Multi-channel parallel structure interference optical system and interference measurement method

Abstract

The invention provides a multi-channel parallel structure interference optical system and an interference measurement method, and the system comprises a multi-channel parallel light source array which comprises a plurality of independently modulated sub-light sources, each sub-light source at least comprises dual-wavelength output, and generates an angle integral illumination light beam which forms an angle theta with a main optical axis through a micro-concave lens or an optical steering device, spatial incoherent illumination is realized; the interference light path module is used for dividing the light beam from the multi-channel parallel light source array into a scene arm and a reference arm and generating an interference light signal; the compound eye sensor array comprises a plurality of monocular sensors, each monocular is in one-to-one correspondence with the sub light sources of the multi-channel parallel light source array, and each monocular of the compound eye sensor array correspondingly receives an interference light signal from one sub light source and outputs an interference pattern; the problems that a traditional single-channel interference system is low in detection efficiency and poor in environmental adaptability are solved, and high-precision, wide-range and anti-interference multi-physical-quantity synchronous measurement is achieved.

Description

Technical Field

[0001] The present invention relates to the field of optoelectronic detection technology, and particularly to a multi-channel parallel structure interference optical system and an interference measurement method. Background Art

[0002] As a high-precision measurement and imaging tool, the interference optical system has been widely used in the fields of precision manufacturing, biomedicine, material detection, etc. Traditional interferometers (such as Michelson interferometers, Mach-Zehnder interferometers) achieve the measurement of optical path difference through beam splitting and beam combining, but their single mode (such as fixed wavelength, fixed optical path) limits their dynamic adaptability and multi-parameter synchronous detection ability in complex scenarios. For example, in the dynamic observation of living cells or the three-dimensional topography measurement of micro-nano structures, it is necessary to simultaneously consider a large field of view, high lateral resolution, and sub-nanometer axial measurement accuracy, while traditional systems are difficult to meet the requirements of multi-modal (such as multi-wavelength, multi-angle, multi-polarization) fusion. Traditional interferometers (such as Zygo NewView 8300) use point-by-point scanning, and it takes several minutes for large-field measurement, while high-speed detection (such as semiconductor wafer defect monitoring) requires sub-millisecond response; single-channel systems cannot capture the instantaneous state of moving targets (such as vibrating MEMS devices), and the phase information is easily contaminated by motion artifacts. Summary of the Invention

[0003] Based on the above problems, the present invention provides a multi-channel parallel structure interference optical system and an interference measurement method, which solve the three core problems of low detection efficiency, poor environmental adaptability, and lack of multi-modal ability existing in traditional single-channel interference systems through multi-channel parallel detection, compound eye sensor redundancy compensation, and integral light source regulation technology, and realize high-precision, wide-range, and anti-interference synchronous measurement of multi-physical quantities.

[0004] In the first aspect, the present application provides a multi-channel parallel structure interference optical system, and the system includes:

[0005] A multi-channel parallel light source array, including a plurality of independently modulated sub-light sources, each sub-light source at least includes dual-wavelength output, and generates an angular integral illumination beam along an angle θ with the main optical axis through a micro concave mirror or an optical steering device to achieve spatially incoherent illumination;

[0006] An interference optical path module, configured to divide the beam from the multi-channel parallel light source array into a scene arm and a reference arm, and generate an interference optical signal;

[0007] A compound eye sensor array, including a plurality of single-eye sensors, each single-eye corresponding to a sub-light source of the multi-channel parallel light source array one by one. After the light emitted by the multi-channel parallel light source array is processed by the interference optical path module, it is incident on the compound eye sensor array, and each single-eye of the compound eye sensor array correspondingly receives the interference optical signal from a sub-light source and outputs an interference pattern.

[0008] Preferably, generating an angular integrated illumination beam at an angle of θ with respect to the principal optical axis through a microlens or an optical steering device includes:

[0009] Performing an angular scan of θ on each sub-light source through a microlens or an optical steering device to form spatially incoherent illumination; the scan angle of each sub-light source is independently controllable; θ ∈ [-Θ / 2, Θ / 2]; Θ is the maximum scan angle, which is jointly determined by the emission area and the lens focal length;

[0010] Aberrations of the integrated beam are reduced through coaxial fiber coupling technology, and speckle noise is eliminated through Gaussian low-pass filtering combined with bilateral filtering.

[0011] Preferably, the interference optical path module is based on a Michelson interferometer architecture, and includes a beam splitter, a scene arm objective lens, a reference arm translation mirror, and an interference generator; the beam is split by the beam splitter, the sample information is collected by the scene arm objective lens, the optical path is adjusted by the reference arm translation mirror, and finally the two beams of light are interfered by the interference generator.

[0012] Preferably, the surface of the single-eye sensor of the compound eye sensor array is located at the conjugate position of the rear focal plane of the scene arm objective lens, receives the interference light of the scene arm and the reference arm, and outputs an original image containing multiple sub-region interference patterns.

[0013] Preferably, the sub-regions of the compound eye sensor array can overlap, and adjacent sub-regions are distinguished by differences in light source amplitude, wavelength, or polarization; each single-eye in the compound eye sensor array receives the corresponding channel signal; the phase is calculated in real time to resolve the depth; the data in the overlapping region is weighted and fused to eliminate the stitching error.

[0014] Optionally, each sub-light source of the multi-channel parallel light source array is an independent light-emitting body;

[0015] Or,

[0016] Multiple sub-light sources are generated from the same initial light source through a beam splitter, a polarizer, and a compensator.

[0017] Preferably, each sub-light source generates a focused beam through a fiber coupler, a circulator, and a collimator, and only illuminates the corresponding conjugate points of the scene arm and the reference arm.

[0018] Preferably, the system further includes an AI integration algorithm processor for processing the signals collected by each receptor to form an overall image and a result report.

[0019] Preferably, the system further includes a dynamic phase compensation module, and the phase compensation module is configured to:

[0020] Extract the phase difference of the interference signals of adjacent channels through the redundant sub-regions of the compound eye sensor array

[0021] Based on phase difference Calculate the phase drift

[0022] according to Compensate for the displacement of the reference arm translation mirror and synchronously adjust the wavelengths λ1 and λ2 of the sub-light sources to keep the synthetic wavelength constant;

[0023] After compensation, the phase consistency of the overlapping area is re-measured. If the residual phase error exceeds the preset threshold, the secondary compensation is triggered, and the phase consistency is further optimized by adjusting the axial position of the objective lens group and / or fine-tuning the inclination angle of the beam splitter.

[0024] In a second aspect, the present application provides an interference measurement method based on a multi-channel parallel structure interference optical system, comprising the following steps:

[0025] A multi-channel parallel light source array is used to generate multiple independently modulated sub-light sources, each of which contains at least dual-wavelength outputs, and each sub-light source is made to generate an angle superposition integral light beam along an angle θ with the main optical axis through a micro-concave mirror or an optical steering device, thereby realizing spatial incoherent illumination;

[0026] The light emitted by the multi-channel parallel light source array is introduced into the interference optical path module based on the Michelson interferometer architecture to form an interference optical signal;

[0027] The light emitted by the multi-channel parallel light source array is processed by the interference optical path module and then emitted to the compound eye sensor array. Each single eye of the compound eye sensor array receives the interference light signal from a sub-light source and outputs an interference pattern. The compound eye sensor array includes a plurality of monocular sensors, and each monocular corresponds one-to-one to a sub-light source of the multi-channel parallel light source array.

[0028] Compared with the prior art, the beneficial effects of the present invention at least include: through the parallel partition detection design of the multi-channel parallel light source array and the compound eye sensor array, the parallel measurement of micro-nano samples is realized. Each sub-light source corresponds to an independent acquisition area of the compound eye single eye, greatly shortening the detection time and solving the problem of low efficiency of traditional single-channel detection; at the same time, the intelligent comprehensive processing of multi-channel data (such as weighted fusion in the overlapping area) eliminates the stitching error, ensures the accuracy during large-area detection, and effectively balances the contradiction between accuracy and efficiency. An angle-integrated illumination beam is generated by using a micro concave mirror or an optical steering device, the spatial non-coherence is simulated by the superposition of multi-angle beams, and combined with the dual-wavelength synthesis technology (such as SWI), a controllable balance is achieved between a large unambiguous depth range and a high axial resolution, enhancing the ability to capture the Z-axis (depth direction) information of the sample. Compared with the traditional interference system, the Z-axis measurement accuracy is significantly improved, meeting the stringent requirements for depth resolution in micro-nano detection. Integrating multi-modal interference technologies such as ToF, OCT, PSI, and SWI, and flexibly switching through time multiplexing or wavelength multiplexing to adapt to different micro-nano detection scenarios; at the same time, the angle-integrated illumination suppresses speckle noise, combined with coaxial fiber coupling to reduce aberration and filtering algorithms to eliminate interference, further improving the signal quality and ensuring the reliability and stability of the detection results, providing comprehensive technical support for the high-precision 3D shape reconstruction of micro-nano samples. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 FIG. is a schematic structural diagram of a multi-channel parallel structure interference optical system according to an embodiment of the present invention;

[0030] Figure 2 FIG. is a schematic optical path diagram according to an embodiment of the present invention;

[0031] Figure 3a FIG. is a schematic diagram of a multi-channel parallel light source array according to an embodiment of the present invention;

[0032] Figure 3b FIG. is a schematic diagram of a single-point source spectroscopic array according to an embodiment of the present invention;

[0033] Figure 4a FIG. is a schematic diagram of an indirect path caused by lens aberration and subsurface scattering according to an embodiment of the present invention;

[0034] Figure 4b FIG. is a schematic diagram of a stray path caused by optical aberration according to an embodiment of the present invention;

[0035] Figure 4c FIG. is a schematic diagram of an optical wave envelope and its composition according to an embodiment of the present invention;

[0036] Figure 5 FIG. is a schematic diagram of a multi-channel parallel structure light source point light source array according to an embodiment of the present invention;

[0037] Figure 6Schematic diagram of one-to-one correspondence between the light source point, sample area, and sensor in the embodiment of the present invention;

[0038] Figure 7 Schematic diagram of the overlapping of the parallel optical paths in the upper area of the sample in the embodiment of the present invention;

[0039] Figure 8 Schematic diagram of the compound eye sensor array structure in the embodiment of the present invention;

[0040] Figure 9 Schematic diagram of the multi-channel parallel structure interference optical system in the embodiment of the present invention;

[0041] Figure 10 Schematic diagram of the interference measurement method based on the multi-channel parallel structure interference optical system in the embodiment of the present invention.

[0042] In the figure, 100, multi-channel parallel array; 110, initial light source; 120, parallel light source; 200, optical modulation; 300, beam splitter; 310, objective lens; 320, reference mirror; 301, sample; 331, first receiving lens; 332, second receiving lens; 333, interference generator; 340, compound eye sensor array; 202, coupler; 203, collimator; 204, MEMS micromirror; 205, relay mirror; 4, AI integration algorithm; 5, control display. Detailed implementation manners

[0043] In view of the deficiencies in the prior art, the applicant of this case has proposed the technical solution of this application through long-term research and a large number of practices. The following will further explain the technical solution, its implementation process, principles, etc. in combination with the drawings in the embodiments of this application and specific implementation cases.

[0044] It should be noted that the embodiments described below by referring to the drawings are exemplary and are only used to explain this application, and cannot be understood as a limitation to this application. The described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, this application covers any alternatives, modifications, equivalent methods, and solutions defined by the claims and made within the spirit, principle, and scope of this application. All other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of this application.

[0045] In the description of this application, terms such as "first", "second", "third" and similar words do not denote any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "a" or "one" do not denote a quantity limitation, but rather indicate the presence of at least one. Words such as "comprising" or "including" mean that the elements or objects appearing before "comprising" or "including" cover the elements or objects listed after "comprising" or "including" and their equivalents, and do not exclude other elements or objects. Words such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

[0046] In the description of this application, the orientation or positional relationship indicated by terms such as "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. In addition, when using position terms such as both sides, outer side, upper and lower, etc., it should be understood that they are only used for easy understanding and description, considering that the structure may be facing other positions.

[0047] In the description of this application, unless otherwise clearly specified and defined, the technical terms or scientific terms used should have the ordinary meaning understood by those with ordinary skills in the field to which this application belongs. Terms such as "installed", "connected", "coupled", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or a contact connection or an integral connection; for those of ordinary skill in the art, the specific meaning of the above terms in this application can be understood according to specific circumstances.

[0048] Furthermore, in order to enable the public to have a better understanding of this application, in the following detailed description of this application, some specific details are described in detail. Those skilled in the art can fully understand this application without the description of these details.

[0049] Example 1: Referring to Att Figure 1 、Att Figure 2 and Att Figure 9 : This example provides a multi-channel parallel structure interference optical system for micro-nano sample detection. The system includes:

[0050] Multi-channel parallel light source array, including multiple independently modulated sub-light sources, each sub-light source at least includes dual-wavelength output, and generates an angular integral illumination beam along an angle θ with the main optical axis through a micro concave mirror or an optical steering device; multiple sub-light sources of the multi-channel parallel light source array work synchronously, and generate multiple angular integral illumination beams in parallel. Each beam is relatively independent throughout the detection process. Through the multi-beam parallel synchronous detection mechanism, the problems of pixel-level lateral resolution and slow acquisition of depth maps with a precision of one million pixels or more are solved;

[0051] Interference optical path module, used to divide the beam from the multi-channel parallel light source array into a scene arm and a reference arm, and generate an interference optical signal;

[0052] Compound eye sensor array, including multiple single-eye sensors, each single-eye corresponds one-to-one with the sub-light source of the multi-channel parallel light source array. After the light emitted by the multi-channel parallel light source array is processed by the interference optical path module, it is projected onto the compound eye sensor array. Each single-eye of the compound eye sensor array correspondingly receives the interference optical signal from a sub-light source and outputs an interference pattern; each single-eye outputs an independent interference pattern, including depth information and lateral coordinates;

[0053] Among them, the depth information is obtained through the following formula, where l is the optical path of the reference arm (the controllable distance from the reference arm translation mirror (referred to as the reference mirror) to the beam splitter); λ is the wavelength of the light source, d(x) is the distance from the corresponding point of pixel x in the scene to the beam splitter; φ is the interference phase, which directly reflects the distance difference between the scene point and the reference mirror; the depth information is obtained through the real-time interference phase;

[0054] The lateral coordinate is determined by the scanning angle and the focal length of the scene arm objective lens.

[0055] In a possible implementation, dual wavelengths λ1 and λ2 are output by two single-frequency lasers or tunable lasers, and λ2 = λ1 / (1 + ε), where ε ∈ [0.001, 0.1].

[0056] In a possible implementation, the generation of the angular integral illumination beam along an angle θ with the main optical axis through a micro concave mirror or an optical steering device includes:

[0057] Through a micro concave mirror or an optical steering device, each sub-light source is scanned at an angle of θ to form spatially incoherent illumination; the scanning angle of each sub-light source is independently controllable; θ ∈ [-Θ / 2, Θ / 2]; Θ is the maximum scanning angle, which is jointly determined by the emission area and the lens focal length;

[0058] The integral beam reduces aberration through coaxial fiber coupling technology, and eliminates speckle noise through Gaussian low-pass filtering combined with bilateral filtering.

[0059] In a possible implementation, each sub-light source of the multi-channel parallel light source array is an independent light emitter;

[0060] Or,

[0061] Multiple sub-light sources are generated from the same initial light source through a beam splitter, a polarizer, and a compensator;

[0062] As Figure 2 As shown in the optical path schematic diagram of, in a possible implementation, the interference optical path module is based on the Michelson interferometer architecture and includes a beam splitter, a scene arm objective lens, a reference arm translation mirror, and an interference generator; the beam is split by the beam splitter, the sample information is collected by the scene arm objective lens, the optical path is adjusted by the reference arm translation mirror, and finally the two beams of light are interfered by the interference generator.

[0063] In a possible implementation, the surface of the single-eye sensor of the compound eye sensor array is located at the conjugate position of the rear focal plane of the scene arm objective lens, receives the interference light of the scene arm and the reference arm, and outputs an original image containing multiple sub-region interference patterns.

[0064] In a possible implementation, the sub-regions of the compound eye sensor array can overlap, and adjacent sub-regions are distinguished by differences in light source amplitude, wavelength, or polarization; each single eye in the compound eye sensor array receives the corresponding channel signal; the phase is calculated in real time to solve the depth; the data in the overlapping region is weighted and fused to eliminate the stitching error; finally, the depth information and the lateral coordinates of all single eyes are integrated to generate a complete 3D topography map of the micro-nano sample, realizing high-precision micro-nano detection.

[0065] In a possible implementation, each sub-light source of the multi-channel parallel light source array is an independent light emitter;

[0066] Or,

[0067] Multiple sub-light sources are generated from the same initial light source through a beam splitter, a polarizer, and a compensator.

[0068] In a possible implementation, each sub-light source generates a focused beam through a fiber optic coupler, a circulator, and a collimator, and only illuminates the corresponding conjugate points of the scene arm and the reference arm.

[0069] In a possible implementation, the system further includes an AI integration algorithm processor for processing the signals collected by each receptor to form an overall image and a result report.

[0070] The working principle of the above technical solution is as follows: Multiple-channel sub-light sources synchronously emit dual-wavelength light beams, which are dynamically scanned (such as Lissajous trajectories) through a micro concave mirror or an optical steering device (such as a MEMS micromirror) to cover the sample area; After the scene arm light interacts with the sample, it carries height information; The optical path of the reference arm is dynamically adjusted to match the measurement requirements; Each single eye of the compound eye sensor receives the corresponding channel signal; The phase is calculated in real time to solve the depth; The data in the overlapping area is weighted and fused to eliminate the stitching error.

[0071] The sub-light sources support multi-modal switching such as ToF, OCT, PSI, SWI, etc. It can be understood that the multi-channel parallel light source array includes multiple sub-light sources, and each sub-light source consists of an array of light sources that can combine and apply technologies such as coherent time-of-flight (ToF), optical coherence tomography (OCT), phase-shift interferometry (PSI), and synthetic wavelength interferometry (SWI); Multi-modal switching is achieved through independent modulation;

[0072] Figure 2 It is a schematic diagram of the single-channel optical path process, including the light reflected by the sample passing sequentially through the initial light source 110, the parallel light source 120, the optical modulator 200, the beam splitter 300, the objective lens 310, the sample 301, the reference mirror 320, the receiving lens 331, the receiving lens 332, and the interference generator 333, and is incident on the compound eye sensor array 340.

[0073] Figure 2 The parallel light source of can be a parallel fiber optic point light source array, as shown in Figure 3, or it can be the same point light source as the source, such as Figure 3a As shown, the multi-channel parallel light source array contains multiple independently modulated sub-light sources; If the sub-light sources are generated by the same initial light source, its beam splitting structure can refer to Figure 3b The schematic diagram of the single-point source beam splitting array of, and multiple sub-light sources are created through a beam splitter, a polarizer, and a compensator; By placing the beam splitter at different optical paths, a light source with more definite phase correlation and even quantum entanglement characteristics can be obtained, which can expand the uses of this device, such as quantum computing. When this device is used for its main purposes, such as micro-nano structure analysis of semiconductor chips or micro-nano analysis of proteins and cells, the correlation between the parallel light sources can also be incorporated into the subsequent compound eye algorithm to improve accuracy and speed.

[0074] Figure 2 In, the optical modulation generates a single-mode laser beam, which is coupled through the coupler 202, collimated through the collimator 203, passes through the steerable MEMS micro mirror (or micro concave mirror) 204, passes through the relay mirror 205, and reaches the beam splitter 300 to form the overall local optical path.

[0075] In actual micro-nano optical detection, there are often indirect paths caused by lens aberration and subsurface scattering ( Figure 4a ), and stray paths caused by optical aberration ( Figure 4b), resulting in deviations in the optical envelope intensity and phase ( Figure 4c ), affecting the observation or detection effect; the present invention introduces angular integral synthetic light, through a micro concave mirror, or through the Figure 5 steerable MEMS micromirror 204 in it, scans the two-color point source on the focal plane of the illumination lens during exposure to simulate spatial incoherence, constitutes an effective scanning illumination angle, simulates the illumination effect by using illumination composed of two light wavelengths with very small intervals, thereby providing a controllable balance between a large unambiguous depth range and a large axial resolution of PSI, generating an effect between the two extremes of broadband and monochromatic, and realizing angular integral synthetic wavelength interferometry (SWI).

[0076] Two single-frequency lasers or tunable lasers can be used to output two wavelengths λ1 and λ2, λ2 = λ1 / (1 + ε), ε ∈ [0.001, 0.1]; corresponding to wave numbers κ = 2π / λ1 and (1 + ε)κ respectively; the two beams of light are combined through an optical fiber coupler (such as a 2×1 polarization-maintaining fiber coupler) to ensure coaxial transmission, thereby synthesizing a wavelength Λ = λ1λ2 / (λ1 - λ2), achieving a large-range unambiguous measurement (typical Λ value: 10μm - 1mm).

[0077] A fast-tuning laser (such as an SG-DBR laser) can also be used, switch λ1 and λ2 at the μs level through current modulation, and alternately output the two wavelengths through time-division multiplexing (TDM) to avoid channel crosstalk.

[0078] In one implementation, dynamic angular scanning is achieved through a micro concave mirror to destroy spatial coherence. Each sub-light source corresponds to a micro concave mirror, and the micro concave mirror diverges the collimated light beam into a light cone within the θ angle range, where θ is determined by the aperture and focal length of the micro concave mirror;

[0079] In another implementation, an independent MEMS mirror (such as a biaxial resonant mirror) is installed at the end of the optical path of each sub-light source, and dynamic deflection is achieved through electrostatic or electromagnetic drive;

[0080] After the two-wavelength light beams are combined in the optical fiber, they share the same set of micro concave mirrors or MEMS mirrors to ensure that the scanning angles of both are completely synchronized;

[0081] Due to the focal length difference (chromatic aberration) of different wavelengths in the lens, it needs to be corrected by the following methods:

[0082] Use an achromatic objective lens (such as the Nikon CFI Plan Apo λ series);

[0083] Add a diffractive optical element (DOE) in the optical path to compensate for the wavelength-related angular offset.

[0084] The object-image imaging part of the optical setup solution of the present invention is based on the classical Michelson interferometer, such asFigure 2 It consists of an optical modulator 200, a beam splitter 300, a sample stage 301, an objective lens 310, a mirror 320, and an exit lens 331, 332, 333 (optional). The interferometer uses the beam splitter to divide the collimated input illumination into two beams: one beam propagates to the scene arm, and the other beam propagates to the reference arm, which is usually a plane mirror mounted on a translation stage, and the distance from the beam splitter can be varied. After reflection, the two beams of light are recombined at the beam splitter and propagate to the sensor.

[0085] The beam splitter divides the beam of each sub-light source into two paths; one path is projected onto the sample through the objective lens of the scene arm to collect the optical information of the sample; the other path is directed towards the translation mirror of the reference arm to adjust the optical path through the translation mirror;

[0086] The scene arm is focused on the sample surface through the objective lens and carries the sample topography information after reflection;

[0087] The reference arm adjusts the optical path through the translation mirror (displacement accuracy ≤ 10 nm) to form a reference wavefront;

[0088] Michelson architecture: The controllable range of the optical path difference between the two arms is 0 - 100 μm, matching the synthetic wavelength Λ.

[0089] The beams of the scene arm and the reference arm are recombined at the interference generator (such as the beam splitter).

[0090] d(x) is the distance from the corresponding point of pixel x in the scene to the beam splitter; where l is the optical path of the reference arm (the controllable distance from the translation mirror of the reference arm (abbreviation: reference mirror) to the beam splitter), denoted by u r (x, l) and u s (x) respectively represent the complex fields arriving at sensor pixel x from the reference arm and the scene arm; the light intensity I(x, l) received at sensor pixel x is:

[0091]

[0092] |u s (x)| 2 is the light intensity of the complex field u s (x) of the scene arm, representing the light intensity contribution of the scene arm (the optical path carrying the sample information); |u r (x, l)| 2 is the light intensity of the complex field u r (x, l) of the reference arm, reflecting the light intensity contribution of the reference arm (the optical path with controllable optical path); is the complex conjugate of the complex field of the reference arm; Re{} represents taking the real part.

[0093] In the embodiment of the present application, a surface emitter and a point emitter are used to change the illumination from a single collimated beam parallel to the optical axis into a superposition of beams propagating in directions at an angle θ∈[-Θ / 2,Θ / 2] with respect to the optical axis, where Θ depends on the emission area and the lens focal length; using u s t j (θ)(x) and U r t j (θ’)(X,L) represent the complex fields generated by the reflection of each such beam on the scene and the reference arm: the light intensity measured by the sensor is:

[0094] I(X,L)=∫C θ (x,l)dθ

[0095]

[0096] Interference in a non-mirror scene appears in the form of speckles, which is a high-frequency pseudo-random pattern that may cause noise in envelope estimation and phase and depth estimation; illumination at an angle with respect to the optical axis reduces the speckle effect.

[0097] A two-color point source on the focal plane of a scanning or micro concave mirror illumination lens reduces aberration through coaxial illumination using an optical fiber and is received by a corresponding sensor in the compound eye, thereby obtaining an optimized depth detection effect. However, scanning makes it very slow to obtain a depth map with pixel-level lateral resolution and accuracy of one million pixels or more; the present invention further combines multiple-angle integral synthesis wavelength interference in parallel, with multiple beams advancing synchronously and being relatively independent throughout, as Figure 6 shown in the red optical path.

[0098] As Figure 5 shown in the multi-channel parallel structure light source point source array, the spatial layout of the sub-light sources is intuitively presented; each sub-light source generates an angle-integrated illumination beam through a micro concave mirror or an optical steering device, and the optical path direction can be understood in combination with Figure 2 the optical path schematic diagram to clarify the association between angle scanning and the light propagation path; Figure 2 is the optical path schematic diagram, including the light reflected by the sample passing sequentially through the initial light source 110, the parallel light source 120, the optical modulation 200, the beam splitter 300, the objective lens 310, the sample 301, the reference mirror 320, the receiving lens 331, the receiving lens 332, and the interference generator 333, and being incident on the compound eye sensor array 340; Figure 2 The parallel light source 120 can be a parallel optical fiber point source array, as shown in Fig. 3, or a single point light source as the source, as Figure 3a shown, the multi-channel parallel light source array includes multiple independently modulated sub-light sources; if the sub-light sources are generated by the same initial light source, its beam splitting structure can refer to Figure 3b the schematic diagram of the single-point source beam splitting array to create multiple sub-light sources through a beam splitter, a polarizer, and a compensator.

[0099] For each primary light point of the parallel light source array of the present invention, a fiber optic light source (coupler, circulator, collimator) can be used to generate a focused beam. The output of the fiber optic coupled single-frequency laser is placed on the focal plane of the lens to illuminate the corresponding points in the scene and the interference reference arm.

[0100] The compound eye sensor array receives multi-channel interference signals to achieve parallel data acquisition and channel isolation; each single eye sensor forms a conjugate imaging relationship with the corresponding sub-light source; the single eye sensors of the compound eye sensor array correspond one by one with the sub-light sources, and the surface of the single eye is located at the conjugate position of the rear focal plane of the objective lens in the scene arm, accurately receiving the interference light of the scene arm and the reference arm; each single eye outputs an independent interference pattern; as Figure 6 shown, the single eye sensors of the compound eye sensor array, the sub-light sources of the multi-channel parallel light source array, and the sample area form a one-to-one correspondence relationship to ensure the accuracy of signal acquisition; combined with Figure 7 the schematic diagram of the overlapping area of the parallel optical paths on the sample, it can be seen the coverage and overlapping design of the multi-sub-light source optical paths on the sample surface; as Figure 8 the schematic diagram of the compound eye sensor array structure, its array design realizes the parallel acquisition of multi-channel interference signals, each single eye receives the interference light of the corresponding sub-light source, and outputs an independent interference pattern containing depth information and lateral coordinates.

[0101] The reference mirror translation stage uses a translation stage with ultra-high precision, such as nanometer precision, to adjust the position.

[0102] By denoising the estimator with a low-pass filter (such as a Gaussian filter), the influence of speckle can be further reduced. In order to avoid blurring the image details, joint bilateral filtering can also be used, and the scene image under ambient light is used as the guidance image to first blur the envelope estimation to obtain better results. The two-color point source on the focal plane of the scanning illumination lens reduces aberration by using fiber optic coaxial illumination and is received by the parallel one-to-one corresponding sensors in the compound eye, so as to obtain an optimized depth detection effect.

[0103] The signals collected by each sensor are processed by the AI integration algorithm unit, processed by the single-channel processor, integrated by the multi-channel integrator in combination with the pattern and semantic library and the AI deep learning unit to form an overall image and an observation key point sample result report, which is handed over to the control display for display, and the optical components and mechanical components are regulated according to the instructions of the integration algorithm unit.

[0104] The effects of the above technical solutions are as follows: The sub-light source integrates technologies such as ToF, OCT, PSI, and SWI. Through time multiplexing or wavelength multiplexing modes, the detection technology can be flexibly switched according to the scene requirements. For example, ToF realizes fast ranging, OCT completes tomographic imaging, PSI provides high-precision phase measurement, and SWI balances large depth and high resolution to meet the diverse needs of micro-nano detection. The dual-wavelength SWI technology realizes unambiguous depth measurement through the synthetic wavelength (Λ = λ1λ2 / (λ1 - λ2)), and at the same time combines the large axial resolution of PSI to solve the contradiction between the depth range and accuracy in traditional interference technologies.

[0105] Through dynamic angle scanning of the micro concave mirror / MEMS mirror (θ ∈ [-Θ / 2, Θ / 2]), spatial incoherent illumination is simulated to eliminate speckle noise; through the integrated light source, the Z-axis accuracy is improved, and combined with Gaussian low-pass filtering and bilateral filtering, speckle noise is further eliminated, and the errors of envelope estimation and phase-depth calculation are reduced. An achromatic objective lens and a diffractive optical element (DOE) are used to correct the chromatic aberration of the dual wavelength, and combined with the coaxial fiber coupling technology, the optical path aberration is reduced, the beam focusing accuracy is ensured, and the interference signal quality is improved.

[0106] The compound eye sensor array corresponds one-to-one with the multi-channel parallel light source, and each eye receives the interference signal in parallel to achieve fast data acquisition; the sub-region overlapping design combined with the weighted fusion algorithm eliminates the stitching error and improves the efficiency and integrity of 3D topography map reconstruction. The translation mirror of the reference arm adopts a translation stage with nanometer-level accuracy to accurately adjust the optical path (controllable range 0 - 100 μm), match the synthetic wavelength Λ, ensure the accuracy of interference phase calculation, and finally achieve a depth measurement resolution of nanometer level.

[0107] The sub-light source can either emit light independently or be generated from the same initial light source through a beam splitter and a polarizer, adapting to different cost and scene requirements; components such as fiber couplers and circulators realize focused light beams, only illuminating the corresponding conjugate points of the scene arm and the reference arm, reducing the interference of stray light; the independently controllable angle scanning of the micro concave mirror / MEMS mirror adapts to different sample surface characteristics (such as non-mirror speckle scenes), broadens the applicable range of the system, and improves the robustness of complex micro-nano structure detection.

[0108] In a possible implementation, the system further includes a dynamic phase compensation module, and the phase compensation module is configured to:

[0109] Extract the phase difference between the interference signals of adjacent channels through the redundant sub-regions of the compound eye sensor array (for example, the overlapping region ≥ 3%)

[0110] Based on the phase difference Calculate the phase drift amount caused by environmental disturbances where N is the number of overlapping channel pairs;

[0111] according to Drive the translation stage to compensate for the displacement of the reference arm translation mirror. The compensation amount Displacement accuracy ≤λ1 / 100;

[0112] Synchronously adjust the wavelengths λ1 and λ2 of the sub-light sources to keep the synthetic wavelength Λ=λ1λ2 / (λ1-λ2) constant, with a wavelength tuning accuracy of ≤0.01nm;

[0113] After compensation, the phase consistency of the overlapping area is re-measured. If the residual phase error exceeds a preset threshold (e.g., ≥π / 10), the secondary compensation is triggered to further optimize the phase consistency by precisely adjusting the axial position of the objective lens group and / or fine-tuning the inclination angle of the beam splitter;

[0114] Adjust the axial position of the objective lens group (for example: step amount ≤ Λ / 50);

[0115] Fine-tune the beam splitter tilt angle (for example: adjustment range ≤ 0.1°).

[0116] The working principle and effect of the above technical solution are:

[0117] Extracting adjacent channel phase differences through redundant sub-regions Dynamically monitor the phase drift caused by environmental disturbances (such as temperature changes, mechanical vibrations) or thermal expansion of optical components in the optical path

[0118] By synchronously adjusting the dual wavelengths λ1 and λ2 of the sub-light source (keeping the synthetic wavelength λ=λ1λ2 / (λ1-λ2) constant), the influence of phase drift on the interference fringes is offset and the phase consistency of the interference signal is ensured.

[0119] First-level compensation (wavelength adjustment): quickly compensate for small phase drifts through wavelength fine-tuning to avoid delays in mechanical structure adjustment;

[0120] Secondary compensation (objective lens / beam splitter adjustment): When the residual error exceeds the threshold, the larger optical path difference or optical path alignment error is corrected by axially moving the objective lens group or fine-tuning the beam splitter inclination to achieve more accurate phase matching.

[0121] By maintaining the synthetic wavelength constant, the spacing of the interference fringes is ensured to be stable, avoiding measurement errors caused by wavelength fluctuations. By forming a closed-loop feedback through phase re-measurement in the overlapping area, dynamic optimization of the entire process from signal acquisition to compensation execution is achieved to meet the needs of long-term continuous work. The redundant design of the compound eye sensor array is used to achieve phase difference comparison between adjacent channels, solve the synchronization problem when multi-channel parallel light sources are independently modulated, and ensure the spatial consistency of the interference signals of each sub-light source.

[0122] Through dynamic phase compensation, the system can maintain high contrast and phase stability of the interference signal in complex environments, thereby improving imaging resolution, measurement accuracy and anti-interference ability. It is suitable for phase-sensitive application scenarios such as precision detection and biomedical imaging.

[0123] Example 2, refer to the attached Figure 10 This embodiment provides an interference measurement method based on a multi-channel parallel structure interference optical system, comprising the following steps:

[0124] A multi-channel parallel light source array is used to generate multiple independently modulated sub-light sources, each of which contains at least dual-wavelength outputs, and each sub-light source is made to generate an angle superposition integral light beam along an angle θ with the main optical axis through a micro-concave mirror or an optical steering device, thereby realizing spatial incoherent illumination;

[0125] The light emitted by the multi-channel parallel light source array is introduced into the interference optical path module based on the Michelson interferometer architecture to form an interference optical signal;

[0126] The light emitted by the multi-channel parallel light source array is processed by the interference optical path module and then emitted to the compound eye sensor array. Each single eye of the compound eye sensor array receives the interference light signal from a sub-light source and outputs an interference pattern. The compound eye sensor array includes a plurality of monocular sensors, and each monocular corresponds one-to-one to a sub-light source of the multi-channel parallel light source array.

[0127] In a possible implementation, the method further includes:

[0128] Extract the phase difference of the interference signal of adjacent channels through the redundant sub-areas of the compound eye sensor array (e.g. ≥3% overlap area)

[0129] Based on phase difference Calculate the phase drift caused by environmental disturbances Where N is the number of overlapping channel pairs;

[0130] according to Drive the translation stage to compensate for the displacement of the reference arm translation mirror. The compensation amount Displacement accuracy ≤λ1 / 100;

[0131] Synchronously adjust the wavelengths λ1 and λ2 of the sub-light sources to keep the synthetic wavelength Λ=λ1λ2 / (λ1-λ2) constant, with a wavelength tuning accuracy of ≤0.01nm;

[0132] After compensation, the phase consistency of the overlapping area is re-measured. If the residual phase error exceeds a preset threshold (e.g., ≥π / 10), the secondary compensation is triggered to further optimize the phase consistency by precisely adjusting the axial position of the objective lens group and / or fine-tuning the inclination angle of the beam splitter;

[0133] Adjust the axial position of the objective lens group (for example: the step size ≤ Λ / 50);

[0134] Fine-tune the inclination angle of the beam splitter (for example: the adjustment range ≤ 0.1°).

[0135] The working principle and effect of the above technical solution are the same as those in the system embodiment of this application, and will not be elaborated here.

[0136] The embodiment of the present invention further provides an electronic device, the electronic device includes a memory and a processor, the memory stores a computer program, and when the processor executes the computer program, the steps of any one of the methods in the embodiments of this application are implemented.

[0137] The embodiment of this application further provides a computer-readable storage medium, which is used to store a computer program, and when the computer program is executed, the steps of any one of the methods in the embodiments of this application are implemented. The specific implementation manner is the same as the implementation manner and the achieved technical effect recorded in the above method embodiment, and some contents will not be elaborated.

[0138] In this application, the readable storage medium can be any tangible medium that contains or stores a program, and this program can be used by or in combination with an instruction execution system, apparatus, or device. The program product can adopt any combination of one or more readable media. The readable medium can be a readable signal medium or a readable storage medium. The readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the above. More specific examples (non-exhaustive list) of the readable storage medium include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0139] A computer-readable storage medium may include a data signal propagated in a baseband or as part of a carrier wave, in which a readable program code is carried. Such a propagated data signal may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the foregoing. The readable storage medium may also be any readable medium that can send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device. The program code contained on the readable storage medium may be transmitted using any appropriate medium, including but not limited to wireless, wired, optical fiber cable, RF, etc., or any suitable combination of the foregoing. The program code for performing the operations of the present invention may be written in any combination of one or more programming languages, including object-oriented programming languages such as Java, C++, etc., and also including conventional procedural programming languages such as the C language or similar programming languages. The program code may be executed entirely on the user computing device, partially on an associated device, executed as a stand-alone software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server. In the case of a remote computing device, the remote computing device may be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computing device (e.g., by using an Internet service provider to connect through the Internet).

[0140] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention, and all such changes should fall within the protection scope of the claims of the present invention.

Claims

1. Multi-channel parallel structure interference optical system, characterized in that The system comprises: A multi-channel parallel light source array includes a plurality of independently modulated sub-light sources, each of which contains at least dual-wavelength outputs, and generates an angle-integrated illumination beam along an angle θ with the main optical axis through a micro-concave mirror or an optical steering device to achieve spatial incoherent illumination; An interference optical path module, used to split the light beam from the multi-channel parallel light source array into a scene arm and a reference arm, and generate an interference light signal; The compound eye sensor array includes a plurality of monocular sensors, each monocular corresponds to a sub-light source of the multi-channel parallel light source array one by one, the light emitted by the multi-channel parallel light source array is processed by an interference optical path module and then emitted to the compound eye sensor array, and each monocular of the compound eye sensor array receives an interference light signal from a sub-light source and outputs an interference pattern.

2. The multi-channel parallel structure interference optical system according to claim 1, characterized in that, The method of generating an angle-integrated illumination beam along an angle θ with respect to the main optical axis by using a micro-concave mirror or an optical steering device comprises: Through a micro-concave mirror or an optical steering device, each sub-light source is scanned at an angle of θ to form spatial incoherent illumination; the scanning angle of each sub-light source is independently controllable; θ∈[-Θ / 2,Θ / 2]; Θ is the maximum scanning angle, which is determined by the emission area and the focal length of the lens; The integrated light beam reduces aberration through coaxial fiber coupling technology, and eliminates speckle noise through Gaussian low-pass filtering combined with bilateral filtering.

3. The multi-channel parallel structure interference optical system according to claim 1, characterized in that, The interference optical path module is based on the Michelson interferometer architecture, including a beam splitter, a scene arm objective, a reference arm translation mirror and an interference generator; the beam is split by the beam splitter, the scene arm objective is used to collect sample information, the reference arm translation mirror is used to adjust the optical path, and finally the two beams of light are used to achieve beam interference through the interference generator.

4. The multi-channel parallel interference optical system according to claim 3, characterized in that The monocular sensor surface of the compound eye sensor array is located at a conjugate position of the rear focal plane of the scene arm objective lens, receives interference light from the scene arm and the reference arm, and outputs an original image containing interference patterns of multiple sub-regions.

5. The multi-channel parallel interference optical system according to claim 1, characterized in that The sub-areas of the compound eye sensor array can overlap, and adjacent sub-areas are distinguished by differences in light source amplitude, wavelength or polarization; each single eye in the compound eye sensor array receives a corresponding channel signal; the phase solution depth is calculated in real time; and the overlapping area data is weightedly fused to eliminate splicing errors.

6. The multi-channel parallel structure interference optical system according to claim 1, characterized in that Each sub-light source of the multi-channel parallel light source array is an independent light emitter; or, Multiple sub-light sources are generated from the same initial light source through a beam splitter, a polarizer and a compensation plate.

7. The multi-channel parallel interference optical system according to claim 1, characterized in that, Each sub-light source generates a focused beam through a fiber coupler, a circulator and a collimator, illuminating only the corresponding conjugate points of the scene arm and the reference arm.

8. The multi-channel parallel structure interference optical system according to claim 1, characterized in that The system also includes an AI integrated algorithm processor for processing the signals collected by each sensor to form an overall image and result report.

9. The multi-channel parallel structure interference optical system according to claim 1, characterized in that, The system further includes a dynamic phase compensation module, wherein the phase compensation module is configured to: Extract the phase difference of adjacent channel interference signals through the redundant sub-regions of the compound eye sensor array Based on the phase difference Calculate the phase drift amount According to Compensate for the displacement of the translation mirror of the reference arm, synchronously adjust the wavelengths λ1 and λ2 of the sub-light sources, and keep the synthetic wavelength constant; After compensation, the phase consistency of the overlapping area is re-measured. If the residual phase error exceeds the preset threshold, the secondary compensation is triggered, and the phase consistency is further optimized by adjusting the axial position of the objective lens group and / or fine-tuning the inclination angle of the beam splitter.

10. An interference measurement method based on an interference optical system with a multi-channel parallel structure, characterized in that, The following steps are involved: A multi-channel parallel light source array is used to generate multiple independently modulated sub-light sources. Each sub-light source includes at least dual-wavelength output, and through a micro concave mirror or an optical steering device, each sub-light source generates an angle superposition and integration beam along an angle θ with the main optical axis, realizing spatial incoherent illumination; The light emitted by the multi-channel parallel light source array is introduced into an interference optical path module based on the Michelson interferometer architecture to form an interference optical signal; After the light emitted by the multi-channel parallel light source array is processed by the interference optical path module, it is projected onto a compound eye sensor array. Each single eye of the compound eye sensor array correspondingly receives the interference optical signal from a sub-light source and outputs an interference pattern; the compound eye sensor array includes multiple single-eye sensors, and each single eye corresponds one-to-one with the sub-light source of the multi-channel parallel light source array.

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