A vortex spectrum dark field microscopic measuring device and method based on vortex quantum correlation

Abstract

The application discloses a vortex spectrum dark field microscopic measurement device and method based on vortex quantum correlation, which comprises an entangled light source generation module, a sample illumination detection module and a vortex spectrum extraction module; the entangled light source generation module sequentially comprises a laser, a half-wave plate, a BBO crystal, a low-pass filter and a non-polarization beam splitter one in the light propagation direction; the sample illumination detection module sequentially comprises a single-mode optical fiber one, a tube lens one, an objective lens one, a sample to be measured, an objective lens two, a tube lens two, a lens one, a lens two, a single-mode optical fiber two and a SPAD detector one in the light propagation direction; and the vortex spectrum extraction module sequentially comprises a mirror one, a mirror two, a liquid crystal spatial light modulator one, a lens three, a lens four, a single-mode optical fiber three and a SPAD detector two in the light propagation direction.

Description

Technical Field

[0001] This invention relates to the field of optical precision measurement technology, and more specifically to a vortex spectrum dark-field microscopy measurement device and method based on vortex quantum correlation. Background Technology

[0002] Currently, high-performance optical components and materials have wide applications in precision instrument manufacturing and major optical engineering research, forming the foundation of optical system performance. Therefore, they play a crucial role in the high-resolution precision detection of mechanical structures, chemical compositions, and lattice structure defects in optical components and materials at the surface and subsurface levels. Phase defects in optical components can cause the incident beam to form a locally focused optical field, leading to localized overheating and irreversible damage. Dark-field confocal microscopy, with its advantages of excellent optical tomography capabilities, high imaging resolution, and high imaging contrast due to the dark background, has become an important means of non-destructive three-dimensional inspection of optical components.

[0003] However, conventional optical dark-field confocal microscopy can only detect geometric defects in samples, such as scratches and bubbles, but its response rate to phase defects is low, and it cannot accurately obtain other physicochemical properties of phase defects in optical components.

[0004] Therefore, how to more comprehensively characterize the defect characteristics of optical components and materials, and more accurately identify and classify phase defects and amplitude defects, is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention provides a vortex spectrum dark-field microscopy measurement device and method based on vortex quantum correlation; while using dark-field confocal illumination under first-order vortex light to obtain structural information of microstructured samples and surface scratches, wear and other defects of industrial optical samples, the present invention also uses vortex scattering dichroism spectroscopy analysis to obtain chiral information of micro and nanostructures, providing a new approach for the detection of micro and nanostructures.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A vortex spectrum dark-field microscopy measurement device based on vortex quantum correlation includes: an entangled light source generation module, a sample illumination detection module, and a vortex spectrum extraction module;

[0008] The entangled light source generation module, in order of light propagation direction, consists of: laser, half-wave plate, BBO crystal, low-pass filter, and non-polarizing beam splitter.

[0009] The sample illumination detection module, arranged in order of light propagation direction, consists of: single-mode fiber 1, tube lens 1, objective lens 1, sample to be tested, objective lens 2, tube lens 2, lens 1, lens 2, single-mode fiber 2, and SPAD detector 1.

[0010] The vortex spectrum extraction module, arranged in order of light propagation direction, consists of: mirror one, mirror two, liquid crystal spatial light modulator one, lens three, lens four, single-mode fiber three, and SPAD detector two.

[0011] Preferably, the laser emits a polarized laser beam, which is generated by the half-wave plate and the BBO crystal to produce an entangled light source with doubled wavelength. The high-frequency components are filtered out by the low-pass filter, and the beam is split into two beams by the non-polarized beam splitter for sample detection and vortex spectrum extraction, respectively.

[0012] Preferably, one beam split from the non-polarizing beam splitter is incident on the single-mode fiber 3, and after passing through the tube lens 1 and the objective lens 1, it is focused onto the sample to be tested.

[0013] Preferably, after the entangled light passes through the sample to be tested, it is collected and amplified by the second objective lens and the second tube lens. After passing through the 4f system formed by the first lens and the second lens, it is incident on the second single-mode fiber and transmitted to the first SPAD detector for detection.

[0014] Preferably, the other entangled light split from the non-polarizing beam splitter passes through the first and second reflectors and is obliquely incident on the first liquid crystal spatial light modulator. A fixed low-order m-order fork grating phase (m = 0, 1, 2) is loaded on the first liquid crystal spatial light modulator, and the output beam is a corresponding m-order vortex beam.

[0015] Preferably, after the output beam of the liquid crystal spatial light modulator passes through the 4f system composed of the lens three and the lens four, it is incident into the single-mode fiber three and transmitted to the SPAD detector two for collection and detection.

[0016] Preferably, the SPAD detector one and the SPAD detector two perform coherent reconstruction to achieve long-distance phase imaging and vortex spectrum extraction of the phase object.

[0017] A dark-field microscopy method based on vortex quantum correlation, comprising the following steps:

[0018] Step 1: The laser emits a polarized laser beam, which generates an entangled light source with doubled wavelength by the half-wave plate and the BBO crystal. The high-frequency components are filtered out by the low-pass filter, and the beam is split into two beams by the non-polarized beam splitter for sample detection and vortex spectrum extraction, respectively.

[0019] Step 2: One beam split from the non-polarization beam splitter is incident on the single-mode fiber 3, and after passing through the tube lens 1 and the objective lens 1, it is focused onto the sample to be tested to collect the sample information.

[0020] Step 3: After the entangled light passes through the sample to be tested, it is collected and amplified by the second objective lens and the second tube lens. After passing through the 4f system composed of the first lens and the second lens, the light information is subjected to spectrum analysis and frequency domain processing.

[0021] Step 4: After passing through the 4f system formed by lens one and lens two, the entangled light is incident on the single-mode fiber two and transmitted to the SPAD detector one for detection.

[0022] Step 5: The other entangled light split from the non-polarizing beam splitter passes through the first reflector and the second reflector and then enters the liquid crystal spatial light modulator.

[0023] Step 6: Adjust the angle of the second reflector so that the entangled light is obliquely incident on the first liquid crystal spatial light modulator;

[0024] Step 7: Load a fixed m-order fork grating phase, where m = 0, 1, 2, onto the liquid crystal spatial light modulator, and the output beam is a corresponding m-order vortex beam.

[0025] Step 8: After the emitted m-order vortex beam passes through the 4f system composed of lens three and lens four, the optical information is subjected to spectrum analysis and frequency domain processing.

[0026] Step 9: After passing through the 4f system formed by lens one and lens two, the entangled light is incident on the single-mode fiber two and transmitted to the SPAD detector one for detection.

[0027] Step 10: The SPAD detector one and the SPAD detector two perform coherent reconstruction to achieve long-range phase imaging and vortex spectrum extraction of the phase object.

[0028] Step 11: Change the value of n from 0 to 10 sequentially, and repeat steps 1-11 to obtain the vortex spectrum of the sample.

[0029] As can be seen from the above technical solution, compared with the prior art, the present invention discloses a vortex spectrum dark-field microscopy measurement device and method based on vortex quantum correlation; while using dark-field confocal illumination under first-order vortex light to obtain structural information of microstructure samples and surface scratches, wear and other defect information of industrial optical samples, it uses vortex scattering dichroism spectroscopy analysis to obtain chiral information of micro and nanostructures, providing a new approach for the detection of micro and nanostructures. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0031] Figure 1 The attached figure is a schematic diagram of the vortex spectrum dark field microscopy measurement device based on vortex quantum correlation provided by the present invention.

[0032] Among them, 1 is a laser, 2 is a half-wave plate, 3 is a BBO crystal, 4 is a low-pass filter, 5 is a non-polarizing beam splitter, 6 is a single-mode fiber 1, 7 is a tube lens 1, 8 is an objective lens 1, 9 is the sample to be tested, 10 is an objective lens 2, 11 is a tube lens 2, 12 is a lens 1, 13 is a lens 2, 14 is a single-mode fiber 2, 15 is a SPAD detector 1, 16 is a reflector 1, 17 is a reflector 2, 18 is a liquid crystal spatial light modulator, 19 is a lens 3, 20 is a lens 2, 21 is a single-mode fiber, and 22 is a SPAD detector. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] This invention discloses a vortex spectrum dark-field microscopy measurement device based on vortex quantum correlation, comprising: an entangled light source generation module, a sample illumination detection module, and a vortex spectrum extraction module;

[0035] The entangled light source generation module, arranged in the order of light propagation direction, consists of: laser 1, half-wave plate 2, BBO crystal 3, low-pass filter 4, and non-polarizing beam splitter 5.

[0036] The sample illumination detection module, arranged in order of light propagation direction, consists of: single-mode fiber 16, tube lens 17, objective lens 18, sample to be tested 9, objective lens 2 10, tube lens 2 11, lens 12, lens 2 13, single-mode fiber 2 14, and SPAD detector 15.

[0037] The vortex spectrum extraction module, arranged in order of light propagation direction, consists of: mirror 16, mirror 2, liquid crystal spatial light modulator 18, lens 3 19, lens 4 20, single-mode fiber 3 21, and SPAD detector 2 22.

[0038] To further optimize the above technical solution, laser-1 emits X-polarized laser light, which is then generated by half-wave plate-2 and BBO crystal-3 to produce an entangled light source with doubled wavelength. The high-frequency components are filtered out by low-pass filter-4, and the light is split into two beams by non-polarized beam splitter-5 for sample detection and vortex spectrum extraction, respectively.

[0039] To further optimize the above technical solution, one beam split from the non-polarization beam splitter 5 is incident on the single-mode fiber 21, and after passing through the tube lens 7 and the objective lens 8, it is focused onto the sample 9 to be tested.

[0040] To further optimize the above technical solution, after the entangled light passes through the sample 9 to be tested, it is collected and amplified by objective lens 2 10 and tube lens 2 11. After passing through the 4f system composed of lens 1 12 and lens 2 13, it is incident on single-mode fiber 2 14 and transmitted to SPAD detector 1 15 for detection.

[0041] To further optimize the above technical solution, the other entangled light split from the non-polarization beam splitter 5 passes through mirror 16 and mirror 17 and is obliquely incident on the liquid crystal spatial light modulator 18. A fixed m-order fork grating with phase m = 0, 1, 2 is loaded on the liquid crystal spatial light modulator 18, and the output beam is a corresponding m-order vortex beam.

[0042] To further optimize the above technical solution, the output beam of the liquid crystal spatial light modulator 18 is incident into the single-mode fiber 21 after passing through the 4f system composed of lens 3 19 and lens 4 20, and is transmitted to the SPAD detector 2 22 for collection and detection.

[0043] To further optimize the above technical solution, SPAD detector 15 and SPAD detector 22 are coherently reconstructed to achieve long-distance phase imaging and vortex spectrum extraction of phase objects.

[0044] A dark-field microscopy method based on vortex quantum correlation, comprising the following steps:

[0045] Step 1: Laser-1 emits X-polarized laser light, which is then generated by half-wave plate-2 and BBO crystal 3 to produce an entangled light source with doubled wavelength. The high-frequency components are filtered out by low-pass filter 4, and the light is split into two beams by non-polarized beam splitter-5 for sample detection and vortex spectrum extraction, respectively.

[0046] Step 2: One beam of light split from the non-polarizing beam splitter 5 is incident on the single-mode fiber 21, and after passing through the tube lens 7 and the objective lens 8, it is focused onto the sample to be tested 9 to collect the sample information.

[0047] Step 3: After the entangled light passes through the sample 9, it is collected and amplified by objective lens 2 10 and tube lens 2 11. After passing through the 4f system composed of lens 1 12 and lens 2 13, the light information is subjected to spectrum analysis and frequency domain processing.

[0048] Step 4: After passing through the 4f system composed of lens 12 and lens 13, the entangled light is incident on single-mode fiber 14 and transmitted to SPAD detector 15 for detection.

[0049] Step 5: The other entangled light split from the non-polarization beam splitter 5 passes through mirror 16 and mirror 17 and then enters the liquid crystal spatial light modulator 18.

[0050] Step 6: Adjust the angle of the second reflector 17 so that the entangled light is obliquely incident on the liquid crystal spatial light modulator 18;

[0051] Step 7: Load a fixed m-order fork grating phase, where m = 0, 1, 2, onto the liquid crystal spatial light modulator-18, and the output beam is a corresponding m-order vortex beam.

[0052] Step 8: After the emitted m-order vortex beam passes through the 4f system consisting of lens 19 and lens 20, the optical information is subjected to spectrum analysis and frequency domain processing.

[0053] Step 9: After passing through the 4f system composed of lens 12 and lens 13, the entangled light is incident on single-mode fiber 14 and transmitted to SPAD detector 15 for detection.

[0054] Step 10: SPAD detector 15 and SPAD detector 22 perform coherent reconstruction to achieve long-range phase imaging and vortex spectrum extraction of the phase object.

[0055] Step 11: Change the value of n from 0 to 10 sequentially, and repeat steps 1-11 to obtain the vortex spectrum of the sample.

[0056] Beneficial effects:

[0057] Based on the extracted first-order spectral components of the vortex spectrum, ordinary dark-field measurements of the sample can be achieved; based on the analysis of the extracted higher-order spectral components of the vortex spectrum, phase information of a sample with a fixed structure can be obtained, and amplitude information of a sample with a fixed phase distribution can also be acquired.

[0058] The device uses Gaussian illumination, which avoids the requirement of traditional dark-field confocal measurements that the objective aperture is larger than the inner diameter of the ring light, and is beneficial for using large numerical aperture objectives for high-resolution dark-field imaging.

[0059] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0060] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A vortex spectrum dark field microscopic measuring device based on vortex quantum correlation, characterized in that, include: Entangled light source generation module, sample illumination detection module, and vortex spectrum extraction module; The entangled light source generation module is arranged in the following order according to the direction of light propagation: laser (1), half-wave plate (2), BBO crystal (3), low-pass filter (4), and non-polarizing beam splitter (5). The sample illumination detection module is arranged in the following order according to the direction of light propagation: single-mode fiber 1 (6), tube lens 1 (7), objective lens 1 (8), sample to be tested (9), objective lens 2 (10), tube lens 2 (11), lens 1 (12), lens 2 (13), single-mode fiber 2 (14), and SPAD detector 1 (15). The vortex spectrum extraction module is arranged in the following order according to the direction of light propagation: mirror one (16), mirror two (17), liquid crystal spatial light modulator one (18), lens three (19), lens four (20), single-mode fiber three (21) and SPAD detector two (22). The beam split by the non-polarization beam splitter (5) is incident on the single-mode fiber (21), and after passing through the tube lens (7) and the objective lens (8), it is focused onto the sample to be tested (9). The other entangled light split by the non-polarizing beam splitter (5) passes through the first reflector (16) and the second reflector (17) and is obliquely incident on the first liquid crystal spatial light modulator (18). A fixed m-order fork grating phase with m=0, 1, 2 is loaded on the first liquid crystal spatial light modulator (18), and the output beam is a vortex beam of order m.

2. The vortex spectrum dark field microscopic measurement device based on vortex quantum correlation according to claim 1, characterized in that, The laser-1 (1) emits a polarized laser beam, which is generated by the half-wave plate (2) and the BBO crystal (3) to produce an entangled light source with doubled wavelength. The high-frequency components are filtered out by the low-pass filter (4), and the beam is split into two beams by the non-polarized beam splitter (5) for sample detection and vortex spectrum extraction, respectively. 3.The vortex spectrum dark field microscopic measurement device based on vortex quantum correlation according to claim 1, wherein, After passing through the sample to be tested (9), the entangled light is collected and amplified by the second objective lens (10) and the second tube lens (11). After passing through the 4f system composed of the first lens (12) and the second lens (13), it is incident on the second single-mode fiber (14) and transmitted to the first SPAD detector (15) for detection.

4. The vortex spectrum dark field microscopic measurement device based on vortex quantum correlation according to claim 1, characterized in that, After the output beam of the liquid crystal spatial light modulator (18) passes through the 4f system composed of the lens (19) and the lens (20), it is incident into the single-mode fiber (21) and transmitted to the SPAD detector (22) for collection and detection.

5. The vortex spectrum dark field microscopic measurement device based on vortex quantum correlation according to claim 1, characterized in that, The SPAD detector one (15) and the SPAD detector two (22) perform coherent reconstruction to achieve long-distance phase imaging and vortex spectrum extraction of phase objects.

6. A vortex spectrum dark field microscopic measurement method based on vortex quantum correlation, the method is realized based on the vortex spectrum dark field microscopic measurement device based on vortex quantum correlation in any one of claims 1-5, characterized in that: Specific steps: Step 1: The laser-1 (1) emits X-ray polarized laser light, which is generated by the half-wave plate (2) and the BBO crystal (3) to double the wavelength of the entangled light source. The high-frequency components are filtered out by the low-pass filter (4), and the light is split into two beams by the non-polarized beam splitter (5) for sample detection and vortex spectrum extraction, respectively. Step 2, one of the light beams split by the non-polarization beam splitter one (5) is incident into the single-mode optical fiber three (21), and after passing through the tube lens one (7) and the objective lens one (8), it is focused on the sample to be measured (9) to collect the information of the sample to be measured; Step 3, after the entangled light passes through the sample to be measured (9), it is collected and amplified by the objective lens two (10) and the tube lens two (11), and after passing through the 4f system composed of the lens one (12) and the lens two (13), the light information is subjected to spectral analysis and frequency domain processing; Step 4, after the entangled light passes through the 4f system composed of the lens one (12) and the lens two (13), it is incident into the single-mode optical fiber two (14) and transmitted to the SPAD detector one (15) for detection; Step 5, the other entangled light beam split by the non-polarization beam splitter one (5) passes through the mirror one (16) and the mirror two (17) and is incident on the liquid crystal spatial light modulator one (18); Step 6, the angle of the mirror two (17) is adjusted so that the entangled light is obliquely incident on the liquid crystal spatial light modulator one (18); Step 7, a fixed m-order lower-order m-order forked grating phase is loaded on the liquid crystal spatial light modulator one (18), where m=0, 1, 2, and the outgoing light beam is an m-order vortex light beam; Step 8, after the m-order vortex light beam is incident on the 4f system composed of the lens three (19) and the lens four (20), the light information is subjected to spectral analysis and frequency domain processing; Step 9, after the entangled light passes through the 4f system composed of the lens one (12) and the lens two (13), it is incident into the single-mode optical fiber two (14) and transmitted to the SPAD detector one (15) for detection; Step 10, the SPAD detector one (15) and the SPAD detector two (22) are subjected to coherent reconstruction to realize remote phase imaging of the phase object and extraction of the vortex spectrum; Step 11, the value of m is changed from 0 to 2 in sequence, and steps 1-11 are repeated to obtain the vortex spectrum of the sample.

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