Phase detection device using a phase transition method with geometric phase optical elements

Abstract

A phase-transition type phase detection device using geometric phase optical elements is disclosed. According to one embodiment of this invention, the phase detection device includes an optical mask that causes a phase transition between object light and reference light having different circular polarizations generated by an interferometer, wherein the optical mask includes an optical array containing geometric phase optical pixels that phase-delay the object light and the reference light by twice a predetermined optical axis rotation angle, and a circularly polarized beam splitter configured to transmit a portion of the circularly polarized components that have passed through the optical array.

Description

Technical Field

[0001] This embodiment relates to a phase detection device that detects the optical characteristics of object light in a phase transition manner using a geometric phase optical element.

Background Art

[0002] The content described in this part merely provides background information for this embodiment and does not constitute the prior art.

[0003] Optical inspection technology has been evolving from conventional 2D shape inspection to 3D shape inspection. Various technical attempts are being made to detect not only the intensity of light reflected from an object but also its phase and polarization characteristics. Among them, the Phase Shifting Interferometry method is utilized as a basic method for measuring 3D shapes with a simple optical system configuration and calculation algorithm.

[0004] Conventional phase transition methods use elements such as PZT (Piezo - electric Transducer) or LCVR (Liquid Crystal Variable Retarder) to detect the intensity and phase of object light reflected from the object surface. At this time, conventional phase transition methods capture a plurality of phase - shifted interference fringes by sequentially adjusting the phase of the reference light reflected from a reference mirror, and detect the aforementioned information using the interference fringes.

[0005] However, since conventional phase transition methods must obtain phase - shifted interference fringes through multiple shootings associated with the sequential adjustment of PZT or LCVR, there are fine time intervals in the process of obtaining the phase - shifted interference fringes. If irregular vibrations flow in from the environment during such time intervals, there is a problem that the phase detection performance of the conventional phase transition method deteriorates. However, in general industrial sites where mass production is actually carried out, various irregular vibrations always exist, so it is difficult to expect high phase detection performance from the conventional phase transition method in industrial sites.

[0006] As a method to avoid errors caused by vibration intrusion, a method of simultaneously capturing multiple phase transition interference fringes using multiple cameras is being studied. However, this method requires precise matching of the pixels of each camera corresponding to the same position on the object, thus necessitating additional equipment and work for matching. Furthermore, this method has the disadvantage of requiring additional space for arranging multiple cameras, making it difficult to realize a compact optical system, and the use of multiple expensive cameras results in high costs for the inspection equipment.

[0007] Therefore, there is a need to develop a new phase detection device that overcomes the disadvantage of conventional phase transition methods, which are vulnerable to vibrations caused by time-series imaging, and that does not require the use of multiple cameras, and includes a simple and inexpensive optical system. [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] One embodiment of the present invention aims to provide a phase detection device that has a simple structure using a geometric phase optical element, is resistant to external vibrations, and can detect the optical properties of object light. [Means for solving the problem]

[0009] According to one aspect of this embodiment, a phase detection device is provided that includes an optical mask for phase transitioning object light and reference light having different circular polarizations generated by an interferometer, wherein the optical mask includes an optical array containing geometric phase optical pixels that phase delay the object light and the reference light by twice a predetermined optical axis rotation angle, and a circularly polarized beam splitter configured to transmit a portion of the circularly polarized components that have passed through the optical array.

[0010] According to one aspect of this embodiment, the interferometer is characterized by including a light source that provides false interference light and a light source beam splitter that splits the light into object light and reference light.

[0011] According to one aspect of this embodiment, the circularly polarized beam splitter is characterized in that an anisotropic material or anisotropic structure is formed in a helical structure.

[0012] According to one aspect of this embodiment, the circularly polarized beam splitter is characterized by reflecting circularly polarized light rotating in the same direction as the helical structure and transmitting circularly polarized light rotating in the opposite direction.

[0013] According to one aspect of this embodiment, the phase detection device further includes a detection unit that detects interference fringes formed by object light and reference light transmitted through the circularly polarized beam splitter.

[0014] According to one aspect of this embodiment, the detection unit is characterized by acquiring a plurality of phase transition interference fringe images.

[0015] According to one aspect of this embodiment, the optical array is characterized in that, when light of one polarization is incident on it, it emits a polarization component identical to the incident light and an opposite polarization component that is phase-delayed by twice the optical axis rotation angle.

[0016] According to one aspect of this embodiment, the optical pixels are characterized in that object light from the same point is incident between a plurality of adjacent optical pixels.

[0017] According to one aspect of this embodiment, each adjacent optical pixel is characterized by having a different optical axis rotation angle from one another.

[0018] According to one aspect of this embodiment, the optical pixels are characterized in that object light from the same point is incident between at least three or more adjacent optical pixels.

[0019] According to one aspect of the present embodiment, in a method for a phase detection device to detect the phase of object light, a detection process of detecting interference fringes of the object light and reference light that are transmitted through an optical mask and detected by a detection unit, and a process of obtaining a plurality of interference fringe images by grouping the interference fringes detected in the detection process according to the optical axis rotation angle of geometric phase optical pixels, and a detection process of detecting the optical characteristics of the object light using the plurality of interference fringe images obtained in the obtaining process are included. A phase detection method is provided, characterized in that it includes these processes.

[0020] According to one aspect of the present embodiment, the optical mask includes an optical array including geometric phase optical pixels that delay the object light and the reference light by twice a predetermined optical axis rotation angle, and a circular polarization beam splitter configured to transmit a part of the circular polarization components among the circular polarization components transmitted through the optical array.

Effect of the Invention

[0021] As described above, according to one aspect of the present embodiment, there is an advantage that a simple structure can be used with a geometric phase optical element and the optical characteristics of object light can be detected.

[0022] Also, according to one aspect of the present embodiment, it is possible to obtain a plurality of phase transition interference fringe images even with one shot, and it has an advantage of being resistant to external vibrations.

Brief Description of the Drawings

[0023] [Figure 1] It is a diagram showing the configuration of a phase detection system according to an embodiment of the present invention. [Figure 2] It is a diagram showing the configuration of a phase detection device according to an embodiment of the present invention. [Figure 3] It is a diagram showing the configuration of an interferometer according to an embodiment of the present invention. [Figure 4] It is a diagram showing the configuration of an optical mask according to an embodiment of the present invention. [Figure 5] It is a diagram explaining the optical characteristics of an optical array according to an embodiment of the present invention. [Figure 6A] This figure shows the material properties of the material constituting an optical array according to one embodiment of the present invention. [Figure 6B] This figure shows the material properties of the material constituting an optical array according to one embodiment of the present invention. [Figure 7] This figure shows the structure of an optical array according to one embodiment of the present invention. [Figure 8] This figure shows the structure and chiral volume grating characteristics of a circularly polarized beam splitter according to one embodiment of the present invention. [Figure 9] This figure illustrates the optical characteristics of a circularly polarized beam splitter according to one embodiment of the present invention. [Figure 10] This figure illustrates the optical properties of an optical mask according to one embodiment of the present invention. [Figure 11] This figure illustrates the detection process of the optical characteristics of a phase detection device according to one embodiment of the present invention. [Figure 12A] This figure shows the pixel structure of phase-transitioned interference fringes detected by a detection unit according to one embodiment of the present invention. [Figure 12B] This figure shows the pixel structure of phase-transitioned interference fringes detected by a detection unit according to one embodiment of the present invention. [Figure 13] This flowchart shows a method by which a phase detection device according to one embodiment of the present invention detects the optical characteristics of a target object. [Modes for carrying out the invention]

[0024] While the present invention can be modified in various ways and have many embodiments, specific embodiments are illustrated and described in detail in the drawings. However, it should be understood that this does not limit the present invention to specific embodiments, but rather includes all modifications, equivalents, or substitutions that fall within the spirit and technical scope of the present invention. In describing each drawing, similar reference numerals are used for similar components.

[0025] Terms such as First, Second, A, B, etc., can be used to describe a variety of components, but the components should not be limited by such terms. The terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the First component may be named the Second component, and similarly, the Second component may be named the First component. The terms and / or include combinations of multiple related descriptions or any one of multiple related descriptions.

[0026] When it is stated that one component is “linked” or “connected” to another component, it should be understood that it may be directly linked to or connected to the other component, but that other components may exist in between. Conversely, when it is stated that one component is “directly linked” or “directly connected” to another component, it should be understood that there are no other components in between.

[0027] The terms used in this application are used solely to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. It should be understood that in this application, terms such as “includes” or “having” do not preemptively exclude the possibility of the presence or addition of features, figures, stages, actions, components, parts, or combinations thereof as described in the specification.

[0028] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as they would be generally understood by a person of ordinary skill in the art to which this invention pertains.

[0029] Terms as defined in commonly used dictionaries should be interpreted to have meanings consistent with their meanings in the context of the relevant technology, and not in an ideal or overly formal sense unless explicitly defined in this application.

[0030] Furthermore, the various configurations, processes, steps, or methods included in each embodiment of the present invention can be shared to the extent that they are not technically contradictory.

[0031] Figure 1 shows the configuration of a phase detection system according to one embodiment of the present invention.

[0032] Referring to Figure 1, a phase detection system 100 according to one embodiment of the present invention includes a phase detection device 110 and a server 120.

[0033] The phase detection system 100 detects the three-dimensional shape of the object to be detected in real time. The phase detection system 100 detects the three-dimensional shape of the object to be detected (e.g., semiconductor, display element, etc.) by measuring the optical properties of the object light reflected from the object. Here, the measured optical properties include the phase, amplitude, and polarization components of the object light.

[0034] As described above, the phase detection device 110 detects the three-dimensional shape of the object to be detected in real time and transmits the detection result to the server 120. The phase detection device 110 can be implemented in computing devices for product acceptance testing in various industrial fields, such as PCs, servers, microservers, edge computing servers performing MEC (Multi-Access Edge Computing), kiosks, or non-mobile computing devices, and can perform the operations described above.

[0035] The phase detection device 110 communicates with the server 120 using a network interface (not shown). The network interface (not shown) may be implemented as a short-range wireless communication unit, such as a Bluetooth® communication unit, a BLE (Bluetooth® Low Energy) communication unit, a Near Field Communication unit, a WLAN (Wi-Fi) communication unit, a Zigbee® communication unit, an infrared (IrDA, infrared Data Association) communication unit, a WFD (Wi-Fi Direct) communication unit, a UWB (Ultra Wideband) communication unit, or an Ant+ communication unit. The phase detection device 110 can share the optical characteristics of the object to be detected and the three-dimensional shape detected therefrom with the server 120 using the network interface (not shown).

[0036] The server 120 communicates with the phase detection device 110 and receives detection results from the phase detection device 110.

[0037] Figure 2 shows the configuration of a phase detection device according to one embodiment of the present invention, and Figure 11 is a diagram illustrating the detection process of the optical characteristics of a phase detection device according to one embodiment of the present invention.

[0038] Referring to Figure 2, the phase detection device 110 according to one embodiment of the present invention includes an interferometer 210, an optical mask 220, a detection unit 230, a control unit 240, and a memory unit 250.

[0039] The interferometer 210 irradiates the object to be detected with light to generate interference light that includes the optical properties of the object. The interferometer 210 may be implemented with the structure shown in Figure 3.

[0040] Figure 3 shows the configuration of an interferometer according to one embodiment of the present invention.

[0041] Referring to Figure 3, an interferometer 210 according to one embodiment of the present invention includes a light source 310 and a beam splitter 320.

[0042] The light source 310 shines light towards the beam splitter 320.

[0043] The beam splitter 320 splits the light emitted from the light source 310 to the detection target 130 and the reference mirror 140, and causes the light reflected from each target 130 and 140 to proceed along the same path. The beam splitter 320 splits the light emitted from the light source 310 to the detection target 130 and the reference mirror 140, forming object light reflected from the detection target 130 and reference light reflected from the reference mirror 140. The beam splitter 320 causes both light to proceed along the same path and interfere by reflecting one of the object light and the reference light and transmitting the other.

[0044] The interferometer 210 is implemented with this structure to generate interference light that includes the optical properties of the object to be detected, and to propagate the interference light to the optical mask 220.

[0045] Figure 3 shows that the interferometer 210 includes only the beam splitter 320, but it is not necessarily limited to this; it can be replaced with any two-beam interferometer, including a Mach-Zehnder interferometer or a Sagnac interferometer.

[0046] Referring again to Figure 2, the optical mask 220 receives interference light that has passed through the interferometer 210 and generates multiple phase transition interference fringes. By using a geometrical phase optical element, the optical mask 220 can generate multiple phase transition interference fringes without including multiple imaging or detection units as in conventional systems. The specific structure and operation of the optical mask 220 are shown in Figures 4 to 10.

[0047] Figure 4 shows the configuration of an optical mask according to one embodiment of the present invention.

[0048] Referring to Figure 4, the optical mask 220 according to one embodiment of the present invention includes an optical array 410 and a circularly polarized beam splitter 420.

[0049] The optical array 410 induces a phase shift upon receiving interference light interfered by the interferometer 210, and induces its own phase shifts at multiple different angles relative to the interference light.

[0050] As shown in Figures 5 and 6, the optical array 410 is implemented using geometric phase optical elements to induce a phase transition with respect to incident interference light.

[0051] Figure 5 illustrates the optical properties of an optical array according to one embodiment of the present invention, Figure 6 shows the material properties of the materials constituting the optical array according to one embodiment of the present invention, and Figure 7 shows the structure of an optical array according to one embodiment of the present invention.

[0052] The optical array 410 is realized using geometric phase optical elements. The optical array 410 may be realized using a structure having a meta surface as shown in Figure 6A, or using a structure containing liquid crystal.

[0053] The optical array 410 may be realized as a structure having a metasurface, as shown in Figure 6A. The anisotropic structure 610 having a metasurface is formed of a high refractive index material having a rectangular cross-section and a high prismatic shape, and may be arranged in a rotated form for each local position. The rectangular cross-section of the high refractive index material having a nanosize smaller than the wavelength of radio waves exhibits optical anisotropy, and its rotational arrangement induces rotation of the optical axis. The anisotropic structure 610 having a metasurface can be manufactured by an E-beam lithography process or a semiconductor process for precisely fabricating nanoscale structures.

[0054] Alternatively, the optical array 410 may be realized as a liquid crystal-based anisotropic structure 610, as shown in Figure 6B. Since the liquid crystal-based anisotropic structure 610 itself exhibits the properties of anisotropic material, the structure 610 can be arranged in a rotated form, such as the arrangement of the Φ(x) values ​​which are the alignment direction of the liquid crystals, at each local position, thereby inducing a geometrical phase effect. When the optical array 410 is realized as a liquid crystal-based anisotropic structure, it can be produced relatively inexpensively.

[0055] Thus, the optical array 410 realized with geometric phase optical elements has the optical properties shown in Figure 5. The optical array 410 generates an additional geometric phase shift phenomenon due to the difference in the optical axis direction of the anisotropic material. As a result, when the optical array 410 is realized with an anisotropic material having Γ as a phase retardance, the following emitted light is produced when light with unidirectional circular polarization is incident on the optical array 410.

[0056] JPEG2026509338000002.jpg2987

[0057] JPEG2026509338000003.jpg18110

[0058] JPEG2026509338000004.jpg3195

[0059] JPEG2026509338000005.jpg1229

[0060] Here, T is the Jones matrix, E in The incident light incident on the optical array 410 is E GP The light emitted from the optical array 410 is used to... JPEG2026509338000006.jpg87 is right-circularly polarized, JPEG2026509338000007.jpg76 is left-circularly polarized light, θ is the rotation angle of the optical axis of an anisotropic material, ne The refractive index of the fast axis of an anisotropic material is n o t represents the refractive index of the slow axis of the anisotropic material, and t represents the thickness of the anisotropic material in the direction of light propagation.

[0061] According to the aforementioned formula, when light of one polarization is incident on the optical array 410, the same polarization component as the incident light (the component containing the cos term in the formula related to the emitted light) and the opposite polarization component (the component containing the sin term in the formula related to the emitted light), which is phase-shifted (delayed) by twice the rotation angle of the optical axis of the anisotropic material, are emitted.

[0062] On the other hand, the optical array 410 having these characteristics, as shown in Figure 7, is made of an anisotropic material that induces a geometrical phase effect and includes a plurality of optical pixels 710 that are realized in an array-like manner.

[0063] In this case, instead of each optical pixel 710 receiving interference light from different points (of the detection target) as in the conventional method, multiple (at least three) adjacent optical pixels 710a to 710d receive interference light from the same point (of the detection target). However, each optical pixel 710 that receives interference light from the same point is realized from an anisotropic material having the same properties as described above and has different optical axis rotation angles. For example, as illustrated in Figure 7, if we assume that four optical pixels 710a to 710d adjacent to each other in the horizontal (x-axis direction) and vertical (y-axis) directions receive interference light from the same point, each optical pixel 710a to 710d can have optical axis rotation angles of 0°, 45°, 90°, and 135°.

[0064] As a result, the polarization components of the incident light passing through each optical pixel 710a to 710d that undergo a phase transition (delay) experience phase transitions of 0°, 90°, 180°, and 270°, which are twice the optical axis rotation angle.

[0065] Thus, when n is the number of optical pixels 710a to 710d that are incident on the same point within the optical array 410, and Λ is the size of the pixels in the detection unit 230, the optical pixels 710a to 710d within the optical array 410 can be arranged in a repeating pattern with a period of nΛ. In Figure 7, the optical pixels 710a to 710d are arranged adjacent to each other horizontally and vertically, so they can be arranged in a repeating pattern with a period of 2Λ in both the horizontal and vertical directions within the optical array 410.

[0066] An optical array 410 having such an arrangement of optical pixels 710 can acquire all phase transition interference fringes for optical characteristic analysis of the object to be detected, even if it receives interference light only once. As a result, the optical array 410 can fundamentally block the influence of disturbances such as vibrations during the process of acquiring all interference fringes with different phase transition angles, as in conventional systems, and does not require multiple detection units. Since only an extremely thin optical mask 220 needs to be placed in front of a single detection unit 230, it is possible to have a simple structure, and the total volume of the optical mask 220 or the phase detection device 110 including it can be very small.

[0067] Referring again to Figure 4, the light of each polarization component emitted from the optical array 410 is incident on the circularly polarized beam splitter 420. The circularly polarized beam splitter 420 has the characteristics shown in Figure 8 and can operate as shown in Figure 9.

[0068] Figure 8 shows the structure and chiral volume grating characteristics of a circularly polarized beam splitter according to one embodiment of the present invention, Figure 9 illustrates the optical characteristics of a circularly polarized beam splitter according to one embodiment of the present invention, and Figure 10 illustrates the optical characteristics of an optical mask according to one embodiment of the present invention.

[0069] Referring to Figure 8, the circularly polarized beam splitter 420 has a helical structure, i.e., chiral properties. An element in which the molecular orientation of an anisotropic structure 810 is sequentially rotated and aligned along the vertical axis (y-axis) is called a chiral element. For example, if a chiral dopant is added to a nematic liquid crystal in which all liquid crystal molecules are oriented in a certain direction, the chiral dopant can induce chiral alignment of the nematic liquid crystal. At this time, the period T of the chiral properties y This can be determined depending on the concentration of the chiral dopant.

[0070] Furthermore, various methods are used to align the boundary surfaces of liquid crystals during a period T x When aligned to have a specific characteristic, a chiral liquid crystal alignment layer can be fabricated using a volume grating. Generally, light propagation in a volume grating satisfies the Bragg diffraction condition between the propagation constants of the incident and exit light and the grating vector, according to Floquet's theorem.

[0071] Under these conditions, the circularly polarized beam splitter 420 operates as shown in Figure 9. The circularly polarized beam splitter 420 reflects the circularly polarized component of the light incident on it that has the same rotation direction as its helical structure, and transmits the circularly polarized component that rotates in the opposite direction. More specifically, the volume grating characteristic appears selectively in the circularly polarized beam splitter 420 depending on the circular polarization direction of the incident light, so it can function as a selective mirror or beam splitter depending on the polarization direction of the incident light. For example, if the circularly polarized beam splitter 420 has left helicity as shown in Figure 9, it can reflect the left circularly polarized component of the light incident on it and transmit only the right circularly polarized component.

[0072] The optical mask 220 operates as shown in Figure 10 by including an optical array 410 having the characteristics described above and a circularly polarized beam splitter 420.

[0073] As described above, when object light polarized in one direction (e.g., left circular polarization) and reference light polarized in another direction (e.g., right circular polarization) are incident on the optical array 410, each light passes through the optical array 410 and is emitted as the same polarization component as the incident light without phase transition and as the opposite polarization component with phase transition.

[0074] Light emitted from the optical array 410 enters the circularly polarized beam splitter 420, where only one polarization component (for example, left-circularly polarized light) is reflected, and the remaining polarization component is transmitted. One of the transmitted polarization components is light with no phase transition, while the other corresponds to light whose phase has transitioned by twice the optical axis rotation angle. The components transmitted through the circularly polarized beam splitter 420 interfere with each other, forming interference fringes, which then propagate to the detection unit 230.

[0075] For example, if the thickness (Γ) of the optical array 410 is adjusted to π / 2, the interference fringes shown below will be formed in the interference light that has passed through the optical mask 220.

[0076] JPEG2026509338000008.jpg1525

[0077] JPEG2026509338000009.jpg3888

[0078] JPEG2026509338000010.jpg54131

[0079] Here, JPEG2026509338000011.jpg88 contains the object light component of the incident light, JPEG2026509338000012.jpg88 contains the reference light component of the incident light, JPEG2026509338000013.jpg88 shows the object light component transmitted through the optical array 410. JPEG2026509338000014.jpg88 represents the reference light components transmitted through optical array 410.

[0080] Referring again to Figure 2, the detection unit 230 receives multiple phase transition interference fringes transmitted through the optical mask 220 and measures the optical properties of the object light reflected from the detection target based on the received interference fringes. As shown in Figure 12, the detection unit 230 can acquire (multiple) phase transition interference fringe images that have transitioned by the same angle relative to each other according to the rotation angle of the optical axis.

[0081] Figure 12 shows the pixel structure of phase-transitioned interference fringes detected by a detection unit according to one embodiment of the present invention.

[0082] Referring to Figures 12A and 12B, the detection unit 230 can group multiple interference fringes that have undergone the same phase transition angle relative to each other according to the rotation angle of the optical axis, and can acquire multiple phase transition interference fringes. The detection unit 230 can detect the optical properties (phase, amplitude, polarization) of the object light from the acquired multiple phase transition interference fringes.

[0083] Since the detection unit 230 can receive at least three interference fringes that have transitioned at different angles from the optical mask 220, it can detect the amplitude of the object light, the amplitude of the reference light, and the phase of the object light relative to the reference light, as follows.

[0084] JPEG2026509338000015.jpg2152

[0085] JPEG2026509338000016.jpg1380

[0086] JPEG2026509338000017.jpg1474

[0087] JPEG2026509338000018.jpg1374

[0088] JPEG2026509338000019.jpg1582

[0089] Through the process described above, the detection unit 230 can detect the phase and amplitude of the object light.

[0090] Furthermore, the detection unit 230 can detect the polarization state of object light using multiple interference fringes that are received. The detection unit 230 can detect Stokes' parameters ({S0, S1, S2, S3}) that indicate the polarization of light from the amplitude of left circular polarization, the phase of left circular polarization, the amplitude of right circular polarization, and the phase of right circular polarization. The detection unit 230 can detect the Stokes parameters using the following formula.

[0091] JPEG2026509338000020.jpg868

[0092] JPEG2026509338000021.jpg13107

[0093] JPEG2026509338000022.jpg1350

[0094] JPEG2026509338000023.jpg12103

[0095] JPEG2026509338000024.jpg1754

[0096] Here, Ar controls the amplitude of right-circularly polarized light, φ r φ represents the phase of right-circularly polarized light, Al represents the amplitude of left-circularly polarized light, and φ represents the phase of right-circularly polarized light. l These represent the phases of left-circularly polarized light, respectively.

[0097] At this time, each Stokes parameter is calculated as follows:

[0098] JPEG2026509338000025.jpg2640

[0099] The detection unit 230 can detect the polarization state from the amplitude and phase of the object light, as described above.

[0100] As a result, even if the phase detection device 110 receives interference light from the object to be detected only once, the detection unit 230 can detect the optical properties of the object's light. This allows the detection unit 230 to detect the three-dimensional shape (of the object to be detected) with a pixel size of Λ.

[0101] Referring again to Figure 2, the control unit 240 controls the aforementioned operations of each component within the phase detection device 110. The control unit 240 can control the aforementioned operations of each component within the phase detection device 110 by executing a program stored in the memory unit 250. Furthermore, the control unit 240 may be composed of one or more processors, and may be implemented as a general-purpose processor such as a CPU, AP, or DSP (Digital Signal Processor), or as a graphics-dedicated processor such as a GPU or VPU (Vision Processing Unit).

[0102] The memory unit 250 can store one or more instructions that enable the aforementioned operations of each component within the phase detection device 110.

[0103] The memory unit 250 may be implemented using flash memory type, hard disk type, multimedia card micro type, card type memory (e.g., SD or XD memory), RAM (Random Access Memory), SRAM (Static Random Access Memory), ROM (Read-Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), PROM (Programmable Read-Only Memory), magnetic memory, magnetic disk, or optical disk.

[0104] Figure 13 is a flowchart showing a method by which a phase detection device according to one embodiment of the present invention detects the optical characteristics of a target object.

[0105] The detection unit 230 detects interference fringes of object light and reference light that have passed through the optical mask 220 (S1310). The detection unit 230 detects interference fringes formed by object light that has been transmitted through the optical mask 220 and is polarized in the same direction as reference light.

[0106] The detection unit 230 groups the detected interference fringes according to the optical axis rotation angle of the geometric phase optical pixels and acquires multiple interference fringe images (S1320).

[0107] The detection unit 230 detects the optical properties of object light using multiple interference fringe images acquired (S1330).

[0108] Although Figure 13 shows each process being executed sequentially, this is merely an example illustrating the technical concept of one embodiment of the present invention. In other words, anyone with ordinary skill in the technical field to which one embodiment of the present invention belongs can modify and adapt the order shown in each drawing, or execute one or more of the processes in parallel, without departing from the essential characteristics of one embodiment of the present invention. Therefore, Figure 13 is not limited to a chronological order.

[0109] On the other hand, the process shown in Figure 13 can be implemented as computer-readable code on a computer-readable recording medium. A computer-readable recording medium includes all types of recording devices that store data readable by a computer system. That is, a computer-readable recording medium includes storage media such as magnetic storage media (e.g., ROM, floppy disks, hard disks, etc.) and optical reading media (e.g., CD-ROM, DVD, etc.). Furthermore, computer-readable recording media can store and execute computer-readable code in a distributed manner across computer systems connected via a network.

[0110] The above description is merely an example illustrating the technical concept of this embodiment, and a person with ordinary skill in the art to which this embodiment belongs could make various modifications and variations without departing from the essential characteristics of this embodiment. Therefore, this embodiment is for illustrative purposes only, not to limit the technical concept of this embodiment, and the scope of the technical concept of this embodiment is not limited by such an embodiment. The scope of protection of this embodiment should be interpreted in accordance with the following claims, and all technical concepts within an equivalent scope should be interpreted as being included in the scope of rights of this embodiment.

[0111] CROSS-REFERENCE TO RELATED APPLICATION

[0112] This patent application claims priority under Section 119(a) of the United States Patent Act (35 U.S.SC § 119(a)) to Patent Application No. 10-2023-0032567 filed in Korea on March 13, 2023, and all its contents are incorporated into this patent application as references. In addition, this patent application claims priority in countries other than the United States for the same reasons as above, and all its contents are incorporated into this patent application as references.

Claims

1. It includes an optical mask that causes a phase transition between object light and reference light, which have different circular polarizations and are generated by an interferometer. The aforementioned optical mask is An optical array including a plurality of optical pixels that induce a geometric phase effect that delays the object light and the reference light by twice a predetermined optical axis rotation angle, A phase detection device comprising a circularly polarized beam splitter configured to transmit a portion of the circularly polarized components that have passed through the optical array.

2. The aforementioned interferometer is A light source that provides false interference light, The phase detection device according to claim 1, comprising a light source beam splitter that splits light into object light and reference light.

3. The aforementioned circularly polarized beam splitter is The phase detection device according to claim 1, characterized in that the anisotropic material or anisotropic structure is formed in a helical structure.

4. The aforementioned circularly polarized beam splitter is The phase detection device according to claim 3, characterized in that it reflects circularly polarized light rotating in the same direction as the helical structure and transmits circularly polarized light rotating in the opposite direction.

5. The phase detection device according to claim 1, further comprising a detection unit for detecting interference fringes formed by object light and reference light transmitted through the circularly polarized beam splitter.

6. The detection unit is The phase detection device according to claim 5, characterized by acquiring multiple phase transition interference fringe images.

7. The optical array is The phase detection device according to claim 1, characterized in that when light of one polarization is incident, it emits a polarization component identical to the incident light and an opposite polarization component that is phase-delayed by twice the optical axis rotation angle.

8. The aforementioned optical pixel is The phase detection device according to claim 7, characterized in that object light from the same point is incident between a plurality of adjacent optical pixels.

9. Each adjacent optical pixel is, The phase detection device according to claim 8, characterized in that the optical axes have different rotation angles.

10. The aforementioned optical pixel is The phase detection device according to claim 8, characterized in that object light from the same point is incident between at least three or more adjacent optical pixels.

11. In a method for detecting the phase of object light using a phase detection device, A detection process that detects interference fringes of object light and reference light detected by the detection unit after passing through an optical mask, The acquisition process involves grouping the interference fringes detected in the aforementioned detection process according to the rotation angle of the optical axis of the geometric phase optical pixel to obtain multiple interference fringe images. A detection process for detecting the optical properties of object light using multiple interference fringe images obtained in the aforementioned acquisition process, A phase detection method characterized by including the following:

12. The aforementioned optical mask is An optical array including geometric phase optical pixels that phase-delay the object light and the reference light by twice a predetermined optical axis rotation angle, The phase detection method according to claim 11, further comprising a circularly polarized beam splitter configured to transmit a portion of the circularly polarized components transmitted through the optical array.

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