens group is placed in the conjugate planes of microscope back focal plane to be measured, in described device, the collimated light of collimated illumination light source sending
It is coaxial with microcobjective to be measured；
The numerical aperture measurement method, it is further characterized in that, diffraction grating type is transmission-type grating or anti-in the device
Formula grating is penetrated, is one-dimensional grating or two-dimensional grating；
The numerical aperture measurement method, it is further characterized in that: the collimated light beam that collimated illumination light source issues is radiated at diffraction light
Diffraction occurs on grid and is imaged in the back focal plane of microcobjective, can get multiorder diffractive striped from imaging sensor；
The numerical aperture measurement method, it is further characterized in that, microcobjective numerical aperture to be measured is obtained using following formula:
In above formula, NA represents the numerical aperture of microcobjective to be measured；n0Indicate the refraction of medium between microcobjective and diffraction grating
Rate；K represents the series of diffraction fringe, θkRepresent the corresponding angle of diffraction of kth grade diffraction fringe, xmFor microcobjective back focal plane to be measured
On maximum ring position, xkFor kth grade diffraction fringe position on the microcobjective back focal plane that is obtained on imaging sensor, θkIt can
It is obtained by diffraction grating bright rays formula:
In above formula, d represents grating constant, and λ represents lambda1-wavelength.
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Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20070102630A1 (en) * | 2005-08-29 | 2007-05-10 | Canon Kabushiki Kaisha | Method and apparatus for measuring displacement |
| US20100177323A1 (en) * | 2009-01-09 | 2010-07-15 | Canon Kabushiki Kaisha | Wavefront-aberration-measuring device and exposure apparatus |
| CN102116706A (en) * | 2010-01-04 | 2011-07-06 | 上海微电子装备有限公司 | Measurement device and method for numerical aperture of projection objective |
| JP2011257360A (en) * | 2010-06-11 | 2011-12-22 | Canon Inc | Talbot interferometer and adjustment method thereof |
| JP2013108932A (en) * | 2011-11-24 | 2013-06-06 | Canon Inc | Method and apparatus for measuring refractive index distribution |
| CN106802232A (en) * | 2017-03-16 | 2017-06-06 | 北京航空航天大学 | A kind of microcobjective numerical aperture measuring method and system based on total reflection |
| CN106908222A (en) * | 2017-03-15 | 2017-06-30 | 北京航空航天大学 | A kind of measuring method and system of high accuracy microcobjective numerical aperture |
| CN108803248A (en) * | 2018-05-03 | 2018-11-13 | 中国科学院光电研究院 | The on-line measuring device and method of the numerical aperture of projection objective |
| CN109443705A (en) * | 2018-10-25 | 2019-03-08 | 南京大学 | A kind of optical lens numerical aperture measurement method based on calculating imaging |
-
2019
- 2019-04-26 CN CN201910342715.8A patent/CN109916598A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20070102630A1 (en) * | 2005-08-29 | 2007-05-10 | Canon Kabushiki Kaisha | Method and apparatus for measuring displacement |
| US20100177323A1 (en) * | 2009-01-09 | 2010-07-15 | Canon Kabushiki Kaisha | Wavefront-aberration-measuring device and exposure apparatus |
| CN102116706A (en) * | 2010-01-04 | 2011-07-06 | 上海微电子装备有限公司 | Measurement device and method for numerical aperture of projection objective |
| JP2011257360A (en) * | 2010-06-11 | 2011-12-22 | Canon Inc | Talbot interferometer and adjustment method thereof |
| JP2013108932A (en) * | 2011-11-24 | 2013-06-06 | Canon Inc | Method and apparatus for measuring refractive index distribution |
| CN106908222A (en) * | 2017-03-15 | 2017-06-30 | 北京航空航天大学 | A kind of measuring method and system of high accuracy microcobjective numerical aperture |
| CN106802232A (en) * | 2017-03-16 | 2017-06-06 | 北京航空航天大学 | A kind of microcobjective numerical aperture measuring method and system based on total reflection |
| CN108803248A (en) * | 2018-05-03 | 2018-11-13 | 中国科学院光电研究院 | The on-line measuring device and method of the numerical aperture of projection objective |
| CN109443705A (en) * | 2018-10-25 | 2019-03-08 | 南京大学 | A kind of optical lens numerical aperture measurement method based on calculating imaging |
Non-Patent Citations (2)
| Title |
|---|
| F.LEI、L.K.DANG: "Measurement of the numerical aperture and f-number of a lens system by using a phase grating", 《TECHNICAL NOTE》 * |
| 刘志祥 等: "大数值孔径物镜的波像差测量及其特殊问题", 《光学精密工程》 * |
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