Michelson interferometer measurement method and Michelson interferometer

Abstract

The present application relates to a Michelson interferometer measurement method and a Michelson interferometer. The measurement method includes: emitting a first polarized light based on the optical properties of a first lens layer and a second lens layer; performing polarization modulation on the first reference polarized light and / or the first test polarized light so that the first reference polarized light and the first test polarized light have the same polarization state; emitting a second polarized light based on the optical properties of the first lens layer and the second lens layer; and performing polarization modulation on the second reference polarized light and / or the second test polarized light so that the second reference polarized light and the second test polarized light have the same polarization state. The present application employs a polarization modulation component to separately polarize the reference polarized light and the corresponding test polarized light, thereby ensuring that each reference polarized light and the corresponding test polarized light have the same polarization state, thereby enabling the morphology of each layer in the stacked structure to be measured.

Description

Technical Field

[0001] The present application relates to the field of optical measurement technology, and in particular to a measurement method of a Michelson interferometer and a Michelson interferometer. Background Art

[0002] With technological advancements and increasing user demands, electronic products are placing increasing demands on the quality of their optical systems. During actual use, the topography of optical components can impact their quality, so manufacturers typically measure the topography of these components using a Michelson interferometer. However, when testing stacked structures, traditional Michelson interferometers require first breaking the stack into multiple individual lens layers and then measuring each layer separately, which can easily lead to unnecessary losses in the stack. Summary of the Invention

[0003] Based on this, it is necessary to provide a Michelson interferometer measurement method and a Michelson interferometer to address the problem that when a traditional Michelson interferometer tests a stacked structure, it is necessary to split the stacked structure into multiple single-layer lenses and then measure each single-layer lens separately, which causes unnecessary losses to the stacked structure.

[0004] According to a first aspect of the present application, a measurement method for a Michelson interferometer is provided. The Michelson interferometer includes a light source, a reflector, a receiving sensor, and a non-polarizing beam splitter. The light source, the non-polarizing beam splitter, and the stacked structure are sequentially spaced apart along the z-direction, and the reflector, the non-polarizing beam splitter, and the receiving sensor are sequentially spaced apart along the y-direction, with the z-direction being perpendicular to the y-direction. The stacked structure includes a first lens layer and a second lens layer sequentially stacked along the z-direction.

[0005] The measuring method comprises:

[0006] emitting a first polarized light according to the optical properties of the first lens layer and the optical properties of the second lens layer;

[0007] Splitting the first polarized light into a first reference polarized light transmitted to the reflector and a first test polarized light transmitted to the first lens layer;

[0008] performing polarization modulation on the first reference polarized light and / or the first test polarized light so that the first reference polarized light reflected by the reflector to the receiving sensor has the same polarization state as the first test polarized light reflected by the first lens layer and transmitted to the receiving sensor;

[0009] emitting a second polarized light according to the optical properties of the first lens layer and the optical properties of the second lens layer;

[0010] Splitting the second polarized light into a second reference polarized light transmitted to the reflector and a second test polarized light transmitted to the second lens layer of the stacked structure;

[0011] The second reference polarized light and / or the second test polarized light are polarization modulated so that the second reference polarized light reflected by the reflector to the receiving sensor has the same polarization state as the second test polarized light reflected by the second mirror layer and transmitted to the receiving sensor.

[0012] In one embodiment, the step of emitting the first polarized light according to the optical properties of the first lens layer and the optical properties of the second lens layer specifically includes:

[0013] When the first lens layer includes a first quarter-wave plate and the second lens layer includes a reflective polarizer, x-direction polarized light or y-direction polarized light is emitted toward the non-polarizing beam splitter; wherein the x-direction, the y-direction, and the z-direction are arranged perpendicular to each other.

[0014] In one embodiment, the Michelson interferometer further includes a half wave plate and a second quarter wave plate;

[0015] The step of polarization-modulating the first reference polarized light and / or the first test polarized light so that the first reference polarized light reflected by the reflector to the receiving sensor has the same polarization state as the first test polarized light reflected by the first lens layer and transmitted to the receiving sensor specifically includes:

[0016] When the first polarized light is x-polarized light, using the second quarter-wave plate to convert the first reference polarized light and the first test polarized light into right-handed polarized light;

[0017] When the first polarized light is y-polarized light, the first reference polarized light and the first test polarized light are converted into right-handed polarized light by using the half wave plate and the second quarter wave plate.

[0018] In one embodiment, the Michelson interferometer further includes an x-axis linear polarizer and a y-axis linear polarizer, and the measurement method further includes:

[0019] using the x-direction linear polarizer to convert the first reference polarized light and the first test polarized light into x-direction polarized light; or

[0020] The first reference polarized light and the first test polarized light are converted into y-direction polarized light by using the y-direction linear polarizer.

[0021] In one embodiment, the measurement method includes:

[0022] The stacked structure is rotated about an axis parallel to the z-direction to enable x-direction polarized light to pass through the reflective polarizer.

[0023] In one embodiment, the step of emitting the second polarized light according to the optical properties of the first lens layer and the optical properties of the second lens layer specifically includes:

[0024] When the first lens layer includes a first quarter-wave plate and the second lens layer includes a reflective polarizer, x-direction polarized light or y-direction polarized light is emitted toward the non-polarizing beam splitter; wherein the x-direction, the y-direction, and the z-direction are arranged perpendicular to each other.

[0025] In one embodiment, the Michelson interferometer further includes a second quarter-wave plate, an x-direction linear polarizer, and a y-direction linear polarizer;

[0026] The step of polarization-modulating the second reference polarized light and / or the second test polarized light so that the second reference polarized light reflected by the reflector to the receiving sensor has the same polarization state as the second test polarized light reflected by the second lens layer and transmitted to the receiving sensor specifically includes:

[0027] When the second polarized light is x-polarized light, the second reference polarized light is converted into y-polarized light using the second quarter-wave plate, and the second test polarized light is converted into y-polarized light using the y-linear polarizer;

[0028] When the second polarized light is y-polarized light, the second reference polarized light is converted into x-polarized light using the second quarter-wave plate, and the second test polarized light is converted into x-polarized light using the x-linear polarizer.

[0029] In one embodiment, the measurement method includes:

[0030] The stacked structure is rotated around an axis parallel to the z-direction, so that the linearly polarized light reflected by the reflective polarizer can be converted into circularly polarized light after passing through the first quarter-wave plate.

[0031] According to a second aspect of the present application, a Michelson interferometer is further provided for testing the morphology of each layer structure in a stacked structure, the Michelson interferometer comprising:

[0032] a light source, arranged opposite to the stacked structure along the z-direction, and configured to emit polarized light toward the stacked structure along the z-direction;

[0033] a non-polarizing beam splitter, disposed between the light source and the stacked structure, the non-polarizing beam splitter being disposed at a 45-degree angle to the z-direction; the non-polarizing beam splitter being configured to split the polarized light emitted by the light source into a reference polarized light and a test polarized light, the test polarized light being configured to be transmitted to the stacked structure;

[0034] a reflector, arranged opposite to the non-polarizing beam splitter along the y-direction; the reference polarized light is used to transmit to the reflector;

[0035] a receiving sensor, disposed opposite to the non-polarizing beam splitter along the y-direction, and the receiving sensor is disposed on the other side of the non-polarizing beam splitter relative to the reflector; and

[0036] a polarization modulation component for performing polarization modulation on the reference polarized light and the test polarized light so that the reference polarized light reflected by the reflector to the receiving sensor has the same polarization state as the test polarized light reflected by the stacked structure and transmitted to the receiving sensor;

[0037] Wherein, the y direction is arranged perpendicular to the z direction.

[0038] In one embodiment, the stacked structure includes a first lens layer and a second lens layer stacked in sequence along the z-direction, the first lens layer includes a first quarter-wave plate, and the second lens layer includes a reflective polarizer, wherein:

[0039] The polarization modulation component includes a second quarter-wave plate disposed between the light source and the non-polarizing beam splitter, the second quarter-wave plate being used to convert x-polarized light into right-handed polarized light; or

[0040] The polarization modulation assembly includes a second quarter-wave plate disposed between the reflector and the non-polarizing beam splitter, the second quarter-wave plate being configured to convert y-polarized light into left-handed polarized light, or convert right-handed polarized light into x-polarized light, or convert x-polarized light into right-handed polarized light, or convert left-handed polarized light into y-polarized light;

[0041] The x-direction, the y-direction and the z-direction are arranged perpendicular to each other.

[0042] In one embodiment, the stacked structure includes a first lens layer and a second lens layer stacked in sequence along the z-direction, the first lens layer includes a first quarter-wave plate, and the second lens layer includes a reflective polarizer;

[0043] The polarization modulation component includes a half wave plate and a second quarter wave plate, which are arranged from the light source to the non-polarization beam splitter, and the half wave plate and the second quarter wave plate are sequentially spaced between the light source and the non-polarization beam splitter;

[0044] The half wave plate is used to convert the y-polarized light into the x-polarized light, and the quarter wave plate is used to convert the x-polarized light into the right-handed polarized light.

[0045] In one embodiment, the Michelson interferometer further includes a first optical element installed between the non-polarizing beam splitter and the receiving sensor, and the first optical element is configured as an x-axis linear polarizer or a y-axis linear polarizer.

[0046] In the technical solution of the present application, a Michelson interferometer emits a first polarized light and a second polarized light through a light source, and then uses a non-polarizing beam splitter to split the polarized light emitted by the light source into a test polarized light and a reference polarized light. For example, the non-polarizing beam splitter can split the first polarized light into a first reference polarized light and a first test polarized light, and can also split the second polarized light into a second reference polarized light and a second test polarized light. The reference polarized light will be reflected by the non-polarizing beam splitter toward the reflector, and then reflected by the reflector to the receiving sensor; the test polarized light will directly pass through the non-polarizing beam splitter and then toward the stacked structure, and after being reflected by the stacked structure, it will be emitted again toward the non-polarizing beam splitter, and finally reflected by the non-polarizing beam splitter to the receiving sensor.

[0047] The Michelson interferometer of the present application also features a polarization modulation assembly, comprising one or more optical elements. The polarization modulation assembly is capable of adjusting the polarization states of the test polarized light and the reference polarized light so that they have the same polarization state. When the test polarized light and the reference polarized light, each with the same polarization state, enter the receiving sensor, the Michelson interferometer generates two sets of interference fringes. By comparing the interference fringes generated by the test polarized light and the reference polarized light, the morphologies of the first and second lens layers in the stacked structure can be inferred. The present application utilizes the polarization modulation assembly to modulate the polarization states of the test polarized light and the reference polarized light, thereby aligning the polarization states of the test polarized light and the reference polarized light, thereby avoiding the influence and interference of optical elements in different layers of the stacked structure. This allows the Michelson interferometer to measure the morphology of each optical element in the stacked structure by adjusting the composition and mounting position of the polarization modulation assembly, thereby reducing the loss caused by the separation of the stacked structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 This is a schematic structural diagram of the first embodiment of the Michelson interferometer proposed in this application.

[0049] Figure 2This is a schematic structural diagram of the second embodiment of the Michelson interferometer proposed in this application.

[0050] Figure 3 This is a schematic structural diagram of the third embodiment of the Michelson interferometer proposed in this application.

[0051] Figure 4 for Figures 1 to 3 Front view of each layer in the laminate structure (after the laminate structure is disassembled).

[0052] Figure 5 This is a schematic structural diagram of the fourth embodiment of the Michelson interferometer proposed in this application.

[0053] Figure 6 for Figure 5 Front view of each layer in the laminate structure (after the laminate structure is disassembled).

[0054] Figure 7 FIG. 1 is a flow chart of a first embodiment of a Michelson interferometer measurement method proposed in this application.

[0055] Figure 8 FIG. 1 is a flow chart of a second embodiment of the Michelson interferometer measurement method proposed in this application.

[0056] Figure 9 This is a flow chart of the third embodiment of the Michelson interferometer measurement method proposed in this application.

[0057] Description of Figure Numbers:

[0058]

[0059] DETAILED DESCRIPTION

[0060] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0061] In the description of this application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply 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 a limitation on this application.

[0062] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly indicate the number of technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include such feature. In the description of this application, if the term "plurality" appears, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0063] In this application, unless otherwise specified or limited, the terms "mounted," "connected," "connected," "fixed," etc., should be interpreted broadly. For example, these terms may refer to fixed connections, removable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediary; and internal communication between two components or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0064] In this application, unless otherwise expressly specified or limited, if a first feature is described as being "above" or "below" a second feature, or similar descriptions, this may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is described as being "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is described as being "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0065] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only embodiment.

[0066] With technological advancements and increasing user demands, electronic products are placing increasing demands on the quality of their optical systems. During actual use, the topography of optical components can impact their quality, so manufacturers typically measure the topography of these components using a Michelson interferometer. However, when testing stacked structures, traditional Michelson interferometers require first breaking the stack into multiple individual lens layers and then measuring each layer separately, which can easily lead to unnecessary losses in the stack.

[0067] Through research, the researchers of this application discovered that a Michelson interferometer compares the differences in interference fringes generated by reference polarized light and test polarized light to infer the differences in the topography of the optical element under test and the reflector, thereby measuring the topography of the optical element under test. However, when a conventional Michelson interferometer is used to measure the topography of a stacked structure, the optical elements in different layers of the stack interfere with each other, resulting in different polarizations of light emitted by the optical element under test and the reflector, making it impossible to compare the interference fringes generated by the two.

[0068] In view of this, the present application proposes a Michelson interferometer, which aims to solve the problem that when testing a stacked structure, a traditional Michelson interferometer can only split the stacked structure into single layers and then measure them separately. Figures 1 to 6 Schematic diagram of the structure of an embodiment of the Michelson interferometer proposed in this application.

[0069] See also Figures 1 to 3 The Michelson interferometer proposed in this application is used to measure the morphology of each layer in a stacked structure 100. The Michelson interferometer includes a light source 1, a non-polarizing beam splitter 4, a reflector 2, a receiving sensor 3, and a polarization modulation component 5. The light source 1 is arranged relative to the stacked structure 100 along the z-direction and is configured to emit polarized light toward the stacked structure 100 along the z-direction.

[0070] The non-polarizing beam splitter 4 is disposed between the light source 1 and the stacked structure 100 , and is oriented at a 45-degree angle to the z-direction. The non-polarizing beam splitter 4 is configured to split the polarized light emitted by the light source 1 into a reference polarized light and a test polarized light, and the test polarized light is transmitted to the stacked structure 100 .

[0071] Reflector 2 is positioned opposite non-polarizing beam splitter 4 along the y-direction; reference polarized light is transmitted to reflector 2. Receiving sensor 3 is positioned opposite non-polarizing beam splitter 4 along the y-direction, on the other side of non-polarizing beam splitter 4 relative to reflector 2. Polarization modulation component 5 is used to modulate the polarization of reference polarized light and test polarized light, so that the reference polarized light reflected by reflector 2 to receiving sensor 3 has the same polarization state as the test polarized light reflected by stacked structure 100 and transmitted to receiving sensor 3. The y-direction is perpendicular to the z-direction.

[0072] In the present application, the y direction and the z direction are two relative directions, wherein the z direction can be set as the relative direction of the light source 1 and the stacked structure 100 , and the y direction can be the relative direction of the reflector 2 and the receiving sensor 3 .

[0073] In the technical solution of the present application, the Michelson interferometer emits a first polarized light 200 and a second polarized light 300 via a light source 1, and then the polarized light emitted by the light source 1 is split into a test polarized light and a reference polarized light via a non-polarizing beam splitter 4. For example, the non-polarizing beam splitter 4 can split the first polarized light 200 into a first reference polarized light 220 and a first test polarized light 210, and can also split the second polarized light 300 into a second reference polarized light 320 and a second test polarized light 310. The reference polarized light is reflected by the non-polarizing beam splitter 4 toward the reflector 2, and then reflected by the reflector 2 to the receiving sensor 3; the test polarized light directly passes through the non-polarizing beam splitter 4 and is emitted to the stacked structure 100. After being reflected by the stacked structure 100, it is emitted again to the non-polarizing beam splitter 4, and finally reflected by the non-polarizing beam splitter 4 to the receiving sensor 3.

[0074] The Michelson interferometer of the present application also includes a polarization modulation assembly 5, which includes one or more optical elements. Polarization modulation assembly 5 is capable of adjusting the polarization states of the test polarized light and the reference polarized light so that the polarization states of the test polarized light and the reference polarized light are the same. When the test polarized light and the reference polarized light, with the same polarization state, are incident on the receiving sensor 3, the Michelson interferometer generates two sets of interference fringes. By comparing the interference fringes generated by the test polarized light and the reference polarized light, the morphologies of the first lens layer 110 and the second lens layer 120 in the laminated structure 100 can be inferred.

[0075] The present application uses polarization modulation assembly 5 to polarize test polarized light and reference polarized light, ensuring that their polarization states are identical, thereby avoiding the influence and interference of optical elements in different layers of the stacked structure 100. This allows the Michelson interferometer to measure the topography of each layer of optical elements in the stacked structure 100 by adjusting the composition and installation position of the polarization modulation assembly 5, thereby reducing the loss caused by the disassembly of the stacked structure. In fact, by adjusting the composition and installation position of the polarization modulation assembly 5, the Michelson interferometer can also measure different stacked structures 100.

[0076] In the present application, the laminated structure 100 includes a first lens layer 110 and a second lens layer 120 stacked sequentially along the z-direction. The first lens layer 110 includes a first quarter-wave plate 110a, and the second lens layer 120 includes a reflective polarizer 120a. Of course, the laminated structure 100 may also have other structures.

[0077] See also Figures 1 to 4 In one embodiment of the present application, the polarization modulation component 5 includes a second quarter-wave plate 51 disposed between the light source 1 and the non-polarizing beam splitter 4, and the second quarter-wave plate 51 is used to convert the x-polarized light into right-handed polarized light.

[0078] In fact, when the angle between the fast axis F of the quarter wave plate and the polarization direction of the incident polarized light is +45°, the quarter wave plate will convert the incident polarized light into left-handed circularly polarized light; when the angle between the fast axis F of the quarter wave plate and the polarization direction of the polarized light is -45°, the quarter wave plate will convert the incident polarized light into right-handed circularly polarized light.

[0079] That is, in this embodiment, the fast axis F of the second quarter-wave plate 51 extends at a -45° angle to the x-direction. In this case, the light source 1 is selected as an x-polarized light source 1. After the second quarter-wave plate 51 converts the x-polarized light into right-handed polarized light, the non-polarizing beam splitter 4 splits the right-handed polarized light into two beams. One beam, as the test polarized light, enters the stacked structure 100, and the other beam, as the reference polarized light, enters the reflector 2 and is reflected by the reflector 2 to the receiving sensor 3. At this time, the first quarter-wave plate 110a in the stacked structure 100 reflects the right-handed polarized light and converts it into left-handed polarized light. This light is then reflected by the non-polarizing beam splitter 4 and converted back into right-handed polarized light, which is then incident on the receiving sensor 3. Similarly, the other right-handed polarized light is reflected by the non-polarizing beam splitter 4 and then emitted toward the reflector 2, where it is converted into left-handed polarized light. This left-handed polarized light is then reflected again by the reflector 2 and converted back into right-handed polarized light, which is finally incident on the receiving sensor 3. Therefore, the polarization direction of the test polarized light is the same as that of the reference polarized light, thereby completing the measurement of the first lens layer 110 in the stacked structure 100 .

[0080] See also Figure 5 and Figure 6 In another embodiment of the present application, the polarization modulation component 5 includes a second quarter-wave plate 51 arranged between the reflector 2 and the non-polarizing beam splitter 4, and the second quarter-wave plate 51 is used to convert the y-polarized light into left-handed polarized light, or convert the right-handed polarized light into x-polarized light, or convert the x-polarized light into right-handed polarized light, or convert the left-handed polarized light into y-polarized light.

[0081] As mentioned above, in this embodiment, the extension direction of the fast axis F of the second quarter-wave plate 51 forms an angle of +45° with the y-direction, that is, an angle of -45° with the x-direction. Therefore, it is possible to convert y-polarized light into left-handed polarized light, right-handed polarized light into x-direction polarized light, x-direction polarized light into right-handed polarized light, and left-handed polarized light into y-polarized light.

[0082] In fact, when the specific composition of the stacked structure 100 is different from that proposed in this application, it is only necessary to adjust the orientation of the second quarter-wave plate 51, or to use different polarization modulation components 5 for polarization modulation as needed, so that the morphology of each layer structure in the stacked structure 100 can also be measured.

[0083] In addition, the x-direction is another relative direction in this application. In fact, the x-direction is another direction perpendicular to the y-direction and the z-direction.

[0084] See also Figure 3 In some embodiments, the laminated structure 100 includes a first lens layer 110 and a second lens layer 120 stacked sequentially along the z-direction. The first lens layer 110 includes a first quarter-wave plate 110a, and the second lens layer 120 includes a reflective polarizer 120a. The polarization modulation component 5 includes a half-wave plate 52 and a second quarter-wave plate 51. The polarization modulation component 5 is directed from the light source 1 toward the non-polarizing beam splitter 4. The half-wave plate 52 and the second quarter-wave plate 51 are sequentially spaced apart and disposed between the light source 1 and the non-polarizing beam splitter 4. The half-wave plate 52 is used to convert y-polarized light into x-polarized light, and the quarter-wave plate is used to convert x-polarized light into right-handed polarized light.

[0085] Half-wave plate 52 shifts the angle of linearly polarized light by 90 degrees, converting y-polarized light into x-polarized light. The fast axis F of second quarter-wave plate 51 extends at -45° to the x-axis, converting x-polarized light into right-handed polarized light, thus enabling subsequent measurements.

[0086] See also Figure 2 and Figure 5In practical applications, after the test polarized light enters the stacked structure 100, other structures in the stacked structure 100 may reflect excess light, which, along with the test polarized light, is emitted toward the receiving sensor 3, interfering with the topography measurement. Therefore, in some embodiments, the Michelson interferometer further includes a first optical element 6 mounted between the non-polarizing beam splitter 4 and the receiving sensor 3. The first optical element 6 is configured as an x-axis linear polarizer 61 or a y-axis linear polarizer 62.

[0087] When a y-axis linear polarizer 62 is placed between the non-polarizing beam splitter 4 and the receiving sensor 3, only y-axis polarized light and the y-axis component of the circularly polarized light can enter the receiving sensor 3. When an x-axis linear polarizer 61 is placed between the non-polarizing beam splitter 4 and the receiving sensor 3, only x-axis polarized light and the x-axis component of the circularly polarized light can enter the receiving sensor 3, thereby preventing excess light from interfering with the topography measurement. In this application, the first optical element 6 can be adjusted and selected as needed. For example, it can be an x-axis linear polarizer 61, a y-axis linear polarizer 62, or even the first optical element 6 can be omitted.

[0088] Based on the above hardware conditions, this application also proposes a Michelson interferometer measurement method. Figures 7 to 9 This is a flow chart illustrating an embodiment of the Michelson interferometer measurement method proposed in this application. The Michelson interferometer includes a light source 1, a reflector 2, a receiving sensor 3, and a non-polarizing beam splitter 4. The light source 1, non-polarizing beam splitter 4, and stacked structure 100 are sequentially spaced along the z-direction. The reflector 2, non-polarizing beam splitter 4, and receiving sensor 3 are sequentially spaced along the y-direction, with the z-direction and the y-direction being perpendicular to each other. The stacked structure 100 includes a first lens layer 110 and a second lens layer 120 stacked sequentially along the z-direction.

[0089] See also Figure 1 and Figure 7 , measurement methods include:

[0090] S10: Emit first polarized light 200 based on the optical properties of the first lens layer 110 and the optical properties of the second lens layer 120. In practical applications, the Michelson interferometer may need to test the morphology of different laminated structures 100. Therefore, before beginning the test, it is necessary to select the type of light source 1 and emit the corresponding first polarized light 200 based on the specific structure of the laminated structure 100, that is, the optical properties of the first lens layer 110 and the optical properties of the second lens layer 120, to facilitate subsequent measurement of the first lens layer 110.

[0091] S20: Splitting the first polarized light 200 into a first reference polarized light 220 transmitted to the reflector 2 and a first test polarized light 210 transmitted to the first lens layer 110. The first polarized light 200 passes through the non-polarizing beam splitter 4, which reflects a portion of the first polarized light 200 toward the reflector 2, thereby forming the first reference polarized light 220. The other portion of the first polarized light 200 directly passes through the non-polarizing beam splitter 4 and is emitted to the stacked structure 100, thereby forming the first test polarized light 210. It should be noted that the non-polarizing beam splitter 4 splits the light according to its energy but converts the polarization state of the reflected light. Therefore, the polarization states of the first reference polarized light 220 and the first test polarized light 210 are different.

[0092] S30: Polarization modulate the first reference polarized light 220 and the first test polarized light 210 so that the first reference polarized light 220 reflected by the reflector 2 and transmitted to the receiving sensor 3 has the same polarization state as the first test polarized light 210 reflected by the first lens layer 110 and transmitted to the receiving sensor 3. Each optical element in the stacked structure 100 converts the first test polarized light 210, resulting in different polarizations between the first test polarized light 210 and the first reference polarized light 220, making it impossible to measure. Therefore, in the application, the Michelson interferometer uses the polarization modulation component 5 to polarize the first reference polarized light 220 and the first test polarized light 210 separately, so that the first reference polarized light 220 and the first test polarized light 210 have the same polarization state, thereby completing the measurement of the topography of the first lens layer 110 in the stacked structure 100.

[0093] S40: Emitting a second polarized light 300 based on the optical properties of the first lens layer 110 and the optical properties of the second lens layer 120. In practical applications, the Michelson interferometer may need to test the morphologies of different laminated structures 100. Therefore, before testing begins, it is necessary to select the type of light source 1 and emit the corresponding second polarized light 300 based on the specific structure of the laminated structure 100, namely, the optical properties of the first lens layer 110 and the second lens layer 120, to facilitate subsequent measurement of the second lens layer 120.

[0094] S50: Splitting the second polarized light 300 into a second reference polarized light 320 transmitted to the reflector 2 and a second test polarized light 310 transmitted to the second lens layer 120 of the stacked structure 100. The second polarized light 300 passes through the non-polarizing beam splitter 4, which reflects a portion of the second polarized light 300 toward the reflector 2, thereby forming the second reference polarized light 320. The other portion of the second polarized light 300 directly passes through the non-polarizing beam splitter 4 and is emitted to the stacked structure 100, thereby forming the second test polarized light 310. It should be noted that the non-polarizing beam splitter 4 splits the light according to its energy but converts the polarization state of the reflected light. Therefore, the second reference polarized light 320 and the second test polarized light 310 have different polarization states.

[0095] S60: Polarization modulate the second reference polarized light 320 and the second test polarized light 310 so that the second reference polarized light 320 reflected by the reflector 2 and transmitted to the receiving sensor 3 have the same polarization state as the second test polarized light 310 reflected by the second lens layer 120 and transmitted to the receiving sensor 3. Each optical element in the stacked structure 100 converts the second test polarized light 310, resulting in different polarizations between the second test polarized light 310 and the second reference polarized light 320, making it impossible to measure. Therefore, in the application, the Michelson interferometer uses the polarization modulation element 5 to polarize the second reference polarized light 320 and the second test polarized light 310 separately, so that the second reference polarized light 320 and the second test polarized light 310 have the same polarization state, thereby completing the measurement of the topography of the second lens layer 120 in the stacked structure 100.

[0096] In practical applications, the Michelson interferometer can sometimes adjust the polarization direction of the first test polarized light 210 to be consistent with the polarization direction of the first reference polarized light 220, or adjust the polarization direction of the first reference polarized light 220 to be consistent with the polarization direction of the first test polarized light 210, via the polarization modulation component 5. In other words, the Michelson interferometer does not need to modulate both the first test polarized light 210 and the first reference polarized light 220 simultaneously. Instead, it can modulate either the first test polarized light 210 or the first reference polarized light 220, depending on actual needs. Therefore, in the present application, step S30 has other implementations. Step S30 can also include polarization modulation of either the first reference polarized light 220 or the first test polarized light 210, so that the first reference polarized light 220 reflected by the reflector 2 and transmitted to the receiving sensor 3 has the same polarization state as the first test polarized light 210 reflected by the first lens layer 110 and transmitted to the receiving sensor 3.

[0097] Similarly, the Michelson interferometer can sometimes adjust the polarization direction of the second test polarized light 310 to be consistent with the polarization direction of the second reference polarized light 320, or adjust the polarization direction of the second reference polarized light 320 to be consistent with the polarization direction of the second test polarized light 310, through the polarization modulation component 5. Therefore, the Michelson interferometer does not need to modulate both the second test polarized light 310 and the second reference polarized light 320 simultaneously. Instead, it can modulate either the second test polarized light 310 or the second reference polarized light 320, depending on actual needs. Therefore, in the present application, step S30 has other implementations. Step S30 can also include polarization modulation of either the second reference polarized light 320 or the second test polarized light 310, so that the second reference polarized light 320 reflected by the reflector 2 and transmitted to the receiving sensor 3 has the same polarization state as the second test polarized light 310 reflected by the second lens layer 120 and transmitted to the receiving sensor 3.

[0098] In this application, the x-, y-, and z-directions are three relative directions. The z-direction is the direction of light emitted by light source 1, while x-polarized light is s-polarized light in the optical field, and y-polarized light is p-polarized light in the optical field. For ease of explanation, in this application, these are collectively referred to as x-polarized light and y-polarized light.

[0099] See also Figure 1 In some embodiments, step S10 specifically includes:

[0100] S11: When the first lens layer 110 includes a first quarter-wave plate 110a and the second lens layer 120 includes a reflective polarizer 120a, x-polarized light or y-polarized light is emitted toward the non-polarizing beam splitter 4. The x-, y-, and z-polarized light are arranged perpendicular to each other. When testing the topography of the first lens layer 110, i.e., the first quarter-wave plate 110a, the Michelson interferometer can use either an x-polarized light source 1 or a y-polarized light source 1. The Michelson interferometer can measure the topography of the first quarter-wave plate 110a using either light source 1, without being limited by the type of light source 1.

[0101] In this application, the first lens layer 110 is described as a first quarter-wave plate 110a, and the second lens layer 120 is described as a reflective polarizer 120a. In practice, the stacked structure 100 can also be an optical structure with more layers, and the first lens layer 110 and the second lens layer 120 can also be other optical structures. The Michelson interferometer only needs to adaptively adjust the polarization modulation component 5.

[0102] In some embodiments, the Michelson interferometer further includes a half wave plate 52 and a second quarter wave plate 51. Step S30 specifically includes:

[0103] S31: When the first polarized light 200 is x-polarized light, the first reference polarized light 220 and the first test polarized light 210 are converted into right-handed polarized light using the second quarter-wave plate 51. Figure 1 The fast axis F of the second quarter-wave plate 51 extends at -45° to the x-direction. At this time, when the light source 1 is selected as the x-polarized light source 1, the second quarter-wave plate 51 will convert the x-polarized light into right-handed polarized light. The non-polarizing beam splitter 4 will split the right-handed polarized light into two beams, one of which is incident on the stacked structure 100 as the first test polarized light 210, and the other is incident on the reflector 2 as the first reference polarized light 220. At this time, the first quarter-wave plate 110a in the stacked structure 100 will convert the first test polarized light 210 into left-handed polarized light through reflection. The left-handed polarized light will enter the receiving sensor 3 after being reflected by the non-polarizing beam splitter 4 and converted into right-handed polarized light. The first reference polarized light will be reflected by the non-polarizing beam splitter 4 and converted into left-handed polarized light and enter the reflector 2. The reflector 2 will convert the left-handed polarized light into right-handed polarized light through reflection and enter the receiving sensor 3. Therefore, in some embodiments, by placing a second quarter-wave plate 51 between the light source 1 and the non-polarizing beam splitter 4, the Michelson interferometer can ensure that the polarization directions of the first test polarized light 210 and the first reference polarized light 220 are the same, thereby enabling measurement of the first lens layer 110 in the stacked structure 100. It should be noted that the quarter-wave plate itself has a certain reflectivity, which enables the quarter-wave plate to perform topography measurement.

[0104] S32: When the first polarized light 200 is y-polarized light, the first reference polarized light 220 and the first test polarized light 210 are converted into right-handed polarized light using the half-wave plate 52 and the second quarter-wave plate 51. Figure 3In practice, the half-wave plate 52 and the second quarter-wave plate 51 can be sequentially spaced between the light source 1 and the non-polarizing beam splitter 4. At this point, the first polarized light 200 will first enter the half-wave plate 52, where it will be converted from y-polarized light to x-polarized light. The light will then enter the second quarter-wave plate 51, which will convert the x-polarized light into right-handed polarized light. The right-handed polarized light will then be split into two beams by the non-polarizing beam splitter 4. One beam will serve as the first test polarized light 210 and enter the stacked structure 100, while the other will serve as the first reference polarized light 220 and enter the reflector 2. The subsequent light conversion is the same as step S31. The first quarter-wave plate 110a in the stacked structure 100 will convert the first test polarized light 210 into left-handed polarized light through reflection. The left-handed polarized light will then enter the receiving sensor 3 after being reflected by the non-polarizing beam splitter 4 and converted into right-handed polarized light. The first reference polarized light is reflected by the non-polarizing beam splitter 4 and converted into left-handed polarized light, and then enters the reflector 2 . The reflector 2 then converts the left-handed polarized light into right-handed polarized light through reflection, and then enters the receiving sensor.

[0105] In other words, the Michelson interferometer can be used to measure the topography of the first lens layer 110 using either the x-polarized light source 1 or the y-polarized light source 1; the measurement requires different optical elements for polarization modulation. In practice, when the composition of the stacked structure 100 varies, the Michelson interferometer can be adjusted to utilize different optical elements for polarization modulation to achieve similar measurements.

[0106] In practical applications, after the test polarized light enters the stacked structure 100, other structures in the stacked structure 100 may reflect excess light, which is emitted toward the receiving sensor 3 together with the test polarized light, interfering with the topography measurement. Therefore, in some embodiments, the Michelson interferometer further includes an x-axis linear polarizer 61 and a y-axis linear polarizer 62. Figure 2 The measurement method further includes step S33:

[0107] The first reference polarized light 220 and the first test polarized light 210 are converted into x-polarized light by the x-linear polarizer 61 .

[0108] The x-polarizer can block all light except for x-polarized light, thereby preventing other light from interfering with topography measurement. In practice, when the light incident on the x-polarizer is circularly polarized light, the x-polarizer blocks the y-polarization component of the circularly polarized light. For example, in this embodiment, the first reference polarized light 220 and the first test polarized light 210 are both right-handed polarized light. When incident on the x-linear polarizer 61, the y-polarization component of the first reference polarized light 220 and the first test polarized light 210 is blocked, and only the x-polarization component is allowed to enter the receiving sensor 3, thereby converting the first reference polarized light 220 and the first test polarized light 210 into x-polarized light.

[0109] Also, see Figure 2 The measurement method may further include step S34:

[0110] The first reference polarized light 220 and the first test polarized light 210 are converted into y-polarized light by the y-linear polarizer 62 .

[0111] When the light incident on the y-direction linear polarizer 62 is circularly polarized light, the y-direction polarizer blocks the x-direction polarization component of the circularly polarized light. For example, in this embodiment, the first reference polarized light 220 and the first test polarized light 210 are both right-handed polarized light. When incident on the y-direction linear polarizer 62, the x-direction polarization component of the first reference polarized light 220 and the first test polarized light 210 is blocked, and only the y-direction polarization component is allowed to enter the receiving sensor 3, thereby converting the first reference polarized light 220 and the first test polarized light 210 into y-direction polarized light.

[0112] In some embodiments, see Figure 4 The measurement method further includes step S35:

[0113] The stacked structure 100 is rotated about an axis parallel to the z-direction so that x-polarized light can pass through the reflective polarizer 120a.

[0114] In practical applications, the laminated structure 100 comprises multiple layers of sequentially stacked optical elements. Therefore, rotating the laminated structure 100 can utilize the varying characteristics of the optical elements to a certain extent. Rotating the laminated structure 100 about an axis parallel to the z-direction allows the transmission axis T of the reflective polarizer 120a in the laminated structure 100 to be aligned with the x-direction. In this case, x-polarized light incident on the reflective polarizer 120a passes directly through it, preventing additional light from being reflected by the reflective polarizer 120a. Consequently, only the first test polarized light 210 and the first reference polarized light 220 enter the receiving sensor 3. This prevents interference with the Michelson interferometer's measurement of the first lens layer 110, facilitating smoother Michelson interferometer measurements.

[0115] In some embodiments, step S40 specifically includes:

[0116] When the first lens layer 110 includes a first quarter-wave plate 110a and the second lens layer 120 includes a reflective polarizer 120a, x-polarized light or y-polarized light is emitted toward the non-polarizing beam splitter 4. The x-, y-, and z-polarized light are arranged perpendicular to each other. When testing the topography of the second lens layer 120, i.e., the reflective polarizer 120a, the Michelson interferometer can use either an x-polarized light source 1 or a y-polarized light source 1. The Michelson interferometer can measure the topography of the reflective polarizer 120a using either light source 1, without being limited by the type of light source 1.

[0117] In some embodiments, the Michelson interferometer further includes a second quarter wave plate 51, an x-axis linear polarizer 61, and a y-axis linear polarizer 62. Figure 5 and Figure 9 , step S60 specifically includes:

[0118] S61: When the second polarized light 300 is x-polarized light, the second reference polarized light 320 is converted into y-polarized light using the second quarter-wave plate 51, and the second test polarized light 310 is converted into y-polarized light using the y-linear polarizer 62. In practical applications, the second quarter-wave plate 51 can be positioned between the reflector 2 and the non-polarizing beam splitter 4, and the y-linear polarizer 62 can be positioned between the non-polarizing beam splitter 4 and the receiving sensor 3. At this point, for the second reference polarized light 320, the second quarter-wave plate 51 can convert the x-polarized light incident on the reflector 2 into right-handed polarized light. The right-handed polarized light then incidents on the reflector 2 and is reflected and converted into left-handed polarized light. The left-handed polarized light then passes through the second quarter-wave plate 51 and is converted into y-polarized light.

[0119] At this point, the x-polarized light of the second test polarized light 310 remains unchanged after entering the first quarter-wave plate 110a. However, the x-polarized light continues to enter the reflective polarizer 120a, where it is reflected by the reflective polarizer 120a and converted into linearly polarized light with a polarization direction at a 45° angle to the y-direction. This linearly polarized light then passes through the first quarter-wave plate 110a again, where it is converted into right-handed polarized light. This right-handed polarized light is then reflected by the non-polarizing beam splitter 4 and converted into left-handed polarized light. The left-handed polarized light finally passes through the y-linear polarizer 62 and is converted into y-polarized light. Therefore, the Michelson interferometer, through the second quarter-wave plate 51 and the y-linear polarizer 62, can adjust both the second reference polarized light 320 and the second test polarized light 310 to y-polarized light, thereby completing the measurement of the reflective polarizer 120a.

[0120] S62: When the second polarized light 300 is y-polarized light, the second reference polarized light 320 is converted into x-polarized light using the second quarter-wave plate 51, and the second test polarized light 310 is converted into x-polarized light using the x-linear polarizer 61. Similarly, in actual applications, the second quarter-wave plate 51 can be positioned between the reflector 2 and the non-polarizing beam splitter 4, and the x-linear polarizer 61 can be positioned between the non-polarizing beam splitter 4 and the receiving sensor 3. At this point, for the second reference polarized light 320, the second quarter-wave plate 51 can convert the y-polarized light incident on the reflector 2 into left-handed polarized light. The left-handed polarized light then incidents on the reflector 2 and is converted into right-handed polarized light after reflection. The right-handed polarized light then passes through the second quarter-wave plate 51 again and is converted into x-polarized light.

[0121] At this point, the y-polarized light of the second test polarized light 310 remains unchanged after entering the first quarter-wave plate 110a. Instead, the y-polarized light continues to travel toward the reflective polarizer 120a, where it is reflected and converted into linearly polarized light with a polarization direction at a 45° angle to the x-direction. This linearly polarized light then passes through the first quarter-wave plate 110a again, where it is converted into left-handed polarized light. This left-handed polarized light is then reflected by the non-polarizing beam splitter 4 and converted into right-handed polarized light. The right-handed polarized light finally passes through the x-linear polarizer 61 and is converted into x-polarized light. Therefore, the Michelson interferometer can similarly adjust the second reference polarized light 320 and the second test polarized light 310 to x-polarized light through the second quarter-wave plate 51 and the x-linear polarizer 61, thereby completing the measurement of the reflective polarizer 120a.

[0122] In some embodiments, see Figure 6 The measurement method further includes step S63:

[0123] The stacked structure 100 is rotated around an axis parallel to the z-direction, so that the linearly polarized light reflected by the reflective polarizer 120 a can be converted into circularly polarized light after passing through the first quarter-wave plate 110 a .

[0124] In practical applications, stacked structure 100 comprises multiple layers of sequentially stacked optical elements. Therefore, rotating stacked structure 100 can utilize the varying characteristics of the optical elements to a certain extent. Rotating stacked structure 100 about an axis parallel to the z-direction aligns the fast axis F of first quarter-wave plate 110a in stacked structure 100 with the y-direction. In this case, the reflection axis R of reflective polarizer 120a forms a 45-degree angle with the y-direction.

[0125] At this time, when the y-polarized light enters the first quarter-wave plate 110a, it will not change. The y-polarized light will continue to enter the reflective polarizer 120a and be reflected by the reflective polarizer 120a and converted into linear polarized light with a polarization direction at a 45° angle to the x-direction. After this linear polarized light passes through the first quarter-wave plate 110a again, it will be converted into left-handed polarized light, thereby making the subsequent polarization modulation of the Michelson interferometer smoother.

[0126] In addition, when the x-polarized light enters the first quarter-wave plate 110a, it will not change. Instead, the x-polarized light will continue to enter the reflective polarizer 120a and be reflected by the reflective polarizer 120a to be converted into linearly polarized light with a polarization direction at a 45° angle to the y-direction. After this linearly polarized light passes through the first quarter-wave plate 110a again, it will be converted into right-handed polarized light, thereby making the subsequent polarization modulation of the Michelson interferometer smoother.

[0127] It should be noted that the composition of the stacked structure 100 itself must be considered when designing and adjusting the optical path using this method. While this application illustrates a stacked structure 100 comprising a first quarter-wave plate 110a as the first lens layer 110 and a reflective polarizer 120a as the second lens layer 120, this does not mean that this application is limited to measuring this stacked structure 100. The Michelson interferometer and Michelson interferometer measurement method proposed in this application can be applied to various stacked structures 100 after adaptive adjustments.

[0128] In practice, the laminated structure 100 proposed in this application may also include a third lens layer 130, which is actually a linear polarizer 130a. In practical applications, linear polarizer 130a does not reflect light, but only absorbs and transmits it. Therefore, this does not interfere with the optical system or topography measurement. Since topography measurement is not required in practical applications, linear polarizer 130a is not mentioned in this application, but is identified in the accompanying drawings.

[0129] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0130] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A Michelson interferometer measurement method, characterized in that: The Michelson interferometer includes a light source, a reflector, a receiving sensor, and a non-polarizing beam splitter; the light source, the non-polarizing beam splitter, and the stacked structure are sequentially spaced along the z-direction, the reflector, the non-polarizing beam splitter, and the receiving sensor are sequentially spaced along the y-direction, and the z-direction is perpendicular to the y-direction; the stacked structure includes a first lens layer and a second lens layer sequentially stacked along the z-direction; The measuring method comprises: emitting a first polarized light according to the optical properties of the first lens layer and the optical properties of the second lens layer; Splitting the first polarized light into a first reference polarized light transmitted to the reflector and a first test polarized light transmitted to the first lens layer; performing polarization modulation on the first reference polarized light and / or the first test polarized light so that the first reference polarized light reflected by the reflector to the receiving sensor has the same polarization state as the first test polarized light reflected by the first lens layer and transmitted to the receiving sensor; emitting a second polarized light according to the optical properties of the first lens layer and the optical properties of the second lens layer; Splitting the second polarized light into a second reference polarized light transmitted to the reflector and a second test polarized light transmitted to the second lens layer of the stacked structure; The second reference polarized light and / or the second test polarized light are polarization modulated so that the second reference polarized light reflected by the reflector to the receiving sensor has the same polarization state as the second test polarized light reflected by the second mirror layer and transmitted to the receiving sensor.

2. The Michelson interferometer measurement method according to claim 1, wherein: The step of emitting the first polarized light according to the optical properties of the first lens layer and the optical properties of the second lens layer specifically includes: When the first lens layer includes a first quarter-wave plate and the second lens layer includes a reflective polarizer, x-direction polarized light or y-direction polarized light is emitted toward the non-polarizing beam splitter; wherein the x-direction, the y-direction, and the z-direction are arranged perpendicular to each other.

3. The Michelson interferometer measurement method according to claim 2, wherein: The Michelson interferometer further includes a half wave plate and a second quarter wave plate; The step of polarization-modulating the first reference polarized light and / or the first test polarized light so that the first reference polarized light reflected by the reflector to the receiving sensor has the same polarization state as the first test polarized light reflected by the first lens layer and transmitted to the receiving sensor specifically includes: When the first polarized light is x-polarized light, using the second quarter-wave plate to convert the first reference polarized light and the first test polarized light into right-handed polarized light; When the first polarized light is y-polarized light, the first reference polarized light and the first test polarized light are converted into right-handed polarized light by using the half wave plate and the second quarter wave plate.

4. The Michelson interferometer measurement method according to claim 3, wherein: The Michelson interferometer further includes an x-axis linear polarizer and a y-axis linear polarizer, and the measurement method further includes: using the x-direction linear polarizer to convert the first reference polarized light and the first test polarized light into x-direction polarized light; or The first reference polarized light and the first test polarized light are converted into y-direction polarized light by using the y-direction linear polarizer.

5. The Michelson interferometer measurement method according to any one of claims 2 to 4, characterized in that: The measuring method comprises: The stacked structure is rotated about an axis parallel to the z-direction to enable x-direction polarized light to pass through the reflective polarizer.

6. The Michelson interferometer measurement method according to claim 1, wherein: The step of emitting the second polarized light according to the optical properties of the first lens layer and the optical properties of the second lens layer specifically includes: When the first lens layer includes a first quarter-wave plate and the second lens layer includes a reflective polarizer, x-direction polarized light or y-direction polarized light is emitted toward the non-polarizing beam splitter; wherein the x-direction, the y-direction, and the z-direction are arranged perpendicular to each other.

7. The Michelson interferometer measurement method according to claim 6, characterized in that: The Michelson interferometer further includes a second quarter-wave plate, an x-direction linear polarizer, and a y-direction linear polarizer; The step of polarization-modulating the second reference polarized light and / or the second test polarized light so that the second reference polarized light reflected by the reflector to the receiving sensor has the same polarization state as the second test polarized light reflected by the second lens layer and transmitted to the receiving sensor specifically includes: When the second polarized light is x-polarized light, the second reference polarized light is converted into y-polarized light using the second quarter-wave plate, and the second test polarized light is converted into y-polarized light using the y-linear polarizer; When the second polarized light is y-polarized light, the second reference polarized light is converted into x-polarized light using the second quarter-wave plate, and the second test polarized light is converted into x-polarized light using the x-linear polarizer.

8. The Michelson interferometer measurement method according to any one of claims 6 or 7, characterized in that: The measuring method comprises: The stacked structure is rotated around an axis parallel to the z-direction, so that the linearly polarized light reflected by the reflective polarizer can be converted into circularly polarized light after passing through the first quarter-wave plate.

9. A Michelson interferometer for measuring the morphology of each layer in a stacked structure, characterized in that: The Michelson interferometer comprises: a light source, arranged opposite to the stacked structure along the z-direction, and configured to emit polarized light toward the stacked structure along the z-direction; a non-polarizing beam splitter, disposed between the light source and the stacked structure, the non-polarizing beam splitter being disposed at a 45-degree angle to the z-direction; the non-polarizing beam splitter being configured to split the polarized light emitted by the light source into a reference polarized light and a test polarized light, the test polarized light being configured to be transmitted to the stacked structure; a reflector, arranged opposite to the non-polarizing beam splitter along the y-direction; the reference polarized light is used to transmit to the reflector; a receiving sensor, disposed opposite to the non-polarizing beam splitter along the y-direction, and the receiving sensor is disposed on the other side of the non-polarizing beam splitter relative to the reflector; and a polarization modulation component for performing polarization modulation on the reference polarized light and the test polarized light so that the reference polarized light reflected by the reflector to the receiving sensor has the same polarization state as the test polarized light reflected by the stacked structure and transmitted to the receiving sensor; Wherein, the y direction is arranged perpendicular to the z direction.

10. The Michelson interferometer according to claim 9, characterized in that The stacked structure comprises a first lens layer and a second lens layer sequentially stacked along the z-direction, the first lens layer comprises a first quarter-wave plate, and the second lens layer comprises a reflective polarizer, wherein: The polarization modulation component includes a second quarter-wave plate disposed between the light source and the non-polarizing beam splitter, the second quarter-wave plate being used to convert x-polarized light into right-handed polarized light; or The polarization modulation assembly includes a second quarter-wave plate disposed between the reflector and the non-polarizing beam splitter, the second quarter-wave plate being configured to convert y-polarized light into left-handed polarized light, or convert right-handed polarized light into x-polarized light, or convert x-polarized light into right-handed polarized light, or convert left-handed polarized light into y-polarized light; The x-direction, the y-direction and the z-direction are arranged perpendicular to each other.

11. The Michelson interferometer according to claim 9, wherein The stacked structure includes a first lens layer and a second lens layer sequentially stacked along the z-direction, the first lens layer includes a first quarter-wave plate, and the second lens layer includes a reflective polarizer; The polarization modulation component includes a half wave plate and a second quarter wave plate, which are arranged from the light source to the non-polarization beam splitter, and the half wave plate and the second quarter wave plate are sequentially spaced between the light source and the non-polarization beam splitter; The half wave plate is used to convert the y-polarized light into the x-polarized light, and the quarter wave plate is used to convert the x-polarized light into the right-handed polarized light.

12. The Michelson interferometer according to claim 9, wherein The device further comprises a first optical element installed between the non-polarization beam splitter and the receiving sensor, wherein the first optical element is configured as an x-direction linear polarizer or a y-direction linear polarizer.

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