A white light Mach interferometer and its use method

Abstract

The present invention discloses a white light Mach interferometer and a method for using the same, belonging to the field of optical detection technology. The device includes a structural component, including an optical plate, a support frame, cage rods, and a cage frame; a projection component, including a light source, a first beam splitter prism, a second beam splitter prism, a third beam splitter prism, and a beam combining prism; an optical path adjustment mechanism; a Schlieren observation component, including a blade holder, and an observation camera; and a detection group mounting component, including an experimental group frame and a control group frame. The white light Mach interferometer uses a white light source to effectively overcome the speckle noise and phase jump problems of the laser interferometer, and is equipped with a flexible optical path adjustment mechanism to ensure consistent light phase, thereby improving the clarity and measurement accuracy of the interference pattern. In addition, the added Schlieren observation component combined with a CCD camera can clearly capture interference fringes, improve the clarity and contrast of interference, and facilitate data recording and analysis.

Description

Technical Field

[0001] The present invention relates to the field of optical detection technology, and in particular to a white light Mach interferometer and a method for using the same. Background Art

[0002] The Mach interferometer is a high-precision optical measurement tool. Due to its high sensitivity and accuracy, the Mach interferometer is widely used in fields such as refractive index measurement of liquids and gases and holography. Its basic structure consists of two beam splitters and two mirrors. The light beam emitted by the light source first passes through the first beam splitter and is divided into two parts: one part of the light beam goes straight through the area to be measured, and the other part of the light beam is reflected as a reference light. After the two light beams are reflected again, they are merged by the second beam splitter to form an interference pattern. Due to the uneven refractive index or thickness of the area to be measured, the phase of the light beam will change, thereby causing interference when it meets the reference light, which is ultimately manifested in the form of light intensity.

[0003] However, existing interferometry technology also faces some challenges. Current refractive index measurement and holography both use lasers as light sources. However, lasers have the problem of large speckle noise during actual measurement. This is mainly due to the narrow bandwidth and strong coherence of laser light sources. When the phase difference introduced by the refractive index of adjacent regions is an integer multiple of the wavelength of the light source, and the refractive index change has a jump characteristic, the interferometer will not be able to effectively distinguish the difference between the two regions, which reduces the observation accuracy in practical applications. Compared with lasers, white light has a shorter coherence length. White light interferometry can effectively solve the speckle and phase jump problems caused by laser interference. However, when using white light, if the optical path error between the two beams is large, clear interference fringes are often unable to form, resulting in a high requirement for the optical path difference. The existing Mach interferometer structure lacks an effective optical path difference adjustment mechanism. Therefore, to solve the above problems, we propose a white light Mach interferometer and its use method. Summary of the Invention

[0004] The purpose of the present invention is to provide a white light Mach interferometer and a method for using the same, aiming to improve measurement accuracy, overcome the defects of white light interference, and solve the problem of optical path error to meet the needs of practical applications.

[0005] To solve the above technical problems, the present invention provides a white-light Mach interferometer and a method for using the same, comprising a structural assembly, wherein the structural assembly includes an optical plate, a plurality of support frames mounted on the optical plate, the support frames being connected by cage rods, and a plurality of cage frames being connected in series on the cage rods. The support frames and the cage rods jointly support various components of the white-light Mach interferometer.

[0006] A projection assembly, comprising a light source, a first beam-splitting prism, a second beam-splitting prism, a third beam-splitting prism, and a beam-combining prism. The light source uses white light for interference. The second and third beam-splitting prisms face the two directions of light split by the first beam-splitting prism, respectively. The light is reflected by a reflector and converged to the beam-combining prism.

[0007] an optical path adjustment mechanism, each of which is disposed on one side of the second beam splitter prism and the third beam splitter prism, and is used to adjust the optical path difference and enhance the contrast of the interference pattern;

[0008] A Schlieren observation assembly includes a blade holder and an observation camera disposed on one side of the blade holder for observing interference fringes;

[0009] The blade holder is arranged between the beam combining prism and the observation camera, and the blade holder includes an adjustable blade, which is perpendicular to the light beam emitted by the beam combining prism and is located in the light path and can cut off a part of the light beam;

[0010] The detection group mounting component includes an experimental group frame arranged between the second beam splitter prism and the beam combining prism, and a control group frame arranged between the third beam splitter prism and the beam combining prism.

[0011] Preferably, a plurality of threaded holes are arranged in an array on the optical plate, and the support frame is fixedly mounted on the optical plate by bolts.

[0012] Preferably, the first beam splitter prism, the second beam splitter prism, the third beam splitter prism, and the beam combining prism are all installed in a cage frame, and the cage frame is a regular cube structure with passages opened on its edges and detachably connected in series with the cage rods.

[0013] Preferably, the beam combining prism reflects the light beam to the schlieren observation assembly through a reflector.

[0014] Preferably, the reflector includes a light angle adjustment member arranged on one side thereof.

[0015] Preferably, the optical path adjustment mechanism includes a fixed surface, an adjustment surface arranged parallel to the fixed surface, a hand-tightened thread pair arranged on the surface of the fixed surface and tightened diagonally, and a light-adjusting mirror arranged on one side of the adjustment surface;

[0016] The optical path adjustment mechanism is connected in series with the cage rod through the mounting hole, and the mounting hole is tightened by screws to press the top block against the cage rod to fix the optical path adjustment mechanism on the cage rod.

[0017] Preferably, the blade holder also includes adjusting screws arranged on its two end faces, the adjusting screws are used to adjust the cross-sectional area of ​​the adjustable blade, and the four corners of the blade holder are provided with through holes for connecting the cage rods in series. The through holes are connected to the adjustment gap, and the gap is tightened by tightening bolts to fix the blade holder.

[0018] Preferably, the observation camera is a CCD camera, and the CCD target surface is used to capture light interference signals to form interference fringes.

[0019] Preferably, a cuvette containing a sample to be tested is installed in the experimental group rack, and a vacuum cuvette for control is installed in the control group rack, and the installation angles and relative installation positions of the two cuvettes are consistent.

[0020] The present invention also provides a method for using a white light Mach interferometer, comprising the following steps:

[0021] Step A: optical path calibration;

[0022] Step A1: A light source emits a white light beam which is split into two beams by a first beam splitter prism, one of which is a transmitted light beam L1 and the other is a reflected light beam L2;

[0023] Step A2: The transmitted light beam L1 passes directly through the first beam-splitting prism and is directed to the second beam-splitting prism. First, the second beam-splitting prism will direct the light into the dichroic mirror on one side of the second beam-splitting prism. By adjusting the position of the adjustment surface on the cage rod and fine-tuning the hand-screwed pair to change the mirror angle, the light is reflected back to the second beam-splitting prism through the adjustment surface. Finally, it is reflected 90 degrees by the second beam-splitting prism into the beam-combining prism.

[0024] Step A3: The reflected light beam L2 is reflected 90 degrees by the first beamsplitter prism to the third beamsplitter prism. The third beamsplitter prism first reflects the light into the dichroic mirror on one side of the third beamsplitter prism. By adjusting the position of the adjustment surface on the cage rod and fine-tuning the hand-tightening threaded pair to change the mirror angle, the light is reflected back to the third beamsplitter prism through the adjustment surface and finally directly enters the beam-combining prism through the third beamsplitter prism. In this step, the optical path of the light beam in the third beamsplitter prism must be equal to the optical path of the light beam in the second beamsplitter prism.

[0025] Step A4: Adjust the optical angle adjustment component so that the combined light beams are reflected by the reflector onto the CCD target surface of the observation camera. The phases of the two combined light beams observed by the observation camera should be in phase. After eliminating the influence of external environmental factors such as air, fine-tune the position and angle of the two dimmers and the reflector. If the phases are inconsistent, adjust the dimmer angles. If the image is unclear, adjust the position of the optical path adjustment mechanism on the cage rods. Repeat steps A2 and A3 until the phases of the two combined light beams are consistent and the image is clear. The optical path calibration is complete.

[0026] Step B: Schlieren observation component adjustment;

[0027] Step B1: Adjust the optical path so that the light beam passes through the blade holder correctly;

[0028] Step B2: Adjust the adjusting screw to adjust the angle and position of the cutting blade to adjust the light-cutting area of ​​the adjustable blade to optimize the contrast and clarity of the interference fringes;

[0029] Step B3: Capture the interference pattern through the CCD target surface of the observation camera, observe the pattern and fine-tune the adjustment screw, camera focus and blade holder position simultaneously until the camera can clearly record the interference fringes after Schlieren processing, and the Schlieren observation component adjustment is completed;

[0030] Step C: comparative experiment;

[0031] Step C1: In steps A and B, only the experimental and control racks are located along the path from light splitting to beam combining, with no test components installed. In this step, a cuvette containing the sample to be tested is installed in the experimental rack, and a vacuum cuvette is installed in the control rack as a control. The two cuvettes must be installed at the same angle and relative position to ensure that light can pass through the cuvettes and enter the beam combining prism.

[0032] Step C2: Observe the interference fringes of the two light beams in the experimental group and the control group through the observation camera. The phase information is expressed in the form of light intensity. The frequency changes with the wavelength of the light source as the period, and the change of refractive index can be intuitively seen;

[0033] Step D: Data recording and analysis;

[0034] Step D1: Save the interference pattern image and record the experimental parameters (light source type, blade angle, camera settings, optical path adjustment mechanism position, etc.) for subsequent analysis. The use of the white light Mach interferometer is completed.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] 1. The white-light Mach interferometer of the present invention uses white light as a light source, overcoming the speckle noise and phase jump problems commonly found in laser interferometers. Furthermore, an optical path adjustment mechanism is added to overcome white light defects. The optical path adjustment mechanism can be adjusted by manually tightening a threaded pair. Manually adjusting and locking the position of the optical path adjustment mechanism on the cage rod allows for flexible adjustment of the optical path during the experiment, ensuring consistency in the phases of the two beams, ensuring clarity and contrast in the interference pattern, and significantly improving measurement accuracy and stability.

[0037] 2. The present invention adds a schlieren observation component to a white-light Mach interferometer. Combined with a CCD camera, the schlieren observation component can clearly capture interference fringes through schlieren, facilitating subsequent data recording and analysis, and improving the convenience and effectiveness of experimental operations. The schlieren observation component also has multiple adjustment angles and cross-sectional area adjustment functions, allowing for flexible angle adjustments during use to ensure that the camera can clearly record the interference fringes after schlieren processing.

[0038] 3. A white light Mach interferometer and its use method of the present invention first calibrate the optical path and the schlieren image, adjust the optical path to a position where the interference image can be clearly produced, calibrate the optical path by checking whether the phase of the CCD target surface light is consistent, and then use the optical phase interference generated between the optical paths of the experimental group frame and the control group frame, while introducing schlieren as an auxiliary means, to intuitively see the change in refractive index. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a schematic diagram of the overall structure of a white light Mach interferometer provided by the present invention;

[0040] Figure 2 This is a schematic top view of the optical path of a white-light Mach interferometer provided by the present invention;

[0041] Figure 3 This is a structural schematic diagram of an optical path adjustment mechanism in a white light Mach interferometer provided by the present invention;

[0042] Figure 4 This is a structural schematic diagram of a blade holder in a white light Mach interferometer provided by the present invention;

[0043] In the figure: 1. Structural component; 2. Projection component; 201. Light source; 202. First beam splitter prism; 203. Second beam splitter prism; 204. Third beam splitter prism; 205. Beam combining prism; 206. Reflector; 206a. Light angle adjustment member; 3. Optical path adjustment mechanism; 301. Fixing surface; 302. Adjustment surface; 303. Hand-tightened thread pair; 304. Dimming mirror; 305. Mounting hole; 306. Screw; 4. Schlieren observation component; 401. Blade holder; 401a. Adjustable blade; 401b. Adjustment screw; 401c. Through hole; 401d. Adjustment gap; 401e. Fastening bolt; 402. Observation camera; 5. Detection group mounting parts; 501. Experimental group frame; 502. Control group frame. DETAILED DESCRIPTION

[0044] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following description and claims. It should be noted that the drawings are greatly simplified and not to exact scale, and are intended solely to facilitate and clearly illustrate the embodiments of the present invention.

[0045] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention 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 cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0046] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0047] Example 1

[0048] This embodiment provides a white light Mach interferometer. Figures 1 to 4, comprising a structural component 1, the structural component 1 comprising an optical flat plate 101, a plurality of support frames 102 mounted on the optical flat plate 101, the support frames 102 being connected by cage rods 103, and a plurality of cage frames 104 being connected in series on the cage rods 103, the support frames 102 and the cage rods 103 jointly supporting the various components of the white light Mach interferometer; a projection component 2, the projection component 2 comprising a light source 201, a first beam splitter prism 202, a second beam splitter prism 203, a third beam splitter prism 204, and a beam combining prism 205, the light source 201 employs white light for interference, the second beam splitter prism 203 and the third beam splitter prism 204 respectively face the two directions of the light split by the first beam splitter prism 202, and the light is reflected by a reflector and converged to the beam combining prism 205; an optical path adjustment mechanism 3, the optical path adjustment mechanism The section mechanisms 3 are each arranged on one side of the second beam splitter prism 203 and the third beam splitter prism 204, for adjusting the optical path difference and enhancing the contrast of the interference pattern; the schlieren observation component 4 includes a blade holder 401 and an observation camera 402 arranged on one side of the blade holder 401, for observing interference fringes; the blade holder 401 is arranged between the beam combining prism 205 and the observation camera 402, and the blade holder 401 includes an adjustable blade 401a, which is perpendicular to the light beam emitted by the beam combining prism 205 and is located in the optical path and can cut off a part of the light beam; the detection group mounting part 5 includes an experimental group frame 501 arranged between the second beam splitter prism 203 and the beam combining prism 205, and a control group frame 502 arranged between the third beam splitter prism 204 and the beam combining prism 205.

[0049] The optical plate 101 is provided with a plurality of threaded holes 101a in an array, and the support frame 102 is fixedly mounted on the optical plate 101 by bolts; the first beam splitter prism 202, the second beam splitter prism 203, the third beam splitter prism 204, and the beam combining prism 205 are all mounted in a cage frame 104. The cage frame 104 is a regular cube structure with passages on its edges, and is detachably connected in series with the cage rods 103; the beam combining prism 205 reflects the light beam to the schlieren observation assembly 4 through a reflector 206; the reflector 206 includes a light angle adjustment member 206a provided on one side thereof.

[0050] The optical path adjustment mechanism 3 includes a fixed surface 301, an adjustment surface 302 arranged in parallel with the fixed surface 31, a hand-tightened thread pair 303 arranged on the surface of the fixed surface 301 and tightened diagonally, and a light-adjusting mirror 304 arranged on one side of the adjustment surface 302; the optical path adjustment mechanism 3 is connected in series with the cage rod 103 through the mounting hole 305, and the mounting hole 305 is tightened by the top block against the cage rod 103 through the screw 306 to fix the optical path adjustment mechanism 3 on the cage rod 103; the blade holder 401 also includes an adjustment screw 401b arranged on its two end surfaces, and the adjustment screw 401b is used to adjust The cross-sectional area of ​​the adjustable blade 401a is provided with through holes 401c for connecting the cage rod 103 in series at the four corners of the blade holder 401. The through holes 401c are connected to the adjustment gap 401d, and the gap is tightened by the fastening bolt 401e to fix the blade holder 401; the observation camera 402 uses a CCD camera, and the CCD target surface is used to capture the light interference signal to form interference fringes; the experimental group frame 501 is equipped with a cuvette containing the sample to be tested, and the control group frame 502 is equipped with a vacuum cuvette for control, and the installation angles and relative installation positions of the two cuvettes are consistent.

[0051] It should be noted that in theory, the two optical path lengths of the Mach interferometer are completely equal. However, due to assembly errors in the actual construction process and the accumulation of device processing errors, the overall error of the system is greater than the coherence length of white light (the coherence length of white light is generally around 3um). In addition, the Mach structure lacks an effective optical path difference adjustment structure, so we can hardly obtain white light interference fringes under the Mach structure. Mach interferometers are often used for high-precision measurement of the refractive index of transparent gases (hydrogen, helium, etc.) or transparent liquids (aviation kerosene, water, chemical reagents, etc.), and play an important role in the field of scientific research. The current Mach interferometer uses laser as the light source. The laser has a long coherence length and high measurement accuracy. Compared with lasers, wide-spectrum white light sources have a short coherence length. The measurement accuracy of the Mach interferometer using white light as the light source is much higher than that of lasers. Because of this, it is very unlikely to cause interference.

[0052] To this end, this embodiment optimizes the structure to inject light into the optical path adjustment mechanism 3 with adjustable optical path, and then reflects the light back to the original optical path through the dimming mirror 304, and continues to propagate without changing the original function of the structure. This method can make the Mach structure have an effective optical path difference adjustment mechanism, thereby realizing the application of white light Mach interferometer.

[0053] Preferably, the optical plate 101 is the base portion, on which the various components of the white light Mach interferometer can be mounted. The support frame 102 is detachably mounted on the optical plate 101 by bolts. The support frame 102 has through holes, through which the cage rods 103 are inserted to fix the cage frame 104, the optical path adjustment mechanism 3, and the blade holder 401. This type of support structure is not only adjustable but also very stable after being tightened.

[0054] Preferably, the first beam splitter prism 202, the second beam splitter prism 203, the third beam splitter prism 204, and the beam combining prism 205 are all installed in the cage 104, as well as the reflector 206, and the mirror surfaces of these are all oriented as shown in FIG. Figure 2 As shown, the light paths L1 and L2 represent the experimental group light beam and the control group light beam respectively.

[0055] In summary, the white light Mach interferometer of the present invention uses white light as a light source, overcomes the common speckle noise and phase jump problems in laser interferometers, and adds an optical path adjustment mechanism to overcome the white light defects. The optical path adjustment mechanism can adjust the angle by manually tightening the threaded pair. By manually adjusting the position of the optical path adjustment mechanism on the cage rod and locking it, the optical path can be flexibly adjusted during the experiment, so that the phases of the two lights can be kept consistent, ensuring the clarity and contrast of the interference pattern, thereby significantly improving the measurement accuracy and stability. In addition, the present invention also adds a Schlieren observation component, which is combined with a CCD camera to clearly capture interference fringes through Schlieren, facilitates subsequent data recording and analysis, and improves the convenience and effectiveness of experimental operations. At the same time, the Schlieren observation component has a variety of adjustment angles and cross-sectional area adjustment functions. The angle position can be flexibly changed during use to ensure that the camera can clearly record the interference fringes after Schlieren processing.

[0056] Example 2

[0057] The present invention provides a method for using a white light Mach interferometer. Figures 1 to 4 , including the following steps:

[0058] Step A: optical path calibration;

[0059] Step A1: The light source 201 emits a white light beam which is split into two beams by the first beam splitter prism 202, one of which is a transmitted light beam L1 and the other is a reflected light beam L2;

[0060] Step A2: The transmitted light beam L1 passes directly through the first beam-splitting prism 202 and is directed to the second beam-splitting prism 203. The second beam-splitting prism 203 first directs the light beam into the light-adjusting mirror 304 on one side of the second beam-splitting prism 203. By adjusting the position of the adjustment surface 302 relative to the cage rod 103 and fine-tuning the hand-screwed pair 303 to change the mirror angle, the light beam is reflected back to the second beam-splitting prism 203 via the adjustment surface 302. Finally, the light beam is reflected 90 degrees by the second beam-splitting prism 203 and enters the beam-combining prism 205.

[0061] Step A3: The reflected light beam L2 is reflected 90 degrees by the first beam-splitting prism 202 to the third beam-splitting prism 204. The third beam-splitting prism 204 first reflects the light into the dichroic mirror 304 on one side of the third beam-splitting prism 204. By adjusting the position of the adjustment surface 302 relative to the cage rod 103 and fine-tuning the hand-screwed pair 303 to change the mirror angle, the light is reflected back into the third beam-splitting prism 204 via the adjustment surface 302. Finally, the light is directly transmitted through the third beam-splitting prism 204 and enters the beam-combining prism 205. In this step, the optical path of the light beam in the third beam-splitting prism 204 must be equal to the optical path of the light beam in the second beam-splitting prism 203.

[0062] Step A4: Adjust the light angle adjustment member 206a so that the combined light beams are reflected by the reflector 206 onto the CCD target surface of the observation camera 402. The phases of the two combined light beams observed by the observation camera 402 should be in phase. After eliminating the influence of external environmental factors such as air, fine-tune the position and angle of the two dimming mirrors 304 and the reflector. If the phases are inconsistent, adjust the angle of the dimming mirror 304. If the image is unclear, adjust the position of the optical path adjustment mechanism 3 on the cage rod 103. Repeat steps A2 and A3 until the phases of the two combined light beams are consistent and the image is clear, and the optical path calibration is completed.

[0063] Step B: Schlieren observation component adjustment;

[0064] Step B1: Adjust the light path so that the light beam passes through the blade holder 401 correctly;

[0065] Step B2: Adjust the adjusting screw 401b to adjust the angle and position of the cutting blade to adjust the light-cutting area of ​​the adjustable blade 401a to optimize the contrast and clarity of the interference fringes;

[0066] Step B3: Capture the interference pattern through the CCD target surface of the observation camera 402, observe the pattern and fine-tune the adjustment screw 401b, the camera focal length and the position of the blade holder 401 at the same time until the camera can clearly record the interference fringes after Schlieren processing, and the Schlieren observation component adjustment is completed;

[0067] Step C: comparative experiment;

[0068] Step C1: The paths from light splitting to beam combining in Steps A and B are only on the experimental rack 501 and the control rack 502, with no test components installed. This step requires installing a cuvette containing the sample to be tested in the experimental rack 501, and a vacuum cuvette as a control in the control rack 502. The two cuvettes must be installed at the same angle and relative position to ensure that light can pass through the cuvettes and enter the beam combining prism 205.

[0069] Step C2: Observe the interference fringes of the two light beams of the experimental group and the control group through the observation camera 402. The phase information is expressed in the form of light intensity. The frequency changes with the wavelength of the light source as the period, and the change of the refractive index can be intuitively seen.

[0070] Step D: Data recording and analysis;

[0071] Step D1: Save the interference pattern image and record the experimental parameters (light source type, blade angle, camera settings, optical path adjustment mechanism position, etc.) for subsequent analysis. The use of the white light Mach interferometer is completed.

[0072] In summary, a white-light Mach interferometer and a method for using the same of the present invention first calibrate the optical path and the schlieren image, adjust the optical path to a position where an interference image can be clearly generated, calibrate the optical path by checking whether the phase of the CCD target surface light is consistent, and then use the optical phase interference generated between the optical paths of the experimental group frame and the control group frame, while introducing schlieren as an auxiliary means, so that the change in refractive index can be visually observed. This method can not only solve the problems of laser interference speckle and phase jump, making the detection more accurate, but also can be combined with schlieren technology, so that the change in refractive index can be visually observed, playing a role in auxiliary measurement.

[0073] The above description is only a description of the preferred embodiments of the present invention and does not limit the scope of the present invention. Any changes and modifications made by ordinary technicians in the field of the present invention based on the above disclosure shall fall within the scope of protection of the claims.

Claims

1. A white light Mach interferometer, characterized in that: include, A structural component (1), the structural component (1) comprising an optical plate (101), a plurality of support frames (102) mounted on the optical plate (101), the support frames (102) being connected by cage rods (103), and a plurality of cage frames (104) being connected in series on the cage rods (103), the support frames (102) and the cage rods (103) jointly supporting various components of a white light Mach interferometer; A projection assembly (2), the projection assembly (2) comprising a light source (201), a first beam splitting prism (202), a second beam splitting prism (203), a third beam splitting prism (204), and a beam combining prism (205), the light source (201) employing white light for interference, the second beam splitting prism (203) and the third beam splitting prism (204) respectively facing two directions after the first beam splitting prism (202) splits the light; the first beam splitting prism (202), the second beam splitting prism (203), the third beam splitting prism (204), and the beam combining prism (205) are all installed in a cage frame (104), the cage frame (104) being a regular cube structure with a passage provided on its edge, and being detachably connected in series with the cage rod (103); An optical path adjustment mechanism (3), each of which is arranged on one side of the second beam splitter prism (203) and the third beam splitter prism (204), and is used to adjust the optical path difference and enhance the contrast of the interference pattern; the optical path adjustment mechanism (3) comprises a fixing surface (301), an adjustment surface (302) arranged in parallel with the fixing surface (301), a hand-tightened thread pair (303) arranged on the surface of the fixing surface (301) and tightened diagonally, and a light-adjusting mirror (304) arranged on one side of the adjustment surface (302); the optical path adjustment mechanism (3) is connected in series with the cage rod (103) through the mounting hole (305), and the mounting hole (305) is tightened by a top block against the cage rod (103) through a screw (306), thereby fixing the optical path adjustment mechanism (3) on the cage rod (103); The light source (201) emits a white light beam which is divided into two beams through the first beam splitter prism (202), one of which is a transmitted light beam L1 and the other is a reflected light beam L2; the transmitted light beam L1 directly passes through the first beam splitter prism (202) and is directly incident on the second beam splitter prism (203); first, the second beam splitter prism (203) will directly incident the light into the dimming mirror (304) on one side of the second beam splitter prism (203); by adjusting the position of the adjustment surface (302) on the cage rod (103) and fine-tuning the hand-tightened thread pair (303) to change its mirror angle, the light is reflected back to the second beam splitter prism (203) through the adjustment surface (302), and finally reflected 90 degrees by the second beam splitter prism (203) into the beam combining prism (204). 5); the reflected light beam L2 is reflected 90 degrees by the first beam splitter prism (202) to the third beam splitter prism (204). First, the third beam splitter prism (204) reflects the light into the dimming mirror (304) on one side of the third beam splitter prism (204). By adjusting the position of the adjustment surface (302) on the cage rod (103) and fine-tuning the hand-screwed thread pair (303) to change its mirror angle, the light is reflected back to the third beam splitter prism (204) through the adjustment surface (302). Finally, the light is directly incident on the beam combining prism (205) through the third beam splitter prism (204), so that the path of the light beam in the third beam splitter prism (204) is equal to the optical path of the light beam in the second beam splitter prism (203); A Schlieren observation assembly (4) comprises a blade holder (401) and an observation camera (402) arranged on one side of the blade holder (401) and used for observing interference fringes; The blade holder (401) is arranged between the beam combining prism (205) and the observation camera (402), and the blade holder (401) comprises an adjustable blade (401a), wherein the adjustable blade (401a) is perpendicular to the light beam emitted by the beam combining prism (205) and is located in the light path and is capable of cutting off a portion of the light beam; The detection group mounting member (5) comprises an experimental group frame (501) arranged between the second beam splitter prism (203) and the beam combining prism (205), and a control group frame (502) arranged between the third beam splitter prism (204) and the beam combining prism (205); a cuvette containing a sample to be detected is installed in the experimental group frame (501), and a vacuum cuvette for comparison is installed in the control group frame (502), and the installation angles and relative installation positions of the two cuvettes are consistent.

2. A white light Mach interferometer as claimed in claim 1, characterized in that: A plurality of threaded holes (101a) are arranged in an array on the optical plate (101), and the support frame (102) is fixedly mounted on the optical plate (101) by means of bolts.

3. A white light Mach interferometer as claimed in claim 2, characterized in that: The beam combining prism (205) reflects the light beam to the schlieren observation assembly (4) via the reflector (206).

4. A white light Mach interferometer as claimed in claim 3, characterized in that: The reflector (206) comprises a light angle adjustment member (206a) arranged on one side thereof.

5. A white light Mach interferometer as claimed in claim 4, characterized in that: The blade holder (401) further comprises adjusting screws (401b) arranged on both end surfaces thereof, the adjusting screws (401b) being used to adjust the cross-sectional area of ​​the adjustable blade (401a), through holes (401c) for serially connecting the cage rods (103) are provided at the four corners of the blade holder (401), the through holes (401c) being connected to the adjustment gap (401d), and the gap is tightened by tightening bolts (401e) for fixing the blade holder (401).

6. A white light Mach interferometer as claimed in claim 5, characterized in that: The observation camera (402) uses a CCD camera, and the CCD target surface is used to capture light interference signals to form interference fringes.

7. A method for using the white light Mach interferometer according to claim 6, characterized in that: The steps include: Step A: optical path calibration; Step A1: The light source (201) emits a white light beam which is split into two beams by a first beam splitter prism (202), one of which is a transmitted light beam L1 and the other is a reflected light beam L2; Step A2: The transmitted light beam L1 directly passes through the first beam splitter prism (202) and is directly incident on the second beam splitter prism (203). First, the second beam splitter prism (203) will directly project the light into the light-adjusting mirror (304) on one side of the second beam splitter prism (203). By adjusting the position of the adjustment surface (302) on the cage rod (103) and fine-tuning the hand-screwed thread pair (303), the mirror angle thereof is changed, so that the light is reflected back to the second beam splitter prism (203) through the adjustment surface (302). Finally, the light is reflected 90 degrees through the second beam splitter prism (203) and is incident on the beam combining prism (205). Step A3: The reflected light beam L2 is reflected 90 degrees by the first beam splitter prism (202) to the third beam splitter prism (204). First, the third beam splitter prism (204) reflects the light into the dimming mirror (304) on one side of the third beam splitter prism (204). By adjusting the position of the adjustment surface (302) on the cage rod (103) and fine-tuning the hand-screwed thread pair (303), the mirror angle is changed so that the light is reflected back to the third beam splitter prism (204) through the adjustment surface (302). Finally, the light is directly incident on the beam combining prism (205) through the third beam splitter prism (204). This step requires that the path of the light beam in the third beam splitter prism (204) is equal to the optical path of the light beam in the second beam splitter prism (203); Step A4: Adjust the light angle adjustment member so that the combined light is reflected by the reflector (206) into the CCD target surface of the observation camera (402). The phases of the two combined light beams observed by the observation camera (402) should be in phase. After eliminating the influence of the external air environment, fine-tune the position angles of the two dimming mirrors (304) and the reflector. If the phases are inconsistent, adjust the angles of the dimming mirrors (304). If the image is not clear, adjust the position of the optical path adjustment mechanism (3) on the cage rod (103). Repeat steps A2 and A3 until the phases of the two combined light beams are consistent and the image is clear, and the optical path calibration is completed. Step B: Schlieren observation component adjustment; Step B1: Adjust the light path so that the light beam passes through the blade holder (401) correctly; Step B2: adjusting the adjusting screw (401b) to adjust the angle and position of the light-cutting blade to adjust the light-cutting area of ​​the adjustable blade (401a) to optimize the contrast and clarity of the interference fringes; Step B3: capturing the interference pattern through the CCD target surface of the observation camera (402), observing the pattern and fine-tuning the adjustment screw (401b), the camera focal length and the position of the blade holder (401) at the same time until the camera clearly records the interference fringes after the Schlieren processing, and the Schlieren observation component adjustment is completed; Step C: comparative experiment; Step C1: In the path from light splitting to beam combining in Step A and Step B, only the experimental group rack (501) and the control group rack (502) are present, and no detection components are installed. A cuvette containing a sample to be tested is installed in the experimental group rack (501), and a vacuum cuvette is installed in the control group rack (502) as a control. The installation angles and relative installation positions of the two cuvettes are consistent to ensure that light can pass through the cuvettes and enter the beam combining prism (205); Step C2: Observe the interference fringes of the two light beams of the experimental group and the control group through the observation camera (402), and the phase information is expressed in the form of light intensity. The frequency changes with the wavelength of the light source as the period, and the change of the refractive index can be seen intuitively; Step D: Data recording and analysis; Step D1: Save the interference pattern image and record the experimental parameters: light source type, blade angle, camera settings, and optical path adjustment mechanism position for subsequent analysis. The use of the white light Mach interferometer is now complete.

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