TWI898815B - Phase detection method - Google Patents

Abstract

The present invention discloses a phase detection device using a phase shifting method using a geometric phase optics device. According to one embodiment of the present invention, the phase detection device includes an optical mask that phase-shifts object light and reference light having different circular polarizations generated by an interferometer. The optical mask comprises an optical array including geometric phase optics pixels that phase-delay the object light and reference light by twice a predetermined optical axis rotation angle, and a circularly polarized beam splitter that transmits a portion of the circularly polarized light components transmitted through the optical array.

Description

Phase detection method

This embodiment relates to a phase detection device that uses a geometric phase optical device to detect the optical properties of object light in a phase-shifting manner.

The content described in this section only provides background information for this embodiment and does not constitute prior art.

Optical inspection technology has evolved from traditional 2D shape inspection to 3D shape inspection. Various technologies attempt to detect the phase and polarization characteristics of light reflected from an object, including the intensity. Among these, phase-shifting interferometry (PSI) has become a fundamental method for 3D shape measurement due to its simple optical system and computational algorithm.

Conventional phase-shifting methods use devices such as piezoelectric transducers (PZTs) or liquid crystal variable retarders (LCVRs) to detect the intensity and phase of object light reflected from an object's surface. Conventional phase-shifting methods sequentially adjust the phase of reference light reflected from a reference lens to capture multiple phase-shifted interference fringes, which they then use to detect this information.

However, conventional phase-shifting methods require multiple shots accompanied by sequential adjustment of the PZT or LCVR to generate phase-shifted interference fringes. This results in a slight time lag in the generation of the phase-shifted interference fringes. When irregular vibrations are introduced from the environment during these time lags, conventional phase-shifting methods suffer from a degradation in phase detection performance. However, in the real world of mass-production, various irregular vibrations are common, making it difficult to expect high phase detection performance from conventional phase-shifting methods in these industrial settings.

As a method to avoid errors caused by vibration, studies are underway to use multiple cameras to simultaneously capture multiple phase-shift interference fringes. However, this method requires precise alignment of the pixels of each camera corresponding to the same position on the object, requiring a separate device or process for alignment. Furthermore, this method requires additional space for multiple cameras, making it difficult to implement a compact optical system. The use of multiple expensive cameras also has the disadvantage of increasing the cost of the inspection equipment.

Therefore, there is a need to develop a new phase detection device technology that overcomes the weakness of conventional phase shift methods in time-series imaging, avoids the use of multiple cameras, and has a simple structure and inexpensive optical systems.

An object of one embodiment of the present invention is to provide a phase detection device that utilizes a geometric phase optical device to detect optical characteristics of object light while having a simple structure and being stronger than external vibration.

According to one embodiment of the present invention, a phase detection device is provided, characterized by including an optical mask that phase-shifts object light and reference light having different circular polarizations generated by an interferometer. The optical mask includes an optical array comprising geometric phase optical pixels that phase-delay the object light and reference light by twice a predetermined optical axis rotation angle, and a circularly polarized beam splitter that transmits a portion of the circularly polarized light components that pass through the optical array.

According to one embodiment of the present invention, the interferometer includes: a light source for providing interferable light; and a light source beam splitter for splitting the light into object light and reference light.

According to one embodiment of the present invention, the anisotropic material or anisotropic structure in the circularly polarized beam splitter is formed of a spiral structure.

According to one embodiment of this embodiment, the circularly polarized light beam splitter reflects circularly polarized light that rotates in the same direction as the spiral structure, and transmits circularly polarized light that rotates in the opposite direction.

According to one embodiment of the present invention, the phase detection device further includes a detection unit for detecting interference fringes formed by the object light and the reference light passing through the circularly polarized beam splitter.

According to one embodiment of this embodiment, the detection unit obtains multiple phase-shifted interference fringe images.

According to one embodiment of the present invention, when incident on a polarized light, the optical array emits a light component with the same polarization as the incident light and a light component with an opposite polarization that is delayed by twice the optical axis rotation angle.

According to one embodiment of the present invention, the optical pixel receives object light incident on the same location between adjacent optical pixels.

According to one embodiment of the present invention, adjacent optical pixels have different optical axis rotation angles.

According to one embodiment of the present invention, the optical pixel receives object light incident on the same location between at least three adjacent optical pixels.

According to one embodiment of the present invention, a phase detection method is provided. A phase detection device detects the phase of object light, characterized by comprising: a detection process of detecting interference fringes between object light and reference light detected by a detection unit through an optical mask; an acquisition process of grouping the interference fringes detected in the detection process according to the optical axis rotation angle of a geometric phase optical pixel to obtain a plurality of interference fringes images; and a detection process of detecting the optical characteristics of the object light using the plurality of interference fringes images obtained in the acquisition process.

According to one embodiment of the present invention, the optical mask includes: an optical array comprising geometric phase optical pixels that cause the object light and the reference light to have a phase delay of twice a predetermined optical axis rotation angle; and a circularly polarized beam splitter that transmits a portion of the circularly polarized light components that pass through the optical array.

As described above, according to one embodiment of the present invention, it has the advantage of being able to detect the optical characteristics of object light while utilizing a geometric phase optical device having a simple structure.

Furthermore, according to one embodiment of the present invention, multiple phase-shifted interference fringe images can be obtained with just one shot, which has the advantage of being stronger than external vibrations.

100: Phase detection system

110: Phase detection device

120: Server

130: Detection object

140: Benchmark lens

210: Interferometer

220: Optical mask

230: Testing Department

240: Control Department

250: Storage Unit

310: Light Source

320: Beam splitter

410: Optical Array

420: Circularly Polarized Beam Splitter

610, 810: Anisotropic structures

710a~710d: Optical pixels

S1310, S1320, S1330: Steps

T _x , _Ty : period

Λ: Size

θ: Optical axis rotation angle

FIG1 is a diagram showing the structure of a phase detection system according to one embodiment of the present invention.

Figure 2 is a diagram showing the structure of a phase detection device according to one embodiment of the present invention.

FIG3 is a diagram showing the structure of an interferometer according to an embodiment of the present invention.

FIG4 is a diagram showing the structure of an optical mask according to an embodiment of the present invention.

FIG5 is a diagram illustrating the optical characteristics of an optical array according to an embodiment of the present invention.

Figures 6a and 6b are diagrams showing the material properties of the material constituting the optical array according to one embodiment of the present invention.

FIG7 is a diagram showing the structure of an optical array according to an embodiment of the present invention.

Figure 8 is a diagram showing the structure of a circularly polarized beam splitter and the characteristics of a chiral volume grating according to an embodiment of the present invention.

FIG9 is a diagram illustrating the optical characteristics of a circularly polarizing beam splitter according to an embodiment of the present invention.

FIG10 is a diagram illustrating the optical characteristics of an optical mask according to an embodiment of the present invention.

FIG11 is a diagram illustrating the optical characteristic detection process of a phase detection device according to an embodiment of the present invention.

Figures 12a and 12b are diagrams showing the pixel structure of phase-shifted interference fringes detected by a detection unit according to one embodiment of the present invention.

FIG13 is a flow chart showing a method for detecting optical characteristics of a detection object using a phase detection device according to an embodiment of the present invention.

This invention is susceptible to numerous modifications and embodiments, and specific embodiments are illustrated in the figures for detailed description. However, the invention is not limited to any specific embodiment and should be understood to encompass all modifications, equivalent technical solutions, and even alternative technical solutions within the spirit and technical scope of the invention. Similar reference numbers will be used to represent similar structural elements in the description of the various figures.

Terms such as "first," "second," "A," and "B" may be used to describe various structural elements, but the structural elements described above should not be limited to these terms. These terms are used solely to distinguish one structural element from another. For example, a first structural element may be referred to as a second structural element, and similarly, a second structural element may be referred to as a first structural element without departing from the scope of the present invention. The term "and/or" includes a combination of multiple related items or one of the multiple related items.

When a structural element is "connected" or "connected" to another structural element, it may be directly connected or connected to the other structural element, but it should be understood that other structural elements may exist in between. Conversely, when a structural element is "directly connected" or "directly connected" to another structural element, it should be understood that no other structural elements exist in between.

The terms used in this application are intended only to describe specific embodiments and are not intended to limit the present invention. Singular expressions include the plural unless the context clearly indicates a different meaning. Terms such as "including" or "having" in this application should be understood as not precluding the presence or additional possibility of features, numbers, steps, actions, structural elements, components, or combinations thereof described in the specification.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

Terms such as those defined in commonly used dictionaries should be interpreted as having meanings consistent with the context of the relevant technology and should not be interpreted as ideal or overly formal meanings unless otherwise expressly defined in this application.

Furthermore, the various structures, processes, procedures, or methods included in the various embodiments of the present invention may be shared within the scope of technical non-inconsistency.

FIG1 is a diagram showing the structure of a phase detection system according to one embodiment of the present invention.

1 , a phase detection system 100 according to an embodiment of the present invention includes a phase detection device 110 and a server 120.

Phase detection system 100 detects the three-dimensional shape of a detection object in real time. Phase detection system 100 measures the optical properties of object light reflected from the detection object (e.g., a semiconductor, display device, etc.) to detect the three-dimensional shape of the detection object. The measured optical properties include the phase, amplitude, and polarization components of the object light.

As described above, phase detection device 110 detects the three-dimensional shape of the detection object in real time and transmits the detection results to server 120. Phase detection device 110 can be implemented in various industries, such as computing devices used for product acceptance, PCs, servers, microservers, edge computing servers implementing Multi-Access Edge Computing (MEC), self-service terminals, or non-mobile computing devices, to perform the aforementioned operations.

Phase detection device 110 communicates with server 120 via a network interface (not shown). The network interface (not shown) can be implemented by a short-range wireless communication unit, a Bluetooth communication unit, a Bluetooth Low Energy (BLE) communication unit, a near-field communication unit, a WLAN (Wi-Fi) communication unit, a Zigbee communication unit, an infrared (IrDA) communication unit, a Wi-Fi Direct (WFD) communication unit, an ultra-wideband (UWB) communication unit, or an Ant+ communication unit. Phase detection device 110 can share the optical characteristics of the detection object and the three-dimensional shape detected thereby with server 120 via the network interface (not shown).

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

Figure 2 shows the structure of a phase detection device according to an embodiment of the present invention, and Figure 11 illustrates the optical characteristic detection process of the phase detection device according to an embodiment of the present invention.

2 , a phase detection device 110 according to an embodiment of the present invention includes an interferometer 210, an optical mask 220, a detection unit 230, a control unit 240, and a storage unit 250.

Interferometer 210 irradiates light onto the object to be detected, generating interference light that reflects the optical characteristics of the object. Interferometer 210 can be implemented using the structure shown in Figure 3.

FIG3 is a diagram showing the structure of an interferometer according to an embodiment of the present invention.

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

The light source 310 irradiates light toward the beam splitter 320.

The beam splitter 320 splits the light emitted from the light source 310 toward the object 130 and the reference mirror 140, causing the light reflected from each object 130 and 140 to follow the same path. The beam splitter 320 splits the light emitted from the light source 310 toward the object 130 and the reference mirror 140, forming object light reflected from the object 130 and reference light reflected from the reference mirror 140. By reflecting one of the object light and the reference light and transmitting the other, the beam splitter 320 causes the two lights to follow the same path, causing them to interfere.

The interferometer 210 is implemented with this structure to generate interference light that includes the optical characteristics of the object to be detected and directs the interference light toward the optical mask 220.

FIG3 shows interferometer 210 as including only beam splitter 320, but the present invention is not limited thereto. Any two-beam interferometer, such as a Mach-Zehnder interferometer or a Sagnac interferometer, may be substituted.

Referring again to Figure 2 , optical mask 220 generates multiple phase-shifted interference fringes when interfering light passing through interferometer 210 is incident on it. Optical mask 220 utilizes geometric phase optics, allowing it to generate multiple phase-shifted interference fringes without requiring multiple imaging or detection units, as is conventional practice. The specific structure and operation of optical mask 220 are shown in Figures 4 through 10 .

FIG4 is a diagram showing the structure of an optical mask according to an embodiment of the present invention.

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

The optical array 410 induces phase shift in the interferometer 210 when the interfering light enters the interferometer 210. The optical array 410 itself induces phase shift in the interfering light at multiple different angles.

As shown in Figures 5, 6a, and 6b, the optical array 410 is implemented using geometric phase optics, which induces a phase shift in the incident interference light.

Figure 5 illustrates the optical properties of an optical array according to an embodiment of the present invention. Figures 6a and 6b illustrate the physical properties of materials constituting the optical array according to an embodiment of the present invention. Figure 7 illustrates the structure of the optical array according to an embodiment of the present invention.

Optical array 410 is implemented using a geometric phase optical device. Optical array 410 can be implemented using a structure having a metasurface (as shown in Figure 6a), or a structure including liquid crystal.

Optical array 410 can be implemented using a structure with a metasurface, as shown in Figure 6a. Anisotropic metasurface structure 610 can be formed from a high-refractive-index material with a rectangular cross-section and tall columns, arranged in a locally rotated configuration. The rectangular cross-section of the high-refractive-index material, with nanometer-sized structures smaller than the propagation wavelength, exhibits optical anisotropy, and this rotated configuration induces rotation of the optical axis. Anisotropic metasurface structure 610 can be fabricated using electron beam lithography or semiconductor processes, which are used to precisely fabricate nanoscale structures.

Alternatively, as shown in Figure 6b, the optical array 410 can be implemented using an anisotropic liquid crystal structure 610. The anisotropic liquid crystal structure 610 inherently exhibits the properties of an anisotropic material. Therefore, the structure 610 can be arranged in a configuration where each local position rotates with respect to the Φ(x) value, which is the alignment direction of the liquid crystal, inducing a geometric phase effect. When the optical array 410 is implemented using an anisotropic liquid crystal structure, it can be produced relatively inexpensively.

Thus, optical array 410 implemented using geometric phase optics exhibits the optical characteristics shown in Figure 5. Optical array 410 generates an additional geometric phase shift due to the difference in the optical axis direction of the anisotropic material. Therefore, when optical array 410 is implemented using an anisotropic material with Γ through phase retardation, if unidirectional circularly polarized light is incident on optical array 410, the following output light is produced.

Wherein, T represents the Jones Matrix, E ⁱⁿ represents the incident light entering the optical array 410 , and E ^GP represents the output light output from the optical array 410 . This means right circularly polarized light. represents left circularly polarized light, θ represents the optical axis rotation angle of the anisotropic material, _ne represents the refractive index of the anisotropic material along the fast axis, _no represents the refractive index of the anisotropic material along the slow axis, and t represents the thickness of the anisotropic material in the direction of light propagation.

According to the above formula, when a polarized light is incident on the optical array 410, it emits a light component with the same polarization as the incident light (the component included in the cosine term in the formula related to the outgoing light) and an oppositely polarized light component with a phase shift (delay) of twice the optical axis rotation angle of the anisotropic material (the component included in the sinine term in the formula related to the outgoing light).

On the other hand, as shown in FIG7 , an optical array 410 having such characteristics is implemented by an anisotropic material that induces a geometric phase effect and includes a plurality of optical pixels 710 a to 710 d implemented in an array form.

In this case, unlike in the prior art, the interference light incident on optical pixels 710a through 710d is not incident on different locations of each pixel (on the detection object). Instead, the interference light is incident on the same location of multiple (at least three) adjacent optical pixels 710a through 710d (on the detection object). However, the interference light incident on the same location of each optical pixel 710a through 710d is also implemented using an anisotropic material with the aforementioned properties, and thus has different optical axis rotation angles. For example, as shown in FIG7 , assuming that interference light is incident on the same location on four optical pixels 710 a to 710 d that are adjacent in the horizontal (x-axis) and vertical (y-axis) directions, each optical pixel 710 a to 710 d can have an optical axis rotation angle of 0°, 45°, 90°, or 135°.

As a result, the phase-shifted (delayed) polarization components of the incident light passing through each of the optical pixels 710a to 710d experience phase shifts of 0°, 90°, 180°, and 270°, which are twice the optical axis rotation angle.

Thus, if the number of optical pixels 710a to 710d within the optical array 410, which interfere with light incident on the same point, is set to n, and the pixel size within the detection unit 230 is set to Λ, the optical pixels 710a to 710d within the optical array 410 can be repeatedly arranged in nΛ cycles. In Figure 7, the optical pixels 710a to 710d are arranged adjacent to each other in the horizontal and vertical directions, so they can be repeatedly arranged in the optical array 410 in cycles of 2Λ in both the horizontal and vertical directions.

Optical array 410 with this configuration of optical pixels 710a to 710d can obtain all phase-shifted interference fringes used to analyze the optical characteristics of the detection target, even when interfering light is incident only once. This fundamentally eliminates the effects of disturbances such as vibrations that occur during the process of obtaining interference fringes with different phase shift angles, as in conventional systems, and eliminates the need for multiple detection units. Simply placing an extremely thin optical mask 220 at the tip of a single detection unit 230 allows for a simple structure, reducing the overall size of the optical mask 220 or the phase detection device 110 containing it.

Referring back to Figure 4 , the light of each polarization component emitted from optical array 410 is incident on circularly polarized beam splitter 420 . Circularly polarized beam splitter 420 has the characteristics shown in Figure 8 and operates as shown in Figure 9 .

Figure 8 shows the structure of a circularly polarizing beam splitter and the characteristics of a chiral volume grating according to an embodiment of the present invention. Figure 9 illustrates the optical characteristics of a circularly polarizing beam splitter according to an embodiment of the present invention. Figure 10 illustrates the optical characteristics of an optical mask according to an embodiment of the present invention.

Referring to Figure 8 , circularly polarized beam splitter 420 has a helical structure, known as chirality. A device in which the molecular orientation of anisotropic structure 810 is rotated and aligned along the longitudinal (y-axis) is called a chiral device. For example, when a chiral dopant is added to nematic liquid crystal, where all liquid crystal molecules are oriented in a predetermined direction, the chiral dopant can induce chirality in the nematic liquid crystal. In this case, the period of the chiral property, T _y, is determined by the concentration of the chiral dopant.

Furthermore, chiral liquid crystal alignment layers can be fabricated using volume grating, by utilizing various methods to align the liquid crystal boundary surface with an alignment period _Tx . Generally, light propagation within a volume grating satisfies the Bragg diffraction condition based on Floquet's theorem, which states that the propagation constants of the incident and outgoing light rays are related to their grating vectors.

With these conditions, circularly polarizing beam splitter 420 operates as shown in Figure 9. Circularly polarizing beam splitter 420 reflects circularly polarized components of incident light that have the same rotational direction as its own helical structure, while transmitting circularly polarized components rotated in the opposite direction. More specifically, circularly polarizing beam splitter 420 selectively exhibits volume grating properties depending on the circular polarization direction of the incident light, thereby selectively performing mirroring or beam splitting functions based on the polarization direction of the incident light. For example, when circularly polarizing beam splitter 420 exhibits left helicity, as shown in Figure 9, it reflects the left-handed circularly polarized component of incident light while transmitting only the right-handed circularly polarized component.

The optical mask 220 includes an optical array 410 and a circularly polarized beam splitter 420 having the aforementioned characteristics, and operates as shown in FIG10 .

As described above, when reference light of unidirectional polarization (e.g., right circular polarization) different from object light of unidirectional polarization (e.g., left circular polarization) is incident on optical array 410, each light is emitted as a polarization component identical to the incident light without phase shift and a polarization component of the opposite polarization with phase shift.

Light emitted from optical array 410 enters circularly polarized beam splitter 420, which reflects only one polarized component (for example, left circularly polarized light) and transmits the remaining polarized component. One of the transmitted polarized components is unphased, while the remaining component is phase-shifted by twice the rotation angle of the optical axis. The components transmitted through circularly polarized beam splitter 420 interfere with each other, forming interference fringes that travel toward detection unit 230.

For example, when the thickness Γ of the optical array 410 is adjusted to π/2, the interference light passing through the optical mask 220 forms the following interference fringes.

in, This means that the object light component in the incident light, This means the reference light component in the incident light. This means the object light component transmitted through the optical array 410, This means the reference light component of the transmitted optical array 410. This means that the circularly polarized beam splitter 140 is used to reflect the left circularly polarized component of the object light and transmit the right circularly polarized component. This means that the circularly polarized beam splitter 140 reflects the right circularly polarized component of the object light and transmits the left circularly polarized component.

Referring again to Figure 2 , the detection unit 230 receives light from the multiple phase-shifted 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 Figures 12a and 12b , the detection unit 230 can obtain (multiple) phase-shifted interference fringe images that are phase-shifted according to the same angle of rotation of the optical axis.

Figures 12a and 12b are diagrams showing the pixel structure of phase-shifted interference fringes detected by a detection unit according to one embodiment of the present invention.

Referring to Figures 12a and 12b, the detection unit 230 can group multiple interference fringes that are phase-shifted corresponding to the same angle according to the optical axis rotation angle, thereby obtaining multiple phase-shifted interference fringes. The detection unit 230 can detect the optical properties (phase, amplitude, and polarization) of the object light from these multiple phase-shifted interference fringes.

The detector 230 receives at least three interference fringes shifted at different angles from the optical mask 220, thereby detecting 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.

After the above process, the detection unit 230 can detect the phase and amplitude of the object light.

Furthermore, the detector 230 can detect the polarization state of the object light using the multiple interference fringes of the received light. The detector 230 can detect the Stokes parameters ({S0, S1, S2, S3}) representing the polarization of the light from the amplitude and phase of the left circularly polarized light, and the amplitude and phase of the right circularly polarized light. The detector 230 can detect the Stokes parameters according to the following formula.

Here, _Ar represents the amplitude of right circularly polarized light, _Φr represents the phase of right circularly polarized light, _A1 represents the amplitude of left circularly polarized light, and _Φ1 represents the phase of left circularly polarized light.

At this time, the Stokes parameters are calculated as follows.

S ₂ =2 A _x A _y cos(Φ _y -Φ _x ),

S ₃ =2 A _x A _y sin(Φ _y -Φ _x )

The detection unit 230 can detect the polarization state from the amplitude and phase of the object light in the same manner as described above.

This allows detection unit 230 to detect the optical properties of the object light even if phase detection device 110 only receives interference light from the object once. This allows detection unit 230 to detect the three-dimensional shape (of the object) with a pixel size of Λ.

Referring again to Figure 2 , the control unit 240 controls the aforementioned operations of the various components within the phase detector 110 . The control unit 240 controls the aforementioned operations of the various components within the phase detector 110 by executing a program stored in the storage unit 250 . Furthermore, the control unit 240 may be comprised of one or more processors, including general-purpose processors such as a central processing unit (CPU), application processor (AP), or digital signal processor (DSP), or specialized graphics processors such as a graphics processing unit (GPU) or vision processing unit (VPU).

The memory unit 250 can store one or more instructions for executing the above-mentioned operations of each component within the phase detection device 110.

The storage unit 250 can be implemented by a flash memory type, a hard disk type, a multimedia card micro type, a card memory (e.g., SD or XD memory), a random access memory (RAM), a static random access memory (SRAM), a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a programmable read-only memory (PROM), a magnetic memory, a disk, or an optical disk.

FIG13 is a flow chart showing a method for detecting optical characteristics of a detection object using a phase detection device according to an embodiment of the present invention.

The detection unit 230 detects interference fringes formed by the object light and the reference light transmitted through the optical mask 220 (step S1310). The detection unit 230 detects interference fringes formed by the reference light, which is polarized in the same direction as the single-polarized object light, transmitted through the optical mask 220.

The detection unit 230 groups the detected interference fringes according to the optical axis rotation angle of the geometric phase optical pixel to obtain multiple interference fringes images (step S1320).

The detection unit 230 uses the obtained multiple interference fringe images to detect the optical properties of the object light (step S1330).

Figure 13 depicts the execution of each process sequentially, but this is merely an example illustrating the technical concept of one embodiment of the present invention. In other words, anyone skilled in the art of one embodiment of the present invention can modify the execution sequence depicted in each figure, or perform more than one of the processes concurrently, without departing from the essential characteristics of one embodiment of the present invention. Various modifications and variations are possible for application, and therefore Figure 13 is not limited to a chronological order.

On the other hand, the process shown in FIG13 can be implemented using computer-readable code on a computer-readable recording medium. Computer-readable recording media include all types of recording devices that store data readable by a computer system. Specifically, computer-readable recording media include storage media such as magnetic storage media (e.g., read-only memory, floppy disks, hard disks, etc.) and optical retrieval media (e.g., read-only compact discs, high-density digital video discs, etc.). Furthermore, computer-readable recording media can be distributed across computer systems connected via a network, enabling the storage and execution of computer-readable code in a distributed manner.

The above description is merely an illustrative description of the technical concept of this embodiment. Anyone skilled in the art to which this embodiment pertains could make various modifications and variations without departing from the essential characteristics of this embodiment. Therefore, this embodiment is intended to illustrate the technical concept of this embodiment and is not intended to limit it. The scope of the technical concept of this embodiment is not limited to this embodiment. The scope of protection of this embodiment should be interpreted in accordance with the attached patent application, and all technical concepts within the scope equivalent to the patent application should be interpreted as being included within the scope of the patent application of this embodiment.

100: Phase detection system

110: Phase detection device

120: Server

Claims (1)

A phase detection method, in which a phase detection device detects the phase of object light, includes: a detection process of detecting interference fringes between the object light and reference light detected by a detection unit through an optical mask; an acquisition process of grouping the interference fringes detected in the detection process according to the optical axis rotation angle of geometric phase optical pixels to obtain multiple interference fringe images; and a detection process of detecting optical properties of the object light using the multiple interference fringe images obtained in the acquisition process. The optical mask includes: an optical array including geometric phase optical pixels that cause the object light and the reference light to have a phase delay of twice a specified optical axis rotation angle; and a circularly polarized beam splitter that transmits a portion of the circularly polarized light components transmitted through the optical array.