Phase detection method, electronic device and medium based on structured light phase shift

Abstract

The present invention discloses a phase detection method, an electronic device and a medium based on structured light phase shift. The method comprises: starting a laser transmitter to emit two reference light beams to generate an interference field on a sample surface; controlling the phases of the two reference light beams to be equal, scanning the interference field, and obtaining the intensity information of the first interference field; moving the initial phases of the two reference light beams forward by π / 2, scanning the interference field, and obtaining the intensity information of the second interference field; moving the initial phases of the two reference light beams forward by π / 2 again, scanning the interference field, and obtaining the intensity information of the third interference field; moving the phases of the two reference light beams forward by π / 2 again, scanning the interference field, and obtaining the intensity information of the fourth interference field; and calculating the phase distribution of the light field to be measured using the intensity information of the first, second, third and fourth interference fields. The phase detection method based on structured light phase shift of the present invention has the advantages of richer functions, simpler measurement system and more accurate phase recovery method.

Description

Technical Field

[0001] The present invention relates to the field of microscopic imaging, and in particular to a phase detection method, an electronic device and a medium based on structured light phase shift. Background Art

[0002] Optical microscopy is an imaging technology for detecting microscopic objects and parameters. Since its development, the theory and technology are very mature and it is widely used in various fields such as physics, chemistry, and biology. The measurement of light intensity, phase, polarization and other information is an important means for optical imaging technology to obtain information about the object to be measured. Among them, optical imaging technology based on intensity detection has a long history and relatively mature technology development. However, with the advent of the nano era, people are advancing to smaller scales and low-dimensional spaces in scientific and technological research. The precise detection and imaging of nano-scale objects has become an urgent need, but the resolution of traditional optical microscopy technology is limited by the optical diffraction limit and it has become increasingly difficult to meet the needs of researchers; In addition, intensity, as one of the basic physical quantities of light, is the way for most traditional optical imaging technologies to obtain information. However, intensity cannot fully reflect the physical properties of light, so the information transmission of the object to be measured is limited. For example, it is difficult for imaging technology based on intensity detection to obtain complex information such as the thickness, material, and optical refractive index of the object to be measured. These problems make it difficult for traditional microscopy imaging technology based on intensity detection to make breakthroughs in imaging technology with higher precision and more complex parameters. Subsequently, some microscopic imaging technologies that can greatly improve the performance of optical imaging have emerged, such as near-field scanning optical microscopy (NSOM), which collects or emits photons through a nanoscale detector close to the surface of the object, that is, the probe is coupled with a sub-wavelength-sized object deposited on the surface, thereby converting the near-field bound field carrying more information to the far field for collection, and then measuring the relevant information of the near-field object to be measured through precise scanning and feedback, with a resolution of up to tens of nanometers. However, most NSOMs are still based on intensity measurement, so it is still challenging to obtain richer information about the sample.

[0003] Phase, as one of the basic physical properties of light, reflects the spatiotemporal characteristics of the light field. If the phase can be measured, a large amount of information about the light field can be obtained, thereby broadening people's application scenarios of light. Therefore, it has gradually attracted the attention of relevant research in the field of optical imaging technology. Microscopic imaging based on phase detection is currently mainly applied in the field of biological imaging by combining with other imaging technologies. For example, in biomedical research, a new method of detecting biological tissue heterogeneity (tumor) by using near-infrared optical coherent phase array modulation method is studied by combining tissue near-infrared spectroscopy technology (NIRS). The biological tissue cell map imaged by this method can better reflect the relationship between the light field distribution and tissue characteristics. It is relatively easy to obtain optical phase information in free space, mainly by using structured light field and sample information for interference modulation, such as moiré profile technology, fringe projection profile, etc. However, it is difficult to obtain optical phase information in the near field range. The current technology that can measure the phase of the light field is based on NSOM for heterodyne interference modulation and demodulation. This technology requires the introduction of a relatively complex interference system, and the extraction of phase requires a strict demodulation method, which greatly limits its scope of application. In summary, developing phase detection technology with richer functions, simpler measurement systems, and more accurate phase recovery methods has far-reaching scientific significance and huge application value. Summary of the invention

[0004] The main purpose of the present invention is to provide a phase detection method, an electronic device and a medium based on structured light phase shift, which have the advantages of richer functions, a simpler measurement system and a more accurate phase recovery method.

[0005] To achieve the above-mentioned purpose, the first aspect of the present invention provides a phase detection method based on structured light phase shift, including: starting a laser transmitter to emit two beams of reference light to generate an interference field on the sample surface; using a spatial light modulator to control the phases of the two beams of reference light to be equal, the phase is recorded as φ, scanning the interference field, and obtaining the intensity information of the first interference field; adjusting the spatial light modulator so that the initial phases of the two beams of reference light move forward by π / 2, the phase is recorded as φ+π / 2, scanning the interference field again, and obtaining the intensity information of the second interference field; adjusting the spatial light modulator so that the initial phases of the two beams of reference light move forward by π / 2 again, the phase is recorded as φ+π, scanning the interference field again, and obtaining the intensity information of the third interference field; adjusting the spatial light modulator so that the phases of the two beams of reference light move forward by π / 2 again, the phase is recorded as φ+3π / 2, scanning the interference field again, and obtaining the intensity information of the fourth interference field; using the intensity information of the first, second, third, and fourth interference fields to calculate the phase distribution of the light field to be measured.

[0006] Furthermore, the interference field generation method includes: using two beams of the reference light to form structured light stripes on the sample surface, and generating an interference field after the two beams of the reference light interfere with the light field to be measured on the sample surface, wherein the light field to be measured is E i The structured light fringes formed by the two reference lights are the first light field E1 and the second light field E2, and the light field distribution of the interference field is E t .

[0007] Furthermore, the method for calculating the intensity information of the interference field includes: using the light field distribution of the interference field to calculate the light field intensity of the interference field, and obtaining a first expression for the light field intensity of the interference field; controlling the amplitudes of the two reference light beams to be the same, calculating the first expression, and obtaining a second expression for the light field intensity of the interference field; setting the initial phases of the two reference light beams to be the same, calculating the second expression, and obtaining a third expression for the interference field; using the third expression, calculating the intensity information of the new field distribution after the light field to be measured with the initial phase Φ interferes with the two reference light beams, and obtaining the intensity information calculation relationship E of the interference field. t (Φ).

[0008] Furthermore, the method for calculating the phase distribution of the light field to be measured includes: calculating a relationship based on the intensity information of the interference field to obtain the intensity information of the first, second, third, and fourth interference fields; using the intensity information of the first interference field to subtract the intensity information of the third interference field to obtain a first difference expression; using the intensity information of the second interference field to subtract the intensity information of the fourth interference field to obtain a second difference expression; combining the first difference expression and the second difference expression to calculate the phase distribution of the light field to be measured.

[0009] Furthermore, the light field to be measured E i , the first light field E1, the second light field E2 and the light field distribution E of the interference field t The expressions are:

[0010]

[0011]

[0012]

[0013] Where v represents the amplitude, k sp represents the wave vector, represents the initial phase of the reference light;

[0014]

[0015] Furthermore, the first expression is:

[0016]

[0017] The phase detection method based on structured light phase shift further includes: simplifying the first expression to obtain:

[0018]

[0019] By controlling the amplitudes of the two reference lights to be the same, v1=v2=v is obtained, and the second expression is:

[0020]

[0021] The initial phases of the two reference beams are the same, Φ, and we get The third expression is:

[0022]

[0023] The intensity information of the interference field is calculated by the equation E t (Φ) is:

[0024]

[0025] Further, the relationship E is calculated according to the intensity information of the interference field t (Φ), the expressions for the intensity information of the first, second, third, and fourth interference fields are obtained as follows:

[0026]

[0027]

[0028]

[0029]

[0030] The first difference expression is:

[0031]

[0032] The second difference expression is:

[0033]

[0034] The phase distribution of the light field to be measured for

[0035]

[0036] A second aspect of the present invention provides an electronic device, comprising: a memory and a processor, wherein the memory stores a computer program that can be run on the processor, and when the processor executes the computer program, any one of the above-mentioned phase detection methods based on structured light phase shift is implemented.

[0037] A third aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, any one of the above-mentioned phase detection methods based on structured light phase shift is implemented.

[0038] The present invention provides a phase detection method, an electronic device and a medium based on structured light phase shift, which have the beneficial effects of being able to introduce the structured light detection method in free space into the near-field scanning technology, by using two reference light beams to generate an evanescent wave structured light field on the sample surface, and being able to use a spatial light modulator to adjust the initial phase of the reference light, by changing the initial phase of the structured light field multiple times, and then using an accurate analytical method, the phase distribution of the light field to be measured can be accurately solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0040] Figure 1 Schematic diagram of a phase detection method based on structured light phase shift according to an embodiment of the present invention;

[0041] Figure 2 Schematic diagram of the structure of a phase detection system based on structured light phase shift according to an embodiment of the present invention;

[0042] Figure 3 This is a verification diagram of the phase detection method based on structured light phase shift according to an embodiment of the present invention;

[0043] Figure 4 The figure is a schematic block diagram of the structure of an electronic device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0044] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0045] See also Figure 1 , which is a phase detection method based on structured light phase shift, comprising:

[0046] S101, start the laser transmitter to emit two reference beams to generate an interference field on the sample surface;

[0047] S102, using a spatial light modulator to control the phases of the two reference beams to be equal, the phase is recorded as φ, scanning the interference field, and obtaining the intensity information of the first interference field;

[0048] S103, adjusting the spatial light modulator so that the initial phase of the two reference light beams moves forward by π / 2, the phase is recorded as φ+π / 2, and the interference field is scanned again to obtain the intensity information of the second interference field;

[0049] S104, adjusting the spatial light modulator so that the initial phases of the two reference light beams are moved forward by π / 2 again, the phases are recorded as φ+π, and the interference field is scanned again to obtain the intensity information of the third interference field;

[0050] S105, adjusting the spatial light modulator so that the phases of the two reference light beams move forward by π / 2 again, the phases are recorded as φ+3π / 2, and the interference field is scanned again to obtain the intensity information of the fourth interference field;

[0051] S106. Calculate the phase distribution of the light field to be measured using the intensity information of the first, second, third and fourth interference fields.

[0052] In steps S102 and S013, a photomultiplier tube may be used to scan the light beam currently transmitted to the photomultiplier tube to obtain the intensity information of the first and second interference fields.

[0053] In one embodiment, the method for generating an interference field includes: using two reference light beams to form structured light fringes on the sample surface, and generating an interference field after the two reference light beams interfere with the light field to be measured on the sample surface, wherein the light field to be measured is E i The structured light fringes formed by the two reference beams are the first light field E1 and the second light field E2, and the light field distribution of the interference field is E t .

[0054] In this embodiment, the light field to be measured Ei The expression is:

[0055]

[0056] Then, the structured light stripes are formed by introducing two reference beams, which can be written as:

[0057]

[0058]

[0059] Where v represents the amplitude, k sp represents the wave vector, represents the initial phase of the reference light;

[0060] When the two reference beams E1 and E2 interfere with the light field to be measured, a new interference field distribution E is formed. t , then E t The mathematical expression is:

[0061]

[0062] In one embodiment, the method for calculating the intensity information of the interference field includes:

[0063] The light field intensity of the interference field is calculated using the light field distribution of the interference field, and a first expression of the light field intensity of the interference field is obtained;

[0064] The amplitudes of the two reference beams are controlled to be the same, and the first expression is calculated to obtain the second expression of the light field intensity of the interference field;

[0065] Set the initial phases of the two reference beams to be the same, calculate the second expression, and obtain the third expression of the interference field;

[0066] Using the third expression, the intensity information of the new field distribution after the interference between the measured light field with the initial phase Φ and the two reference beams is calculated, and the intensity information calculation relation E of the interference field is obtained. t (Φ).

[0067] In this embodiment,

[0068] The first expression is:

[0069]

[0070] The phase detection method based on structured light phase shift also includes: simplifying the first expression to obtain:

[0071]

[0072] By controlling the amplitudes of the two reference beams to be the same, we can obtain v1=v2=v, and the second expression is:

[0073]

[0074] The initial phases of the two reference beams are the same, Φ, and we get The third expression is:

[0075]

[0076] The calculation formula of the intensity information of the interference field is E t (Φ) is:

[0077]

[0078] In one embodiment, a method for calculating the phase distribution of the light field to be measured includes:

[0079] According to the intensity information of the interference field, a relationship is calculated to obtain the intensity information of the first, second, third and fourth interference fields;

[0080] Subtracting the intensity information of the third interference field from the intensity information of the first interference field to obtain a first difference expression;

[0081] Subtracting the intensity information of the fourth interference field from the intensity information of the second interference field to obtain a second difference expression;

[0082] The first difference expression and the second difference expression are combined to calculate the phase distribution of the light field to be measured.

[0083] In this embodiment, the relationship E is calculated based on the intensity information of the interference field. t (Φ), the expressions for the intensity information of the first, second, third, and fourth interference fields are obtained as follows:

[0084]

[0085]

[0086]

[0087]

[0088] The first difference expression is:

[0089]

[0090] The second difference expression is:

[0091]

[0092] Phase distribution of the light field to be measured for

[0093]

[0094] In one embodiment, a method for calculating the phase distribution of a light field to be measured includes: pre-constructing a mathematical expression for the light field on the surface of a sample; expressing two reference light beams by means of a mathematical expression to obtain a first reference light formula and a second reference light formula; after the two reference light beams interfere with the surface light field of the sample, using the mathematical expression, the first reference light formula and the second reference light formula to calculate a distribution expression of the interference field; using the distribution expression of the interference field to calculate the light field intensity of the interference field to obtain a light field intensity formula; controlling the amplitudes of the two reference light beams to be the same to simplify the light field intensity formula; setting the initial phases of the two reference light beams to be the same as Φ; simplifying the light field intensity formula again according to the initial phase; using phases φ, φ+π / 2, φ+π, and φ +3π / 2 to perform calculations in the light field intensity formula to obtain the phase of the light field to be measured.

[0095] In one embodiment, the mathematical expression of the light field on the sample surface is:

[0096]

[0097] The first reference light formula and the second reference light formula are:

[0098]

[0099]

[0100] Where v represents the amplitude, k sp represents the wave vector, represents the initial phase of the reference light;

[0101] The distribution expression of the interference field is:

[0102]

[0103] The formula for light field intensity is:

[0104]

[0105] If the amplitudes of the two reference beams are controlled to be the same, then v1 = v2 = v, and the simplified formula for the light field intensity is:

[0106]

[0107] When the initial phases of the two reference beams are the same as Φ, then The light field intensity formula is simplified again:

[0108]

[0109] According to the light field intensity formula, the intensity relationship of the new field distribution Et(Φ) after the interference of the measured light field with the initial phase Φ and the two reference beams is obtained:

[0110]

[0111] In this embodiment, in actual measurement, the easiest thing to measure is the intensity distribution diagram of the light field, and E t (Φ) reflects that the intensity distribution and phase of the light field are related to each other. Therefore, in the process of phase detection, it is also necessary to determine the phase of the field to be measured by scanning the light field intensity. First, a spatial light modulator (SLM) is used to control the phase of the two reference beams through refractive index modulation to achieve phase shift, and the interference field intensity after each modulation is measured. After precise analytical calculation, the phase distribution of the light field to be measured is finally obtained.

[0112] In the phase shift process, the spatial light modulator first controls the initial phases of the two reference beams to be the same, denoted as Φ, and scans the intensity distribution of the interference field, denoted as I1. The mathematical expression is:

[0113]

[0114] Then the initial phase Φ of the reference light is changed in turn to Φ+π, Each time the initial phase is changed, the intensity distribution of the interference field is scanned once and recorded as I2, I3, and I4 respectively. The mathematical expression is:

[0115]

[0116]

[0117]

[0118] According to the intensity distribution formula of the four interference fields, we can get:

[0119]

[0120]

[0121] According to the intensity distribution formula of the four interference fields, the phase of the field to be measured can be calculated as:

[0122]

[0123] The phase detection method based on structured light phase shift provided in this embodiment can introduce the structured light detection method in free space into the near-field scanning technology. By using two beams of reference light to generate an evanescent wave structured light field on the sample surface, and being able to use a spatial light modulator to adjust the initial phase of the reference light, by changing the initial phase of the structured light field multiple times, and then using a precise analytical method, the phase distribution of the light field to be measured can be accurately solved. The advantage of this method is that near-field detection can provide high resolution, phase extraction does not require complex algorithm support but has a clear analytical formula, and can achieve phase detection of different polarization components by adjusting the polarization selection function of near-field scanning. In general, this is a technology that can break through many current phase detection problems, and is expected to be applied to scientific research related to the study and characterization of near-field optical physical properties, and has broad application prospects.

[0124] In one embodiment, the phase detection method based on structured light phase shift also includes: verifying the calculated phase of the field to be measured, and the verification method includes: setting a light field to be measured with a known phase distribution; obtaining a known actual phase distribution diagram based on the light field to be measured; calculating the calculated phase distribution diagram of the light field to be measured; using the actual phase diagram to perform point-by-point phase subtraction on the calculated phase distribution diagram to obtain a result diagram; and verifying the calculated phase of the field to be measured based on the result diagram.

[0125] In this embodiment, a simulation verification is carried out on MATLAB. First, assume that the light field to be measured is as shown in FIG2-(a), where λ sp 600nm, k sp =2π / λ sp . Figure 2 -(b) is the phase distribution of the light field to be measured. Figure 2 -(c) is the phase distribution of the measured light field calculated using the above algorithm. It is preliminarily inferred that the calculated phase distribution is consistent with the original phase distribution of the measured light field. Figure 2 -(d) It is more intuitive to illustrate that the phase distribution calculated by the algorithm is exactly the phase distribution of the original light field to be measured, which means that it is feasible to use the algorithm to calculate the phase distribution of the light field.

[0126] In one embodiment, a supporting optical path system capable of implementing the phase detection method based on structured light phase shift in any of the above embodiments is also provided, specifically a phase detection system based on structured light phase shift, see Figure 3, including: a laser emitter 1, a beam expansion module 2, a first beam splitter 3, a second beam splitter 4, a vortex half-wave plate 5, a third beam splitter 6, a first half-wave plate 7, a spatial light modulator 8, a reference light transmission module 9, a first objective lens 10, a first CCD camera 11, a second objective lens 12, a fourth beam splitter 13, a second lens 14, a photomultiplier tube 15, a third lens 16 and a second CCD camera 17.

[0127] Among them, the laser transmitter 1 is used to emit laser; the beam expansion module 2 is used to expand the laser emitted by the laser transmitter 1; the first beam splitter 3 is used to split the laser expanded by the beam expansion module 2 into two laser beams, the first laser of the two laser beams is used to excite the excitation light of the light field to be measured, and the second laser beam is used to generate two reference beams that interfere with the light field to be measured; the second beam splitter 4 is used to pass the first laser beam; the vortex half-wave plate 5 is used to polarization modulate the first laser beam passing through the second beam splitter 4; the third beam splitter 6 is used to divide the first laser beam polarization modulated by the vortex half-wave plate 5 into two laser beams, namely the first detection light and the second detection light; the first half-wave plate 7 is used to polarization modulate the second laser beam split by the first beam splitter 3;

[0128] The spatial light modulator 8 is used to modulate the second laser beam polarization-modulated by the first half-wave plate 7 into two reference beams with specific initial phases for interference required for phase detection. The second beam splitter 4 is also used to reflect the two reference beams to the vortex half-wave plate. The vortex half-wave plate 5 is also used to polarization-modulate the two reference beams. The third beam splitter 6 is also used to separate the two reference beams after polarization modulation into two reference laser beams respectively. The reference light transmission module 9 is used to transmit the two reference beams from the spatial light modulator 8 to the second beam splitter 4.

[0129] The first objective lens 10 is used to focus the first detection light to the sample surface, and to focus the first reference laser beam split from the two reference light beams to the sample surface; the first CCD camera 11 is used to receive the second detection light and the second reference laser beam split from the two reference light beams; the second objective lens 12 is used to collect the light beam passing through the sample; the fourth beam splitter 13 is used to split the light beam collected by the second objective lens 12 into a third laser beam and a fourth laser beam; the second lens 14 is used to focus the third laser beam; the photomultiplier tube 15 is used to receive the third laser beam focused by the second lens 14; the third lens 16 is used to focus the fourth laser beam; the second CCD camera 17 is used to receive the fourth laser beam focused by the third lens 16.

[0130] In this embodiment, the laser emitted by the laser is first expanded by the beam expansion module 2, and then divided into two paths by the first beam splitter 3, one path is used to excite the excitation light of the light field to be measured, and the other path is used to generate two reference lights that interfere with the light field to be measured. The detection light used to excite the light field to be measured first passes through the second beam splitter 4, and is polarization modulated by the vortex half-wave plate 5, and then is divided into two paths by the third beam splitter 6, one path is focused on the sample surface through the objective lens, and a first CCD camera 11 is placed at the end of the other path to observe the detection light and the two reference lights; at the same time, the second path of light separated by the first beam splitter 3 is polarization modulated by the half-wave plate, and then modulated by the spatial light modulator 8 to be divided into two beams of light with a specific initial phase for interference required for phase detection, and after being polarization modulated by the vortex half-wave plate 5, it is focused on the sample surface by the objective lens, interference fringes are generated on the surface, and a counter transmission is formed.

[0131] The upper half of the sample is the collection and detection part: after the lower half of the sample is excited to generate a structured light field, it is collected and detected by the equipment on the upper half. The upper half of the light beam is collected by the objective lens, and then divided into two paths through the fourth beam splitter 13. One path is composed of a second lens 14 and a photomultiplier tube 15, which is used to collect the intensity of the interference field and realize the characterization of the light field intensity information; the other path contains a third lens 16 and a second CCD camera 17 for observing the alignment of the sample and the light field. In this embodiment, during the measurement process, it is necessary to scan at least four times to obtain the intensity distribution of the four interference fields: the first time, the two reference light beams are controlled to have equal phases through the spatial light modulator 8, which is recorded as φ, and the intensity information of the interference field at this time is obtained by scanning; the second time, the spatial light modulator 8 is adjusted so that the initial phase of the reference light moves forward by π / 2, which is recorded as φ+π / 2, and the intensity information of the interference field at this time is obtained by scanning; the third time, the spatial light modulator 8 is adjusted so that the initial phase of the reference light moves forward by π / 2, which is recorded as φ+π, and the intensity information of the interference field at this time is obtained by scanning; the fourth time, the spatial light modulator 8 is adjusted so that the initial phase of the reference light moves forward by π / 2, which is recorded as φ+3π / 2, and the intensity information of the interference field at this time is obtained by scanning. Finally, the phase distribution φ of the light field to be measured is obtained by mathematical calculation through the formula in the previous text.

[0132] The phase detection system based on structured light phase shift provided in this embodiment can introduce the structured light detection method in free space into the near-field scanning technology, by using two beams of reference light to generate an evanescent wave structured light field on the sample surface, and by using the spatial light modulator 8 to adjust the initial phase of the reference light, by changing the initial phase of the structured light field multiple times, and then using a precise analytical method, the phase distribution of the light field to be measured can be accurately solved. The advantage of this method is that near-field detection can provide high resolution, phase extraction does not require complex algorithm support but has a clear analytical formula, and can achieve phase detection of different polarization components by adjusting the polarization selection function of the near-field scanning. In general, this is a technology that can break through many current phase detection problems, and is expected to be applied to scientific research related to the study and characterization of near-field optical physical properties, and has broad application prospects.

[0133] In one embodiment, the beam expansion module 2 includes: a first lens 2a and a beam expander 2b, the first lens 2a is arranged between the beam expander 2b and the laser emitter 1, and the beam expander 2b is arranged on the side of the focus of the first lens 2a away from the laser emitter 1.

[0134] In this embodiment, after passing through the first lens 2a and the beam expander 2b, the laser can form a stable and wide light beam, thereby facilitating the laser beam splitting process in the subsequent process.

[0135] In one embodiment, the reference light transmission module 9 includes: a mask 18, a second half-wave plate 19, a fourth lens 20 and a fifth lens 21; the two reference light beams pass through the mask 18, the second half-wave plate 19, the fourth lens 20 and the fifth lens 21 in sequence, and are transmitted to the second beam splitter 4, and the fifth lens 21 is arranged on the side of the fourth lens 20 away from the focus of the fourth lens 20.

[0136] In this embodiment, the second beam splitter 4 is located on a side of the fifth lens 21 where the focus is close to the fifth lens 21 , so that the fifth lens 21 reflects the two reference beams before focusing them.

[0137] In one embodiment, the phase detection system based on structured light phase shift further includes: a sixth lens 22 for focusing the second detection light and the second reference laser beam obtained by splitting the two reference light beams onto the first CCD camera 11 .

[0138] In one embodiment, in order to facilitate the propagation of the light beam, save space, etc., a reflector 23 can be set at any position of the phase detection system based on structured light phase shift. For example, a reflector 23 is set between the first half-wave plate 7 and the spatial light modulator 8. It can change the propagation direction of the light beam without affecting the propagation of the light beam, thereby saving space for the phase detection system based on structured light phase shift.

[0139] In the above embodiments, all the lenses involved are convex lenses.

[0140] The present application embodiment provides an electronic device, see Figure 4 The electronic device includes: a memory 601, a processor 602, and a computer program stored in the memory 601 and executable on the processor 602. When the processor 602 executes the computer program, the phase detection method based on structured light phase shift described above is implemented.

[0141] Furthermore, the electronic device also includes: at least one input device 603 and at least one output device 604 .

[0142] The memory 601 , processor 602 , input device 603 and output device 604 are connected via a bus 605 .

[0143] The input device 603 may be a camera, a touch panel, a physical button or a mouse, etc. The output device 604 may be a display screen.

[0144] The memory 601 may be a high-speed random access memory (RAM) memory, or a non-volatile memory, such as a disk memory. The memory 601 is used to store a set of executable program codes, and the processor 602 is coupled to the memory 601 .

[0145] Furthermore, an embodiment of the present application further provides a computer-readable storage medium, which may be disposed in the electronic device in each of the above embodiments, and the computer-readable storage medium may be the aforementioned memory 601. The computer-readable storage medium stores a computer program, and when the program is executed by the processor 602, the phase detection method based on structured light phase shift described in the above embodiments is implemented.

[0146] Furthermore, the computer storable medium may also be a U disk, a mobile hard disk, a read-only memory 601 (ROM), a RAM, a magnetic disk or an optical disk, and other media that can store program codes.

[0147] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0148] The above is a description of a phase detection method, electronic device and medium based on structured light phase shift provided by the present invention. For those skilled in the art, according to the ideas of the embodiments of the present invention, there may be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A phase detection method based on structured light phase shift, characterized in that: include: Start the laser transmitter and emit two reference beams to generate an interference field on the sample surface; The spatial light modulator is used to control the phases of the two reference beams to be equal. The phase is recorded as , scanning the interference field to obtain the intensity information of the first interference field; The spatial light modulator is adjusted so that the initial phase of the two reference beams moves forward by π / 2, and the phase is recorded as +π / 2, scan the interference field again to obtain the intensity information of the second interference field; The spatial light modulator is adjusted so that the initial phases of the two reference beams are moved forward by π / 2 again, and the phases are recorded as +π, scan the interference field again to obtain the intensity information of the third interference field; Adjust the spatial light modulator so that the phase of the two reference beams moves forward by π / 2 again, and the phase is recorded as +3π / 2, scan the interference field again to obtain the intensity information of the fourth interference field; The phase distribution of the light field to be measured is calculated using the intensity information of the first, second, third and fourth interference fields; The method for generating the interference field comprises: using two beams of the reference light to form structured light stripes on the sample surface, and generating an interference field after the two beams of the reference light interfere with the light field to be measured on the sample surface, wherein the light field to be measured is The structured light stripes formed by the two reference beams are the first light field and the second light field , the light field distribution of the interference field is ; The calculation method of the intensity information of the interference field includes: Calculate the light field intensity of the interference field using the light field distribution of the interference field to obtain a first expression for the light field intensity of the interference field; Controlling the amplitudes of the two reference lights to be the same, calculating the first expression, and obtaining a second expression for the light field intensity of the interference field; Setting the initial phases of the two reference lights to be the same, calculating the second expression, and obtaining a third expression of the interference field; Using the third expression, calculate the initial phase Φ The intensity information of the new field distribution after the measured light field interferes with the two reference lights, and the intensity information calculation relationship of the interference field is obtained: ; The method for calculating the phase distribution of the light field to be measured includes: Calculating a relationship according to the intensity information of the interference field to obtain the intensity information of the first, second, third, and fourth interference fields; Subtracting the intensity information of the third interference field from the intensity information of the first interference field to obtain a first difference expression; Subtracting the intensity information of the fourth interference field from the intensity information of the second interference field to obtain a second difference expression; The first difference expression and the second difference expression are combined to calculate the phase distribution of the light field to be measured.

2. The phase detection method based on structured light phase shift according to claim 1, characterized in that: The light field to be measured , the first light field The second light field and the light field distribution of the interference field The expressions are: in represents the amplitude, represents the wave vector, represents the initial phase of the reference light; 。 3. The phase detection method based on structured light phase shift according to claim 2, characterized in that: The first expression is: The phase detection method based on structured light phase shift further includes: simplifying the first expression to obtain: By controlling the amplitudes of the two reference lights to be the same, v1=v2=v is obtained, and the second expression is: The initial phases of the two reference beams are the same, Φ, and we get , the third expression is: The intensity information calculation relationship of the interference field is: for:

4. The phase detection method based on structured light phase shift according to claim 3, characterized in that: The relationship is calculated based on the intensity information of the interference field , the expressions for the intensity information of the first, second, third, and fourth interference fields are obtained respectively: The first difference expression is: The second difference expression is: The phase distribution of the light field to be measured for 。 5. An electronic device comprising: A memory and a processor, wherein the memory stores a computer program executable on the processor, wherein when the processor executes the computer program, the method described in any one of claims 1 to 4 is implemented.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method described in any one of claims 1 to 4 is implemented.

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