CN115628686A - High-precision light spot testing system and method based on space imaging system - Google Patents

High-precision light spot testing system and method based on space imaging system Download PDF

Info

Publication number
CN115628686A
CN115628686A CN202211181737.9A CN202211181737A CN115628686A CN 115628686 A CN115628686 A CN 115628686A CN 202211181737 A CN202211181737 A CN 202211181737A CN 115628686 A CN115628686 A CN 115628686A
Authority
CN
China
Prior art keywords
lens
beam splitter
sample
image
light
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202211181737.9A
Other languages
Chinese (zh)
Inventor
陈力锋
胡紫阳
颜扬捷
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Jiangsu Niobium Ao Photoelectric Technology Co ltd
Original Assignee
Jiangsu Niobium Ao Photoelectric Technology Co ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Jiangsu Niobium Ao Photoelectric Technology Co ltd filed Critical Jiangsu Niobium Ao Photoelectric Technology Co ltd
Priority to CN202211181737.9A priority Critical patent/CN115628686A/en
Priority to PCT/CN2022/126157 priority patent/WO2024065898A1/en
Publication of CN115628686A publication Critical patent/CN115628686A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B11/00—Measuring arrangements characterised by the use of optical techniques
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B11/00—Measuring arrangements characterised by the use of optical techniques
    • G01B11/26—Measuring arrangements characterised by the use of optical techniques for measuring angles or tapers; for testing the alignment of axes
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M11/00—Testing of optical apparatus; Testing structures by optical methods not otherwise provided for
    • G01M11/02—Testing optical properties
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M11/00—Testing of optical apparatus; Testing structures by optical methods not otherwise provided for
    • G01M11/02—Testing optical properties
    • G01M11/0207—Details of measuring devices
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/48—Laser speckle optics

Abstract

The invention provides a high-precision light spot testing system and method based on a space imaging system, wherein the system comprises: the device comprises a wide-spectrum light source, an optical fiber, a light source focusing lens, a Kohler lens, a beam splitter, a high-magnification objective lens, a sample, a six-axis objective table, a Fourier lens, an iris diaphragm, a secondary focusing lens, an imaging lens, a variable neutral density optical filter, a CCD camera and a computer. During testing, a sample is placed on a high-precision six-axis platform, a light outlet is found by a method of forming a reflected real image of the sample by using wide-spectrum illumination light, then a far-field image of a luminous spot of the sample is projected onto a camera through Fourier imaging, and finally data processing is carried out on the image to obtain a divergence angle of the luminous spot of the sample and then the size of the luminous spot is calculated. The invention is widely applicable to the light spot measurement of micron-scale light-emitting elements, such as optical fibers, lasers, optical chips and the like, the measurement error is within 5 percent, and the test wavelength can cover visible light to near-infrared wave bands.

Description

High-precision light spot testing system and method based on space imaging system
Technical Field
The invention belongs to the technical field of optics and optical communication, and particularly relates to a high-precision light spot testing system and method for a space imaging system.
Background
In recent years, the development of 5G communication has driven the rapid upgrade of optical communication technology, and the challenge comes with it, especially in terms of energy consumption and performance. In optical communications, a portion of the energy loss originates at the optical switching interface. The mode fields of light in different material media are different in size, so that the emergent light spots are not matched in mode during energy exchange, and part of light becomes stray light, so that the coupling efficiency is low, the system energy consumption is increased, and the signal to noise ratio of communication is reduced. The ability to accurately measure the excident light spot of the structure would be of great help to further improve the coupling efficiency of the optical interface through engineering design. However, in the prior art, the size of the emergent light spot is difficult to accurately obtain, and the reason is that the emergent light spot is generally caused by two reasons:
on one hand, the designed structure emergent light spot is different from the prepared structure emergent light spot due to the reasons of materials, processes, environments and the like.
On the other hand, the actual excident spot size has no direct relationship with the size of the excident end face, which means that the exact size of the excident spot cannot be determined by merely observing the near-field spot and the end face. However, there is no precise measurement scheme.
Disclosure of Invention
In order to solve the problems, the invention provides a high-precision light spot testing system and method based on a space imaging system, which are widely applied to measuring the light spot size of a light-emitting element with a micrometer scale.
In order to achieve the purpose, the technical scheme of the invention is as follows:
a high-precision light spot testing method based on a space imaging system comprises the following steps:
step 1, selecting proper parameters
The selection parameter satisfies 2f O tan(sin -1 NA)f C /f F <L X ,2f O tan(sin -1 NA)f C /f F <L Y Wherein f is a positive power of the Fourier lens, and an imaging lens O Is the equivalent focal length of the high power objective lens, NA is the numerical aperture of the high power objective lens, f C Is the focal length of the imaging lens, f F Is the focal length of the Fourier lens, L X Horizontal dimension of CCD camera, L Y The maximum diameter of a focal plane image behind an objective lens is limited within a CCD receiving range for the vertical size of a CCD camera; real image magnification (f) C ·f F )/(f I ·f O ) The projection area of the sample to be detected on the CCD is smaller than the area of the CCD after the sample to be detected is amplified;
step 2, installing and calibrating the test system
When the system comprises a Kohler lens, an iris diaphragm and a secondary focusing lens, the following processes are included:
the method comprises the following steps of building a test system, connecting an optical fiber with a light source, sequentially arranging a light source focusing lens and a beam splitter on a light path led in by the optical fiber from near to far, arranging a high-magnification objective lens and a six-axis objective table on a reflection light path of the beam splitter, sequentially arranging a Fourier lens, a secondary focusing lens, an imaging lens, a variable neutral density filter and a CCD camera on a transmission light path of the beam splitter from near to far, and connecting the CCD camera with a computer; loading a silver reflector on a six-axis objective table, wherein the optical path direction is in the order of an optical fiber, a light source focusing lens, a beam splitter, a high-magnification objective lens, a silver reflector, a high-magnification objective lens, a beam splitter, a Fourier lens, a secondary focusing lens, an imaging lens, a variable neutral density filter and a CCD camera; adjusting the distance between the objective lens and the objective table to make the computer display the image as a reflector surface focusing image; removing the secondary focusing lens; adjusting the variable neutral density filter to enable the maximum value of the image brightness obtained by the computer to be close to saturation; recording the image and measuring the image brightness 1/e 2 The width in the horizontal direction and the width in the vertical direction are respectively X 1 Pixel and Y 1 A pixel;
when the system does not comprise a Kohler lens, an iris diaphragm and a secondary focusing lens, the following processes are included:
setting up a test system without setting FourierA leaf lens; connecting an optical fiber with a light source, sequentially arranging a light source focusing lens and a beam splitter on a light path led by the optical fiber from near to far, arranging a high-magnification objective lens and a six-axis objective table on a reflected light path of the beam splitter, sequentially arranging an imaging lens, a variable neutral density filter and a CCD camera on a transmission light path of the beam splitter from near to far, and connecting the CCD camera with a computer; loading a silver reflector on a six-axis objective table, wherein the light path direction is in the order of an optical fiber, a light source focusing lens, a beam splitter, a high-magnification objective lens, the silver reflector, the high-magnification objective lens, the beam splitter, an imaging lens, a variable neutral density optical filter and a CCD camera; adjusting the distance between the objective lens and the objective table to make the computer display the image as a reflector surface focusing image; adding a Fourier lens between the beam splitter and the imaging lens; adjusting the variable neutral density filter to enable the maximum value of the image brightness obtained by the computer to be close to saturation; recording the image and measuring the image brightness 1/e 2 The width in the horizontal direction and the width in the vertical direction are respectively X 1 Pixel and Y 1 A pixel;
step 3, testing the sample
When the system comprises a Kohler lens, an iris diaphragm and a secondary focusing lens, the following processes are included:
loading a sample to be tested on a sample table, building a test system, connecting an optical fiber with a light source, sequentially arranging a light source focusing lens, a Kohler lens and a beam splitter on a light path led by the optical fiber from near to far, arranging a high-magnification objective lens and a six-axis objective table on a reflection light path of the beam splitter, sequentially arranging a Fourier lens, a secondary focusing lens, an imaging lens, a variable neutral density filter and a CCD camera on a transmission light path of the beam splitter from near to far, arranging an iris diaphragm between the Fourier lens and the secondary focusing lens, enabling the light path to pass through a hole in the iris diaphragm, and connecting the CCD camera with a computer; the light path direction is according to the order of an optical fiber, a light source focusing lens, a Kohler lens, a beam splitter, a high-magnification objective lens, a sample to be detected, a high-magnification objective lens, a beam splitter, a Fourier lens, an iris diaphragm, a secondary focusing lens, an imaging lens, a variable neutral density optical filter and a CCD camera; adjusting the distance between the stage and the objective lens to make the computer display the image as the reflection of the sample surfaceAn image; positioning the position near the light emergent part of the sample by a reflected real image; enabling a sample to be self-luminous, removing a beam splitter in an optical path, and changing the direction of the optical path into the sample to be detected, a high-magnification objective lens, a Fourier lens, an iris diaphragm, a secondary focusing lens, an imaging lens, a variable neutral density optical filter and a CCD camera; further moving the sample to center and focus the light spot seen by the CCD camera; changing the size of the iris diaphragm to limit the imaging range to be only near the facula; removing the secondary focusing lens, and adjusting the variable neutral density filter to ensure that the maximum brightness value of the image obtained by the computer is the same as that of the calibration image; recording the image and measuring the image brightness 1/e 2 The width in the horizontal direction and the width in the vertical direction are respectively X 2 Pixel and Y 2 A pixel;
when the system does not comprise a Kohler lens, an iris diaphragm and a secondary focusing lens, the following processes are included:
loading a sample to be detected on a sample table, wherein no Fourier lens is arranged; connecting an optical fiber with a light source, sequentially arranging a light source focusing lens and a beam splitter on a light path led by the optical fiber from near to far, arranging a high-magnification objective lens and a six-axis objective table on a reflected light path of the beam splitter, sequentially arranging an imaging lens, a variable neutral density filter and a CCD camera on a transmission light path of the beam splitter from near to far, and connecting the CCD camera with a computer; the light path direction is according to the order of the optical fiber, the light source focusing lens, the beam splitter, the high-magnification objective lens, the sample to be detected, the high-magnification objective lens, the beam splitter, the imaging lens, the variable neutral density optical filter and the CCD camera; adjusting the distance between the objective lens and the objective table to enable the computer to present an image as a sample surface reflection real image; positioning the vicinity of the light emergent part of the sample through a reflected real image; enabling the sample to be self-luminous, removing a beam splitter in an optical path, and changing the direction of the optical path into the sample to be detected, a high-magnification objective lens, an imaging lens, a variable neutral density optical filter and a CCD camera; further moving the sample to center and focus the light spot seen by the CCD camera; adding a fourier lens between the beam splitter and the imaging lens; adjusting the variable neutral density filter to ensure that the maximum brightness value of the image obtained by the computer is the same as that of the calibration image; recording the image and measuring the image brightness 1/e 2 In the horizontal direction and the vertical directionAre each X 2 Pixel and Y 2 A pixel;
step 4, data processing
By comparing the calibration data with the reference measurement data, the horizontal divergence angle of the sample is calculated as
Figure BDA0003867090290000031
Corresponding to Gaussian spot having horizontal diameter of
Figure BDA0003867090290000032
A vertical divergence angle of
Figure BDA0003867090290000033
Corresponding to a Gaussian spot having a vertical diameter of
Figure BDA0003867090290000034
Further, the method also comprises the following steps: and measuring the size of the far-field image of the sample to be measured according to the intensity distribution diagram of the Fourier image of the sample.
The invention also provides a high-precision light spot testing system based on the space imaging system, which comprises a wide-spectrum light source, an optical fiber, a light source focusing lens, a beam splitter, a high-magnification objective lens, a six-axis objective table, a Fourier lens, an imaging lens, a variable neutral density optical filter, a CCD camera and a computer, wherein the wide-spectrum light source is arranged on the optical fiber;
the wide-spectrum light source is connected with an optical fiber, the light source focusing lens and the beam splitter are sequentially arranged on a light path led by the optical fiber from near to far, the high-magnification objective lens and the six-axis objective table are arranged on a reflection light path of the beam splitter, the Fourier lens, the imaging lens, the variable neutral density optical filter and the CCD camera are sequentially arranged on a transmission light path of the beam splitter from near to far, and the CCD camera is connected with a computer;
the optical fiber introduces light of a wide-spectrum light source into the system; the light source focusing lens is used for collimating light emitted by the wide-spectrum light source through the optical fiber; the beam splitter is used for combining the reflection light path and the transmission light path into one path in front of the objective lens; the high-magnification objective lens is used for collecting light in all emission directions of a sample to be detected; the six-axis objective table is used for loading a sample to be tested; the Fourier lens is used for focusing a rear focal plane image behind the objective lens and carrying out optical Fourier transform on the near-field light spot to obtain a far-field image corresponding to the near-field light spot; the imaging lens is used for enabling a CCD camera to form a focusing real image; the variable neutral density filter is used for reducing the light transmission quantity; and the computer is used for receiving and processing the CCD camera image.
Further, the device also comprises a Kohler lens, an iris diaphragm and a secondary focusing lens;
the Kohler lens is arranged between the light source focusing lens and the beam splitter, the iris diaphragm and the secondary focusing lens are arranged between the Fourier lens and the imaging lens and are positioned on a transmission light path of the beam splitter, the iris diaphragm is positioned at the position where the back focal point of the Fourier lens is overlapped with the front focal point of the secondary focusing lens, and the transmission light path penetrates through a hole in the iris diaphragm;
the Kohler lens is used for forming a Kohler illumination system in front of the objective lens to enlarge the illumination range of the objective lens; the variable diaphragm is used for filtering stray light; the secondary focusing lens is used for focusing the back focal plane image of the Fourier lens, and real-imaging the wave front at the position of the iris diaphragm, so that the filtering range is convenient to adjust.
Further, the light source focusing lens, the Kohler lens, the Fourier lens, the secondary focusing lens and the imaging lens are all aspheric lenses, the lenses are coated with antireflection films with corresponding wavelengths on two sides, and the diameters of the lenses are not less than 1 inch and not more than 2 inches; the parameters of the high-power objective lens, the Fourier lens and the imaging lens should satisfy 2f O tan(sin -1 NA)f C /f F <L X ,2f O tan(sin - 1 NA)f C /f F <L Y Where Lx and Ly are the transverse and longitudinal dimensions of the CCD, respectively.
Further, the parameter to be measured of the sample to be measured is the divergence angle theta<sin -1 NA。
Furthermore, the beam splitter is a film beam splitter or a body beam splitter, antireflection films with corresponding wavelengths are plated on two sides of the beam splitter, the splitting ratio is 50, and the beam splitter is used for combining a reflection light path and a transmission light path into one path in front of an objective lens.
Furthermore, the magnification M of the high-magnification objective lens is not less than 40 times, the numerical aperture NA is not less than 0.5 and less than 1, and the surface of the high-magnification objective lens is plated with an anti-reflection film with corresponding wavelength.
Furthermore, the variable range of the aperture of the iris diaphragm is 0.1 mm to 10 mm, and the iris diaphragm is used for filtering stray light in a spatial filtering mode to improve the signal-to-noise ratio of the test.
Further, the wide-spectrum light source is a halogen lamp, and the wavelength of the halogen lamp covers visible light to near infrared; the optical fiber is typically a multimode optical fiber having a diameter of less than 1 mm; the variable neutral density filter has a neutral density variable range of 0.1 to 4.
The beneficial effects of the invention are as follows:
1. the invention deduces the accurate Gaussian spot size by measuring the far-field divergence angle of the light spot emitted by the device to be measured, and solves the problems of larger light spot measurement result error, complex measuring instrument (a method for moving by using a mechanical arm) and the like caused by the fact that the waist position of the Gaussian beam cannot be accurately positioned in the prior art.
2. The test system has high degree of freedom and large measurement range, can meet the characteristics of a sample to be tested by adjusting corresponding measurement parameters, has the measured light spot size range from sub-millimeter to submicron, has the wavelength range from visible light to near infrared wave band, and is far beyond the prior art means.
3. The invention is widely suitable for the light spot measurement of a light-emitting element with a micron scale, can be applied to active optical devices such as a laser and a superluminescent light-emitting diode and passive optical devices such as an optical fiber, an optical waveguide and an optical chip, has a measurement error within 5 percent, and has wide application value for scientific research and engineering research and development related to optics.
Drawings
Fig. 1 is a schematic diagram of a light path assembly in a high-precision light spot testing system based on a spatial imaging system provided by the invention.
Fig. 2 is a schematic diagram of optical path parameters in a high-precision light spot testing system based on a spatial imaging system provided by the invention.
FIG. 3 is a schematic diagram of a silver mirror calibrated to obtain a Fourier image on a CCD by reflected light, X, of a system before testing according to the present invention 1 And Y 1 Corresponding to 1/e of horizontal and vertical directions of image 2 Width.
FIG. 4 is a schematic diagram of a real image of a sample (illustrated as a small mode field fiber) obtained by reflecting light onto a CCD according to the present invention during sample testing.
FIG. 5 is a schematic diagram of the present invention for obtaining a Fourier image of a sample (illustrated as a small mode field fiber) upon sample testing by self-illumination on a CCD, X 2 And Y 2 Corresponding to 1/e of horizontal and vertical directions of image 2 Width.
FIG. 6 is a schematic diagram of the intensity distribution (horizontal or vertical) of the Fourier image of the sample (mirror and small mode field fiber) obtained by the present invention when the sample is tested, and the size of the far field image of the sample to be tested can be accurately measured by the diagram.
Description of the reference numerals:
1-wide spectrum light source, 2-optical fiber, 3-light source focusing lens, 4-kohler lens, 5-beam splitter, 6-high magnification objective lens, 7-sample, 8-six-axis objective table, 9-Fourier lens, 10-iris diaphragm, 11-secondary focusing lens, 12-imaging lens, 13-variable neutral density filter, 14-CCD camera, 15-computer, f S Focal length of the light source focusing lens, f K Focal length of Kohler lens, f F Focal length of Fourier lens, f I Focal length of the secondary focusing lens, f C Focal length of imaging lens, D 1 -any distance greater than 0, D 2 -any distance greater than 0.
Detailed Description
The technical solutions provided by the present invention will be described in detail below with reference to specific examples, and it should be understood that the following specific embodiments are only illustrative of the present invention and are not intended to limit the scope of the present invention.
As shown in fig. 1-2, the present invention provides a high-precision spot testing system based on a spatial imaging system. The test object aimed at in this example is a small mode field fiber, and the system structure includes: the device comprises a wide-spectrum light source 1, an optical fiber 2, a light source focusing lens 3, a Kohler lens 4, a beam splitter 5, a high-magnification objective lens 6, a six-axis objective table 8, a Fourier lens 9, an iris diaphragm 10, a secondary focusing lens 11, an imaging lens 12, a variable neutral density filter 13, a CCD camera 14 and a computer 15. The system uses corresponding test logic method to realize the whole test.
Specifically, the broad spectrum light source in this example is a halogen lamp with a wavelength covering visible light to near infrared (300 nm to 2 μm), and the broad spectrum light source is a light source for light emission in calibration of the system and for illumination in measurement of the sample.
The fiber is a multimode fiber with a diameter of 200 microns (typically less than 1 mm) that directs the light from a broad spectrum source into the system as the starting point for the entire light path.
The light source focusing lens 3, the Kohler lens 4, the Fourier lens 9, the secondary focusing lens 11 and the imaging lens 12 are all aspheric lenses, the wavelength of the lens with double-sided antireflection coating is 1050-1700 nm (alternatively, 400-700 nm or 650-1050 nm), the lens diameter is 1 inch (preferably, not less than 1 inch and not more than 2 inches), the light source focusing lens 3 is used for collimating light emitted by a wide-spectrum light source through an optical fiber, the Kohler lens 4 is used for forming a Kohler illumination system in front of an objective lens, the illumination range of the objective lens is enlarged, and a sample is convenient to search, the Fourier lens 9 is used for focusing a back focal plane image behind the objective lens, and performs optical Fourier transformation on a near-field light spot to obtain a corresponding far-field image, the secondary focusing lens 11 is used for focusing the back focal plane image of the Fourier lens 9, a wave front plane at a position of a variable diaphragm is imaged in real image, and the filtering range is convenient to adjust, the imaging lens is used for focusing a real image on a CCD, in the present example, the focal lengths f of the light source focusing lens 3, the Kohler lens 4, the Fourier lens 9, the Fourier lens 11, the imaging lens 12 and the imaging lens 12 are f S =50 mm, f K =200 mm, f F =150 mm, f I =50 mm, f C =300 mm. The focal lengths are merely examples, and the focal lengths of the lenses may be selected as desired.
The beam splitter 5 is a film beam splitter or a body beam splitter, and is coated with antireflection films of 1200 nm-1600 nm on both sides, and the beam splitting ratio of the beam splitter in this example is 50.
The high-magnification objective 6 has the function of collecting light in all emission directions of a sample to be detected as much as possible by utilizing the characteristic of high NA, and focusing the light with a specific angle to the corresponding position of the back focal plane of the objective through optical Fourier transform, so that the position-light intensity distribution graph of a near-field image is converted into the angle-light intensity distribution graph of a far-field image, and the purpose of analyzing the divergence angle of a light spot is achieved. The magnification M of the high-power objective lens 6 is not less than 40 times, the numerical aperture NA is not less than 0.5 and less than 1, and the surface of the high-power objective lens is plated with an antireflection film with corresponding wavelength (400-700 nm, 650-1050 nm or 1050-1700 nm). In this example, the high-power objective lens 6 has a magnification of 40 times and an equivalent focal length f O =2 mm, numerical aperture NA 0.5, and anti-reflection film with 1050-1700 nm plated on the surface.
The six-axis objective table 8 is used for loading a sample to be measured, the six-axis freedom degree of the six-axis objective table corresponds to a vertical coordinate axis and a rotating coordinate axis in a Cartesian coordinate system, and fine adjustment precision of the linear direction and the rotating direction of the objective table is not lower than 1 micrometer/scale and 1 minute/scale respectively.
In this example, the sample to be measured is a small mode field optical fiber, and the parameter to be measured is defined as the divergence angle theta<sin -1 NA, center wavelength of operation λ.
The variable aperture range of the iris diaphragm 10 is 0.1 mm to 10 mm, and the iris diaphragm has the function of filtering out stray light in a spatial filtering mode to improve the signal-to-noise ratio of the test. When the test system is installed, the iris 10 is located at the coincidence of the back focal point of the fourier lens and the front focal point of the secondary focusing lens.
The variable neutral density filter 13 has a neutral density variable range of 0.1 to 4. The functions are to reduce the amount of light passing, prevent the CCD camera 14 from being damaged by receiving excessively high energy, and uniformize the brightness of the image.
The CCD camera 14 is optimized for a specific wavelength, has a working range of 900 nm to 2000 nm, a dynamic range of more than 30dB, a resolution of horizontal X pixels to vertical Y pixels, which should be more than 300 to 200, in this example, a resolution of 400 to 300, and a CCD size of L X *L Y And 9 mm (= 12 mm). CCD camera for capturing the proximity of a sample to be measuredA field image and a far field image.
The computer 15 is connected to the CCD camera 14, and can be equipped with control and image capturing software adapted to the CCD camera, and can output images for post-processing.
The invention also provides a high-precision light spot testing method based on the space imaging system, which comprises the following steps:
step 1, selecting proper parameters
The parameters of the high-power objective lens, the Fourier lens and the imaging lens are selected to satisfy 2f O tan(sin -1 NA)f C /f F <L X ,2f O tan(sin -1 NA)f C /f F <L Y The purpose is to limit the maximum diameter of the focal plane image behind the objective lens within the CCD receiving range; (f) C ·f F )/(f I ·f O ) For real image magnification, the projection area of the sample to be measured on the CCD after being amplified is smaller than the area of the CCD.
Step 2, installing and calibrating the test system
The system was set up as shown in fig. 1 and placed with the optical elements in the positions shown in fig. 2, without the kohler lens 4. The optical fiber 2 is connected with a light source, light of the light source is led into the system, the light source focusing lens 3 and the beam splitter 5 are sequentially arranged on a light path led by the optical fiber from near to far, the high-magnification objective lens 6 and the six-axis objective table 8 are arranged on a reflected light path of the beam splitter 5, the Fourier lens 9, the secondary focusing lens 11, the imaging lens 12, the variable neutral density filter 13 and the CCD camera 14 are sequentially arranged on a transmission light path of the beam splitter 5 from near to far, and the CCD camera 14 is connected with a computer. The silver mirror was loaded on the six-axis stage 8. The light source is turned on, and as shown in fig. 2, the optical path direction is in the order of the optical fiber 2, the light source focusing lens 3, the beam splitter 5, the high-power objective lens 6, the silver mirror, the high-power objective lens 6, the beam splitter 5, the fourier lens 9, the secondary focusing lens 11, the imaging lens 12, the variable neutral density filter 13, and the CCD camera 14. Adjusting the distance between the objective lens and the objective table to make the computer display the image as a reflector surface focusing image; removing the secondary focusing lens 11; adjusting the variable neutral density filter 13 to brighten the image obtained by the computerThe degree maximum is close to saturation, as shown in fig. 3; recording the image and measuring the image brightness 1/e 2 The width in the horizontal direction and the width in the vertical direction are respectively X 1 Pixel and Y 1 A pixel.
The purpose of the pre-test system calibration is to determine the maximum ranges X1 and Y1 of the divergence angle test, and to calculate and determine the per-pixel angular precision sin -1 (NA/X 1 ) And sin -1 (NA/Y 1 )。
Step 3, testing the sample
Loading a sample 7 to be tested to a sample stage through a small mode field optical fiber, building a system as shown in figure 1, connecting an optical fiber 2 with a light source, introducing light of the light source into the system, sequentially arranging a light source focusing lens 3, a Kohler lens 4 and a beam splitter 5 on a light path introduced by the optical fiber from near to far, arranging a high-magnification objective lens 6 and a six-axis objective stage 8 on a reflection light path of the beam splitter 5, sequentially arranging a Fourier lens 9, a secondary focusing lens 11, an imaging lens 12, a variable neutral density optical filter 13 and a CCD camera 14 on a transmission light path of the beam splitter 5 from near to far, arranging an iris diaphragm 10 between the Fourier lens 9 and the secondary focusing lens 11, enabling the light path to pass through a hole on the iris diaphragm 10, and connecting the CCD camera 14 with a computer. As shown in fig. 2, the optical path direction is in the order of an optical fiber 2, a light source focusing lens 3, a kohler lens 4, a beam splitter 5, a high-power objective lens 6, a sample to be measured 7, the high-power objective lens 6, the beam splitter 5, a fourier lens 9, an iris 10, a secondary focusing lens 11, an imaging lens 12, a variable neutral density filter 13, and a CCD camera 14. Adjusting the distance between the objective lens and the objective table to enable the computer to present an image as a sample surface reflection real image; positioning the vicinity of the light-emitting part of the sample by reflecting the real image, as shown in fig. 4; the sample is made to self-illuminate, a beam splitter 5 in the light path is removed (a folding beam splitter can be adopted, and the effect of removing the beam splitter from the light path can be achieved by only folding the beam splitter), and the direction of the light path is changed into a sample to be measured 7, a high-magnification objective lens 6, a Fourier lens 9, an iris diaphragm 10, a secondary focusing lens 11, an imaging lens 12, a variable neutral density filter 13 and a CCD camera 14; further moving the sample to center and focus the light spot seen by the CCD camera; changing the size of the iris diaphragm to limit the imaging range to be only near the facula; removingA secondary focusing lens 11 for adjusting the variable neutral density filter to make the maximum brightness value of the image obtained by the computer the same as the calibration image; recording the image and measuring the image brightness 1/e 2 The width in the horizontal direction and the width in the vertical direction are respectively X 2 Pixel and Y 2 Pixel as shown in fig. 5.
Step 4, data processing
By comparing the calibration data with the reference measurement data, the horizontal direction divergence angle of the sample is calculated to be
Figure BDA0003867090290000081
Corresponding to a Gaussian spot having a horizontal diameter of
Figure BDA0003867090290000082
A vertical divergence angle of
Figure BDA0003867090290000083
Corresponding to a Gaussian spot having a vertical diameter of
Figure BDA0003867090290000084
The intensity distribution (horizontal or vertical) of the fourier image of the sample obtained by taking a picture with a CCD camera is shown in fig. 6, from which the size of the far-field image of the sample to be measured can be accurately measured.
Through the trial and error, the aforesaid high accuracy facula test system based on space imaging system can structurally retrench, and the structure includes: the device comprises a wide-spectrum light source 1, an optical fiber 2, a light source focusing lens 3, a beam splitter 5, a high-magnification objective lens 6, a six-axis objective table 8, a Fourier lens 9, an imaging lens 12, a variable neutral density filter 13, a CCD camera 14 and a computer 15. The system uses corresponding test logic method to realize the whole test. Namely, the kohler lens 4, the variable diaphragm 10 and the secondary focusing lens 11 in the system are removed, and the rest of the building modes of the components are still referred to fig. 1 and fig. 2. The simplified system can also measure the size of a light spot, but the difficulty of finding a target by removing the Kohler lens is increased, the measurement process can be interfered by stray light, and the operation difficulty and the measurement error are greatly increased compared with a test system with all components.
Based on the simplified high-precision light spot testing system, the corresponding testing method is also simplified. Specifically, the invention provides a light spot testing method based on a simplified high-precision light spot testing system, wherein the steps 1 and 4 are the same as the steps 1 and 4 in the high-precision light spot testing method based on the space imaging system, and the steps 2 and 3 are as follows:
step 2, installing and calibrating the test system
The system is set up as shown in figure 1, and the optical elements are arranged according to the positions shown in figure 2, and the Kohler lens 4, the Fourier lens 9, the iris diaphragm 10 and the secondary focusing lens 11 are not arranged at this time. The optical fiber 2 is connected with a light source, the light of the light source is introduced into the system, the light source focusing lens 3 and the beam splitter 5 are sequentially arranged on a light path introduced by the optical fiber from near to far, the high-magnification objective lens 6 and the six-axis objective table 8 are arranged on a reflection light path of the beam splitter 5, the imaging lens 12, the variable neutral density filter 13 and the CCD camera 14 are sequentially arranged on a transmission light path of the beam splitter 5 from near to far, and the CCD camera 14 is connected with a computer. The silver mirror was loaded on the six-axis stage 8. The light source is turned on, and as shown in fig. 2, the optical path direction is in the order of the optical fiber 2, the light source focusing lens 3, the beam splitter 5, the high-magnification objective lens 6, the silver mirror, the high-magnification objective lens 6, the beam splitter 5, the imaging lens 12, the variable neutral density filter 13, and the CCD camera 14. Adjusting the distance between the objective lens and the objective table to make the computer display the image as a reflector surface focusing image; a fourier lens 9 is added between the beam splitter and the imaging lens; adjusting the variable neutral density filter 13 to make the maximum value of the image brightness obtained by the computer approach to saturation; recording the image and measuring the image brightness 1/e 2 The width in the horizontal direction and the width in the vertical direction are respectively X 1 Pixel and Y 1 A pixel.
The purpose of the pre-test system calibration is to determine the maximum ranges X1 and Y1 of the divergence angle test, and to calculate and determine the per-pixel angular precision sin -1 (NA/X 1 ) And sin -1 (NA/Y 1 )。
Step 3, testing the sample
A sample 7 to be tested is loaded on a sample stage by a small mode field optical fiber,at this time, the kohler lens 4, the variable diaphragm 10, the secondary focusing lens 11 and the fourier lens 9 are not arranged, the optical fiber 2 is connected with the light source, the light of the light source is introduced into the system, the light source focusing lens 3 and the beam splitter 5 are sequentially arranged on a light path introduced by the optical fiber from near to far, the high-magnification objective lens 6 and the six-axis objective table 8 are arranged on a reflection light path of the beam splitter 5, the imaging lens 12, the variable neutral density filter 13 and the CCD camera 14 are sequentially arranged on a transmission light path of the beam splitter 5 from near to far, and the CCD camera 14 is connected with the computer. As shown in fig. 2, the optical path direction is in the order of an optical fiber 2, a light source focusing lens 3, a beam splitter 5, a high-power objective lens 6, a sample to be measured 7, the high-power objective lens 6, the beam splitter 5, an imaging lens 12, a variable neutral density filter 13, and a CCD camera 14. Adjusting the distance between the objective lens and the objective table to enable the computer to present an image as a sample surface reflection real image; positioning the vicinity of the light emergent part of the sample through a reflected real image; the sample is self-luminous, the beam splitter 5 in the light path is removed (a folding beam splitter can be adopted, and the effect of removing the beam splitter from the light path can be achieved by only folding the beam splitter), and the direction of the light path is changed into a sample 7 to be detected, a high-magnification objective lens 6, an imaging lens 12, a variable neutral density filter 13 and a CCD camera 14; further moving the sample to center and focus the light spot seen by the CCD camera; a fourier lens 9 is added between the beam splitter and the imaging lens; adjusting the variable neutral density filter to ensure that the maximum value of the image brightness obtained by the computer is the same as the calibration image; recording the image and measuring the image brightness 1/e 2 The width in the horizontal direction and the width in the vertical direction are respectively X 2 Pixel and Y 2 Pixel, as shown in fig. 5.
It should be noted that the above-mentioned contents only illustrate the technical idea of the present invention, and the protection scope of the present invention is not limited thereby, and it is obvious to those skilled in the art that several modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations fall within the protection scope of the claims of the present invention.

Claims (10)

1. A high-precision light spot testing method based on a space imaging system is characterized by comprising the following steps:
step 1, selecting proper parameters
The selection parameter satisfies 2f O tan(sin -1 NA)f C /f F <L X ,2f O tan(sin -1 NA)f C /f F <L Y Wherein f is a positive power of the Fourier lens, and an imaging lens O Is the equivalent focal length of the high power objective lens, NA is the numerical aperture of the high power objective lens, f C Is the focal length of the imaging lens, f F Is the focal length of the Fourier lens, L X Horizontal dimension of CCD camera, L Y The vertical size of the CCD camera enables the maximum diameter of a focal plane image behind the objective lens to be limited within a CCD receiving range; real image magnification (f) C ·f F )/(f I ·f O ) The projection area of the sample to be detected on the CCD is smaller than the area of the CCD after the sample to be detected is amplified;
step 2, installing and calibrating the test system
When the system comprises a Kohler lens, an iris diaphragm and a secondary focusing lens, the following processes are included:
the method comprises the steps that a test system is set up, an optical fiber is connected with a light source, a light source focusing lens and a beam splitter are sequentially arranged on a light path led in by the optical fiber from near to far, a high-magnification objective lens and a six-axis objective table are arranged on a reflection light path of the beam splitter, a Fourier lens, a secondary focusing lens, an imaging lens, a variable neutral density filter and a CCD camera are sequentially arranged on a transmission light path of the beam splitter from near to far, and the CCD camera is connected with a computer; loading a silver reflector on a six-axis objective table, wherein the light path direction is in the order of an optical fiber, a light source focusing lens, a beam splitter, a high-magnification objective lens, the silver reflector, the high-magnification objective lens, the beam splitter, a Fourier lens, a secondary focusing lens, an imaging lens, a variable neutral density optical filter and a CCD camera; adjusting the distance between the objective and the objective to make the computer present an image as a reflector surface focusing image; removing the secondary focusing lens; adjusting the variable neutral density filter to enable the maximum value of the image brightness obtained by the computer to be close to saturation; recording the image and measuring the image brightness 1/e 2 The width in the horizontal direction and the width in the vertical direction are respectively X 1 Pixel and Y 1 A pixel;
when the system does not comprise a Kohler lens, an iris diaphragm and a secondary focusing lens, the following processes are included:
building a test system, wherein a Fourier lens is not arranged at the moment; connecting an optical fiber with a light source, sequentially arranging a light source focusing lens and a beam splitter on a light path led by the optical fiber from near to far, arranging a high-magnification objective lens and a six-axis objective table on a reflection light path of the beam splitter, sequentially arranging an imaging lens, a variable neutral density filter and a CCD camera on a transmission light path of the beam splitter from near to far, and connecting the CCD camera with a computer; loading a silver reflector on a six-axis objective table, wherein the light path direction is in the order of an optical fiber, a light source focusing lens, a beam splitter, a high-magnification objective lens, the silver reflector, the high-magnification objective lens, the beam splitter, an imaging lens, a variable neutral density optical filter and a CCD camera; adjusting the distance between the objective and the objective to make the computer present an image as a reflector surface focusing image; adding a Fourier lens between the beam splitter and the imaging lens; adjusting the variable neutral density filter to enable the maximum value of the image brightness obtained by the computer to be close to saturation; recording the image and measuring the image brightness 1/e 2 The width in the horizontal direction and the width in the vertical direction are respectively X 1 Pixel and Y 1 A pixel;
step 3, testing the sample
When the system comprises a Kohler lens, an iris diaphragm and a secondary focusing lens, the following processes are included:
loading a sample to be tested on a sample table, building a test system, connecting an optical fiber with a light source, sequentially arranging a light source focusing lens, a Kohler lens and a beam splitter on a light path led by the optical fiber from near to far, arranging a high-magnification objective lens and a six-axis objective table on a reflection light path of the beam splitter, sequentially arranging a Fourier lens, a secondary focusing lens, an imaging lens, a variable neutral density filter and a CCD camera on a transmission light path of the beam splitter from near to far, arranging an iris diaphragm between the Fourier lens and the secondary focusing lens, enabling the light path to pass through a hole on the iris diaphragm, and connecting the CCD camera with a computer; the optical path direction is determined according to the optical fiber, the light source focusing lens, the Kohler lens, the beam splitter, the high-magnification objective lens, the sample to be measured, the high-magnification objective lens, the beam splitter,Fourier lens, variable diaphragm, secondary focusing lens, imaging lens, variable neutral density filter, CCD camera; adjusting the distance between the objective lens and the objective table to enable the computer to present an image as a sample surface reflection real image; positioning the position near the light emergent part of the sample by a reflected real image; enabling a sample to be self-luminous, removing a beam splitter in an optical path, and changing the direction of the optical path into the sample to be detected, a high-magnification objective lens, a Fourier lens, an iris diaphragm, a secondary focusing lens, an imaging lens, a variable neutral density optical filter and a CCD camera; further moving the sample to center and focus the light spot seen by the CCD camera; changing the size of the iris diaphragm to limit the imaging range to be only near the facula; removing the secondary focusing lens, and adjusting the variable neutral density filter to ensure that the maximum brightness value of the image obtained by the computer is the same as that of the calibration image; recording the image and measuring the image brightness 1/e 2 The width in the horizontal direction and the width in the vertical direction are respectively X 2 Pixel and Y 2 A pixel;
when the system does not comprise a Kohler lens, an iris diaphragm and a secondary focusing lens, the following processes are included:
loading a sample to be detected on a sample table, wherein no Fourier lens is arranged; connecting an optical fiber with a light source, sequentially arranging a light source focusing lens and a beam splitter on a light path led by the optical fiber from near to far, arranging a high-magnification objective lens and a six-axis objective table on a reflection light path of the beam splitter, sequentially arranging an imaging lens, a variable neutral density filter and a CCD camera on a transmission light path of the beam splitter from near to far, and connecting the CCD camera with a computer; the light path direction is according to the order of the optical fiber, the light source focusing lens, the beam splitter, the high-magnification objective lens, the sample to be detected, the high-magnification objective lens, the beam splitter, the imaging lens, the variable neutral density optical filter and the CCD camera; adjusting the distance between the objective lens and the objective table to enable the computer to present an image as a sample surface reflection real image; positioning the vicinity of the light emergent part of the sample through a reflected real image; enabling the sample to be self-luminous, removing a beam splitter in an optical path, and changing the direction of the optical path into the sample to be detected, a high-magnification objective lens, an imaging lens, a variable neutral density optical filter and a CCD camera; further moving the sample to center and focus the light spot seen by the CCD camera; adding Fourier lens to beam splitter and imaging lensBetween the mirrors; adjusting the variable neutral density filter to ensure that the maximum value of the image brightness obtained by the computer is the same as the calibration image; recording the image and measuring the image brightness 1/e 2 The width in the horizontal direction and the width in the vertical direction are respectively X 2 Pixel and Y 2 A pixel;
step 4, data processing
By comparing the calibration data with the reference measurement data, the horizontal divergence angle of the sample is calculated as
Figure FDA0003867090280000021
Corresponding to Gaussian spot having horizontal diameter of
Figure FDA0003867090280000022
A vertical divergence angle of
Figure FDA0003867090280000023
Corresponding to a Gaussian spot having a vertical diameter of
Figure FDA0003867090280000024
2. The high-precision light spot testing method based on the space imaging system according to claim 1, further comprising the following steps: and measuring the size of the far-field image of the sample to be measured according to the intensity distribution diagram of the Fourier image of the sample.
3. The high-precision light spot testing system based on the space imaging system is characterized by comprising a wide-spectrum light source, an optical fiber, a light source focusing lens, a beam splitter, a high-magnification objective lens, a six-axis objective table, a Fourier lens, an imaging lens, a variable neutral density optical filter, a CCD camera and a computer;
the wide-spectrum light source is connected with an optical fiber, the light source focusing lens and the beam splitter are sequentially arranged on a light path led by the optical fiber from near to far, the high-magnification objective lens and the six-axis objective table are arranged on a reflection light path of the beam splitter, the Fourier lens, the imaging lens, the variable neutral density optical filter and the CCD camera are sequentially arranged on a transmission light path of the beam splitter from near to far, and the CCD camera is connected with a computer;
the optical fiber introduces light of a wide-spectrum light source into the system; the light source focusing lens is used for collimating light emitted by the wide-spectrum light source through the optical fiber; the beam splitter is used for combining the reflection light path and the transmission light path into one path in front of the objective lens; the high-magnification objective lens is used for collecting light in all emission directions of a sample to be detected; the six-axis objective table is used for loading a sample to be tested; the Fourier lens is used for focusing a rear focal plane image behind the objective lens and performing optical Fourier transform on the near-field light spot to obtain a far-field image corresponding to the near-field light spot; the imaging lens is used for enabling a CCD camera to form a focusing real image; the variable neutral density filter is used for reducing the light transmission quantity; and the computer is used for receiving and processing the CCD camera image.
4. The high-precision light spot testing system based on the space imaging system is characterized by further comprising a Kohler lens, an iris diaphragm and a secondary focusing lens;
the Kohler lens is arranged between the light source focusing lens and the beam splitter, the iris diaphragm and the secondary focusing lens are arranged between the Fourier lens and the imaging lens and are positioned on a transmission light path of the beam splitter, the iris diaphragm is positioned at the position where the back focal point of the Fourier lens is overlapped with the front focal point of the secondary focusing lens, and the transmission light path penetrates through a hole in the iris diaphragm;
the Kohler lens is used for forming a Kohler illumination system in front of the objective lens to enlarge the illumination range of the objective lens; the variable diaphragm is used for filtering stray light; the secondary focusing lens is used for focusing the rear focal plane image of the Fourier lens, and real-imaging the wave front at the position of the iris diaphragm, so that the filtering range is convenient to adjust.
5. The high-precision light spot testing system based on the space imaging system as claimed in claim 3 or 4, wherein the light source focusing lens, the Kohler lens, the Fourier lens, the secondary focusing lens and the imaging lens are all aspheric lenses, and the lenses are aspheric lensesPlating antireflection films with corresponding wavelengths on two sides, wherein the diameter of the lens is not less than 1 inch; the parameters of the high-power objective lens, the Fourier lens and the imaging lens should satisfy 2f O tan(sin -1 NA)f C /f F <L X ,2f O tan(sin -1 NA)f C /f F <L Y Where Lx and Ly are the transverse and longitudinal dimensions of the CCD, respectively.
6. The high-precision light spot testing system based on the space imaging system as claimed in claim 3 or 4, wherein the parameter to be tested of the sample to be tested is a divergence angle θ<sin -1 NA。
7. The high-precision light spot testing system based on the spatial imaging system according to claim 3 or 4, wherein the beam splitter is a film beam splitter or a bulk beam splitter, the two sides of the beam splitter are coated with antireflection films with corresponding wavelengths, and the splitting ratio is 50.
8. The high-precision light spot testing system based on the space imaging system as claimed in claim 3 or 4, wherein the high-power objective lens has a magnification M not less than 40 times, a numerical aperture NA not less than 0.5 and less than 1, and is coated with an anti-reflection film with a corresponding wavelength.
9. The spatial imaging system-based high-precision light spot testing system according to claim 4, wherein the variable range of the iris diaphragm aperture is 0.1 mm to 10 mm.
10. The high-precision light spot testing system based on the space imaging system according to claim 3 or 4, wherein the wide-spectrum light source is a halogen lamp, and the wavelength covers visible light to near infrared; the optical fiber is typically a multimode optical fiber having a diameter of less than 1 mm; the variable neutral density filter has a neutral density variable range of 0.1 to 4.
CN202211181737.9A 2022-09-27 2022-09-27 High-precision light spot testing system and method based on space imaging system Pending CN115628686A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
CN202211181737.9A CN115628686A (en) 2022-09-27 2022-09-27 High-precision light spot testing system and method based on space imaging system
PCT/CN2022/126157 WO2024065898A1 (en) 2022-09-27 2022-10-19 High-precision light spot test system and method based on space imaging system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202211181737.9A CN115628686A (en) 2022-09-27 2022-09-27 High-precision light spot testing system and method based on space imaging system

Publications (1)

Publication Number Publication Date
CN115628686A true CN115628686A (en) 2023-01-20

Family

ID=84904772

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202211181737.9A Pending CN115628686A (en) 2022-09-27 2022-09-27 High-precision light spot testing system and method based on space imaging system

Country Status (2)

Country Link
CN (1) CN115628686A (en)
WO (1) WO2024065898A1 (en)

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5889593A (en) * 1997-02-26 1999-03-30 Kla Instruments Corporation Optical system and method for angle-dependent reflection or transmission measurement
EP1657580A1 (en) * 2004-11-11 2006-05-17 Eldim Sa Optical device for determining the in-focus position of a fourier optics set-up
CN104634699B (en) * 2015-02-28 2017-05-10 河南科技大学 Laguerre-gaussian beam-based speckle contrast imaging measurement device and laguerre-gaussian beam-based speckle contrast imaging measurement method
CN105953739B (en) * 2016-06-29 2020-07-14 武汉纺织大学 Transverse deformation measurement system and method based on laser irradiation intensity change
CN107702793A (en) * 2017-10-31 2018-02-16 深圳前海百炼光特种照明有限公司 A kind of test system and method for testing of hot spot light distribution
CN114778078A (en) * 2022-03-18 2022-07-22 中国科学院上海光学精密机械研究所 Automatic addressing method and device for spatial intensity peak of Gaussian spot

Also Published As

Publication number Publication date
WO2024065898A1 (en) 2024-04-04

Similar Documents

Publication Publication Date Title
JP6629369B2 (en) System and method for improving focus tracking using a hybrid mode light source
CA2997777C (en) Systems and methods for improved focus tracking using a light source configuration
JP5172204B2 (en) Optical characteristic measuring apparatus and focus adjustment method
CN107796330B (en) A kind of white light interference measuring three-dimensional morphology optical system
CA3061237C (en) Systems and methods for improved focus tracking using blocking structures
TW201407128A (en) Chromatic confocal scanning apparatus
CN113137931B (en) Spectrum confocal device and method capable of measuring surface shape or thickness
CN112556991A (en) Lens refractive index measuring device and measuring method thereof
CN210863101U (en) Lens refractive index measuring device
CN110986836B (en) High-precision roughness measuring device based on annular core optical fiber
CN115628686A (en) High-precision light spot testing system and method based on space imaging system
CN116773147A (en) Laser output light spot characteristic measuring device and method
CN115307748A (en) Device and method for measuring far and near field light spot modes of laser communication load
CN113295386B (en) Optical lens piece detection system and detection method
US11333487B2 (en) Common path mode fiber tip diffraction interferometer for wavefront measurement
CN114441531A (en) Automatic focusing method with image recognition, device, computer and storage medium
JP2012013686A (en) Interferometer
CN114486198B (en) Large-caliber reflector detection system
CN220872351U (en) Optical detection device and film testing equipment
KR20190003363A (en) Line width measuring system and line width measuring device
TWI708040B (en) External reflection-type three dimensional surface profilometer
CN116931236B (en) Double-rate optical system based on probe alignment wafer
CN218584684U (en) Detection system
CN219390835U (en) Detection device
CN219757692U (en) Multi-optical axis consistency detection device

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination