Optoelectronic adjustable beam splitter for separating arbitrary orthogonal polarization states and its working method

Abstract

The present invention proposes an optoelectronic adjustable beam splitter for separating arbitrary orthogonal polarization states and its working method, comprising: a periodically polarized optoelectronic uniaxial crystal, the optoelectronic uniaxial crystal having opposite light input surfaces and light output surfaces; a first electrode, disposed on a portion of the first surface of the optoelectronic uniaxial crystal; the first surface forming an electrode-free region in areas adjacent to the light input surface and the light output surface; a second electrode, disposed on a portion of the second surface of the optoelectronic uniaxial crystal opposite to the first surface; the second surface forming an electrode-free region in areas adjacent to the light input surface and the light output surface. The present invention can separate light beams of arbitrary orthogonal polarization states, and the direction and size of the separation angle can be controlled electrically. Compared to conventional beam splitters, the optoelectronic adjustable beam splitter proposed by the present invention is smaller in size and does not have stringent requirements on the angle of the incident light.

Description

Technical Field

[0001] The present invention relates to the field of electro-optical control, and in particular to an optoelectronic adjustable beam splitter for separating arbitrary orthogonal polarization states and a working method thereof. Background Art

[0002] A polarization beam splitter is an optical device that can separate two mutually orthogonal polarization modes of light beams and output them along different transmission paths. It is one of the most important devices in optical communication devices and is widely used in many fields such as optical communication, optical storage, and polarization imaging.

[0003] Traditional polarization beam splitters generally utilize the birefringence effect of crystals or multilayer dielectric films to separate polarized light beams near the Brewster angle. However, natural birefringent crystals require sufficient thickness to separate the two polarization states, so this type of beam splitter is limited by the properties of birefringent crystals. Polarization beam splitters with multilayer dielectric film structures that separate polarized light beams near the Brewster angle have a small wavelength range and a narrow angle range, and have high requirements for the incident wavelength and angle of the light beam. In addition, there are photonic crystal beam splitters and fiber beam splitters, but these current beam splitters can only separate a pair of orthogonal polarization states, not multiple pairs of orthogonal polarization states, and the separation angle and direction of the two orthogonal polarization states after separation cannot be controlled. Summary of the Invention

[0004] In view of this, an object of the present invention is to provide an optoelectronic tunable beam splitter for separating arbitrary orthogonal polarization states and a working method thereof, so as to solve the above-mentioned problem.

[0005] An embodiment of the present invention provides an optoelectronic tunable beam splitter for separating arbitrary orthogonal polarization states, comprising:

[0006] A periodically poled optoelectronic uniaxial crystal having an opposing light input surface and a light output surface;

[0007] A first electrode is provided on a partial area of ​​the first surface of the photoelectric uniaxial crystal; the area of ​​the first surface close to the light input surface and the light output surface forms an electrode-free area;

[0008] The second electrode is arranged in a partial area of ​​the second surface of the photoelectric uniaxial crystal opposite to the first surface; the area of ​​the second surface close to the light input surface and the light output surface forms an electrode-free area.

[0009] Preferably, it also includes:

[0010] A temperature regulating member is configured to regulate the temperature of the photoelectric uniaxial crystal.

[0011] Preferably, the temperature regulating element is a semiconductor refrigeration plate, and the photoelectric uniaxial crystal is arranged on the semiconductor refrigeration plate.

[0012] Preferably, the first electrode and the second electrode are gold films plated on the first surface and the second surface.

[0013] Preferably, the thickness of the gold film is 200 μm.

[0014] Preferably, the photoelectric uniaxial crystal is a periodically poled lithium niobate crystal. Under the action of an external electric field, the principal axis of the photoelectric uniaxial crystal moves periodically along the propagation direction of light.

[0015] An embodiment of the present invention further provides a method for operating the optoelectronically adjustable beam splitter, comprising the following steps:

[0016] Inputting positive 45-degree linear polarized light or negative 45-degree linear polarized light containing a left-handed circular polarization component and a right-handed circular polarization component as the first input light into the light input end of the photoelectric uniaxial crystal;

[0017] A direct current voltage is applied to the first electrode and the second electrode; wherein, under the action of the external electric field, the principal axis of the optoelectronic uniaxial crystal periodically moves along the propagation direction of light, and the transversely varying periodic polarization duty cycle generates an effective magnetic field gradient, which separates the light field into two opposite angles according to the spin angular momentum of the first input light, thereby separating the orthogonal polarization states of left-handed circular polarization and right-handed circular polarization;

[0018] The temperature of the photoelectric uniaxial crystal is adjusted to change the phase difference of the electrodeless area, thereby changing the effective input and output polarization states of the photoelectric uniaxial crystal, so that the photoelectric uniaxial crystal can separate the light field into two opposite angles according to positive 45-degree linear polarization and negative 45-degree linear polarization.

[0019] Preferably, the photoelectric uniaxial crystal is a periodically poled lithium niobate crystal, and the temperature of the photoelectric uniaxial crystal is adjusted by a semiconductor refrigeration plate arranged on the photoelectric uniaxial crystal.

[0020] An embodiment of the present invention further provides a method for operating the optoelectronically adjustable beam splitter, comprising the following steps:

[0021] Inputting left-handed circularly polarized light or right-handed circularly polarized light containing a positive 45-degree linear polarization component and a negative 45-degree linear polarization component as the second input light into the light input end of the photoelectric uniaxial crystal;

[0022] A DC voltage is applied to the first electrode and the second electrode. Under the action of the external electric field, the main axis of the periodically poled lithium niobate crystal periodically moves along the propagation direction of light. The transversely varying duty cycle of the periodic polarization generates an effective magnetic field gradient, which separates the light field into two opposite angles according to the spin angular momentum of the input light, thereby achieving separation of the orthogonal polarization states of positive 45-degree linear polarization and negative 45-degree linear polarization.

[0023] In summary, the above embodiment achieves the separation of light beams of various orthogonal polarization states, and the angle and direction of the separation can be controlled electrically. Compared to traditional beam splitters, the optoelectronically adjustable beam splitter proposed in this embodiment is smaller, has no stringent requirements for the angle of the incident light, can separate any orthogonal polarization state, and can electrically control the angle and direction of the separation of the two orthogonal polarizations in the output light field. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solution of the present invention, the following is a brief introduction to the drawings required for use in the implementation. Obviously, the drawings described below are only some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 Schematic diagram of a photoelectric uniaxial crystal provided by an embodiment of the present invention.

[0026] Figure 2 Schematic diagram of periodic poling of a photoelectric uniaxial crystal provided by an embodiment of the present invention.

[0027] Figure 3 Schematic diagram of an experimental device for separating arbitrary orthogonal polarization states in an embodiment of the present invention.

[0028] Figure 4(a)-Figure 4(e) Schematic diagram of the working effect of separating left-hand circular polarization and right-hand circular polarization in the first experimental example.

[0029] Figure 5(a)-Figure 5(e) Schematic diagram of the working effect of separating positive 45-degree linear polarization light and negative 45-degree linear polarization light in the second experimental example.

[0030] Figure 6 Schematic diagram of the relationship between voltage and the separation angle of the orthogonal polarization states of the output light field. DETAILED DESCRIPTION

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0032] See also Figure 1 A first embodiment of the present invention provides an optoelectronic tunable beam splitter for separating arbitrary orthogonal polarization states, comprising:

[0033] A periodically poled optoelectronic uniaxial crystal 10 has a light input surface 11 and a light output surface 12 that are opposite to each other.

[0034] In this embodiment, under the action of an external electric field, the principal axis of the periodically poled optoelectronic uniaxial crystal can periodically move along the direction of light propagation. For example, the optoelectronic uniaxial crystal can be a periodically poled lithium niobate crystal, and of course, other uniaxial crystals are also possible, and the present invention is not particularly limited thereto.

[0035] The first electrode 20 is disposed on a portion of the first surface 13 of the optoelectronic uniaxial crystal 10 , and forms an electrode-free region 14 in a region of the first surface 13 close to the light input surface 11 and the light output surface 12 .

[0036] The second electrode is provided on a portion of the second surface of the photoelectric uniaxial crystal 10 opposite to the first surface 13 , and forms an electrode-free region in the second surface near the light input surface 11 and the light output surface 12 .

[0037] In this embodiment, the first electrode 20 and the second electrode may be gold films plated on the first surface 13 and the second surface, with a thickness of approximately 200 μm. They primarily function to connect to an external power source, thereby applying an electric field to the photoelectric uniaxial crystal 10. Of course, it should be noted that in other embodiments of the present invention, conductors made of other materials may also be used as electrodes, such as silver electrodes or alloy electrodes, and the present invention is not particularly limited thereto.

[0038] In this embodiment, it should be noted that the first electrode 20 and the second electrode do not completely cover the length of the photoelectric uniaxial crystal 10 (the distance between the light input surface 11 and the light output surface 12), that is, the area of ​​the first surface 13 close to the light input surface 11 and the light output surface 12 forms an electrode-free area 14, and the area of ​​the second surface close to the light input surface 11 and the light output surface 12 forms an electrode-free area.

[0039] Since lithium niobate crystal has a ∼3×10 -5 / °C birefringence sensitivity, so the phase difference of the electrodeless region 14 can be controlled by adjusting the temperature of the optoelectronic uniaxial crystal 10, thereby changing the effective input and output polarization states of the optoelectronic uniaxial crystal 10.

[0040] Based on this, in some embodiments, in order to adjust the temperature of the photoelectric uniaxial crystal 10 , a temperature adjustment member is further included, and the temperature adjustment member is configured to be able to adjust the temperature of the photoelectric uniaxial crystal 10 .

[0041] Among them, there is heat conduction between the temperature regulating member and the photoelectric uniaxial crystal 10, so that the temperature of the photoelectric uniaxial crystal 10 can be changed. Based on this, the temperature regulating member and the photoelectric uniaxial crystal 10 can be in contact or non-contact, and these schemes are all within the protection scope of the present invention.

[0042] Particularly, in some embodiments, the temperature regulating element is a semiconductor refrigeration plate, and the photoelectric uniaxial crystal 10 is disposed on the semiconductor refrigeration plate.

[0043] The working principle of this embodiment is described in detail below.

[0044] Taking a periodically poled lithium niobate crystal as an example, the photoelectric coupling process within the periodically poled lithium niobate crystal can be described using the Pauli equation for spin-1 / 2 particles. The transversely varying duty cycle of the periodically poled lithium niobate crystal generates an effective magnetic field gradient that splits the output light field into two opposite angles based on the spin angular momentum of the incident photons.

[0045] Under the action of an external electric field, the main axis of the periodically poled lithium niobate crystal periodically moves along the propagation direction of light; when the main axis movement period is Λ=λ / |n o -n e | is equal to the polarization period of the periodically poled lithium niobate crystal, the light field will be separated into two opposite angles and emitted from the output end of the crystal; therefore, when the temperature of the periodically poled lithium niobate crystal changes, its refractive index difference |n o -n e | also changes accordingly, and the polarization period of the crystal is fixed, so it is necessary to adjust the wavelength λ of the input light to make it consistent with the principal axis motion period and the crystal polarization period. o is the refractive index of o light, n e is the refractive index of e-light.

[0046] In particular, when a voltage-stabilized source is used to apply an electric field to the photoelectric uniaxial crystal, the angle and direction of the output photon separation can be controlled by the intensity and direction of the electric field applied to the photoelectric uniaxial crystal.

[0047] The angle at which the output photons separate is affected by the strength of the electric field applied to the crystal. A higher electric field strength results in a larger separation angle, while a lower electric field strength results in a smaller separation angle. The output light field is split into two opposite angles, the directions of which are related to the direction of the electric field. For input light of the same polarization, the angles are opposite when a positive voltage is applied and when a negative voltage is applied.

[0048] In order to facilitate the understanding of the present invention, the application of the present invention will be verified through some specific experiments below.

[0049] like Figure 3 As shown, the equipment for this experiment includes:

[0050] Laser light source 30, polarization control module 40 (which includes polarizer 41, half-wave plate 42, quarter-wave plate 43), optoelectronic uniaxial crystal 10, CCD 50;

[0051] In particular, the laser light source 30 is a tunable laser, the wavelength of the laser output of which can be artificially adjusted;

[0052] The polarizer 41 is used to convert the received incident light into linearly polarized light polarized in a specified direction;

[0053] The half-wave plate 42 and the quarter-wave plate 43 are used to convert the received incident light into various polarized lights, such as circularly polarized light, 45-degree linearly polarized light, etc.

[0054] The photoelectric uniaxial crystal 30 is a periodically poled lithium niobate crystal. Under the action of an external electric field, the main axis of the crystal periodically moves along the propagation direction of light.

[0055] The CCD 50 is a charge-coupled device, which is widely used in digital photography, astronomy, and particularly in optical telemetry, optical and spectral telescopes, and high-speed photography. Of course, it is understood that other imaging methods may also be used, and the present invention is not particularly limited thereto.

[0056] First experimental example

[0057] In this experimental example, the above-mentioned optoelectronic tunable beam splitter is used to separate the left-handed circular polarization state and the right-handed circular polarization state of the input light field. The optoelectronic uniaxial crystal 10 is a periodically poled lithium niobate crystal, but can also be other uniaxial crystals with the same or similar properties, and the present invention does not impose any specific restrictions.

[0058] The laser light source 30 emits a laser beam, which is then polarized into horizontal linear polarization after passing through the polarizer 41. The laser beam then passes through the half-wave plate 42 and the quarter-wave plate 43 to convert its polarization into left-handed circular polarization. The left-handed circularly polarized light is used as the input light.

[0059] The input light is incident from the light input surface 11 of the periodically poled lithium niobate crystal and is emitted from the light output surface 12 .

[0060] A periodically poled lithium niobate crystal is placed on a semiconductor refrigeration chip used to control the temperature of the photoelectric uniaxial crystal. The semiconductor refrigeration chip is connected to a computer, and the temperature of the photoelectric uniaxial crystal is controlled in real time on the computer software.

[0061] Connect the positive and negative poles of the voltage source to the two electrodes of the periodically poled lithium niobate crystal, and apply an electric field to the periodically poled lithium niobate crystal; under the action of the external electric field, the main axis of the periodically poled lithium niobate crystal periodically moves along the propagation direction of light; when the main axis movement period is Λ=λ / |n o -n e When the polarization period is equal to that of the periodically poled lithium niobate crystal, the light field will be separated into two opposite angles and emitted from the light output surface 12 of the crystal.

[0062] At this time, a CCD 50 is placed behind the periodically poled lithium niobate crystal to capture the output light spot image. As shown in Figure 4(a), when the input light polarization is left-handed circular polarization, the output light will be deflected to the left.

[0063] Furthermore, by rotating the angles of the half-wave plate 42 and the quarter-wave plate 43, the polarization state of the light beam is changed to right-handed circular polarization. When the right-handed circularly polarized light is used as the input light, the output light will be deflected to the right, as shown in FIG4( b ); and when the input light is positive 45-degree linear polarization light or negative 45-degree linear polarization light, since both positive and negative 45-degree linear polarization lights contain left-handed circular polarization components and right-handed circular polarization components, their output light will be separated into two directions, as shown in FIG4( b ). Figure 4(c) and 4(d) As shown;

[0064] The first embodiment shows that the optoelectronic adjustable beam splitter of this embodiment can separate the left-handed circular polarization state and the right-handed circular polarization state.

[0065] Second experimental example

[0066] In this experimental example, the above-mentioned optoelectronic tunable beam splitter is used to separate the positive 45-degree linear polarization state and the negative 45-degree linear polarization state of the input light field.

[0067] In this experimental example, the photoelectric uniaxial crystal 10 is selected as a periodically poled lithium niobate crystal. Of course, it can also be other uniaxial crystals with the same or similar properties, and the present invention does not make any specific limitation.

[0068] Among them, the laser light source 30 emits a laser, and the polarization state of the laser becomes horizontal linear polarization after passing through the polarizer 41, and then the polarization state of the light beam is converted into left-handed circular polarization through the half-wave plate 42 and the quarter-wave plate 43, and the left-handed circularly polarized light is used as the input light.

[0069] The input light is incident from the light input surface 11 of the periodically poled lithium niobate crystal and is emitted from the light output surface 12 .

[0070] A periodically poled lithium niobate crystal is placed on a semiconductor refrigeration chip used to control the temperature of the photoelectric uniaxial crystal. The semiconductor refrigeration chip is connected to a computer, and the temperature of the photoelectric uniaxial crystal is controlled in real time on the computer software.

[0071] In particular, in the second experimental example, the temperature of the periodically poled lithium niobate crystal was changed by a semiconductor refrigeration plate. -5 / °C birefringence sensitivity, the phase difference of the electrodeless region 14 can be controlled by adjusting the temperature of the periodically poled lithium niobate crystal, thereby changing the effective input polarization state of the light beam.

[0072] Connect the positive and negative poles of the voltage source to the two electrodes of the periodically poled lithium niobate crystal, and apply an electric field to the periodically poled lithium niobate crystal; under the action of the external electric field, the main axis of the periodically poled lithium niobate crystal periodically moves along the propagation direction of light; when the main axis movement period is Λ=λ / |n o -n e When the polarization period is equal to that of the periodically poled lithium niobate crystal, the light field will be separated into two opposite angles and emitted from the light output surface 12 of the crystal.

[0073] Among them, since lithium niobate crystal has ~3×10 -5 / ℃ birefringence sensitivity, and only when the principal axis motion period is Λ=λ / |n o -n e Only when the polarization period is equal to that of the periodically poled lithium niobate crystal will the light field be separated into two opposite angles and emitted from the output end of the crystal;

[0074] The laser light source 30 is a tunable laser, and the wavelength of its output light can be adjusted manually. Therefore, it is necessary to adjust the wavelength of the output light of the laser light source 30 so that it conforms to the main axis motion period of Λ = λ / |n o -n e| is equal to the polarization period of the periodically poled lithium niobate crystal. At this time, a CCD 50 is placed behind the periodically poled lithium niobate crystal to take a picture of the output light spot. Since left-handed circular polarization contains both a positive 45-degree linear polarization component and a negative 45-degree linear polarization component, when the input light is polarized as left-handed circular polarization, the output light will be separated into two directions, as shown in Figure 5(a). Similarly, by rotating the angles of the half-wave plate 42 and the quarter-wave plate 43, the polarization state of the light beam is changed to right-handed circular polarization. When the right-handed circularly polarized light is used as the input light, the output light will also be separated into two directions, as shown in Figure 5(b); and when the input light is positive 45-degree linear polarization light or negative 45-degree linear polarization light, their output light is deflected to the left and to the right, respectively, as shown in Figure 5(b). Figure 5(c) and 5(d) shown.

[0075] The second embodiment shows that the optoelectronic adjustable beam splitter provided by the embodiment of the present invention can separate the positive 45-degree linear polarization state and the negative 45-degree linear polarization state.

[0076] In summary, the embodiments of the present invention achieve the separation of light beams of various orthogonal polarization states, and the angle and direction of the separation can be controlled electrically. Compared to traditional beam splitters, the optoelectronically adjustable beam splitter proposed in this embodiment is smaller, has no stringent requirements on the angle of the incident light, can separate any orthogonal polarization state, and can electrically control the angle and direction of the separation of the two orthogonal polarizations in the output light field.

[0077] A second embodiment of the present invention further provides a method for operating the optoelectronically adjustable beam splitter, comprising the following steps:

[0078] Inputting positive 45-degree linear polarized light or negative 45-degree linear polarized light containing a left-handed circular polarization component and a right-handed circular polarization component as the first input light into the light input end of the photoelectric uniaxial crystal;

[0079] A direct current voltage is applied to the first electrode and the second electrode; wherein, under the action of the external electric field, the principal axis of the optoelectronic uniaxial crystal periodically moves along the propagation direction of light, and the transversely varying periodic polarization duty cycle generates an effective magnetic field gradient, which separates the light field into two opposite angles according to the spin angular momentum of the first input light, thereby separating the orthogonal polarization states of left-handed circular polarization and right-handed circular polarization;

[0080] The temperature of the photoelectric uniaxial crystal is adjusted to change the phase difference of the electrodeless area, thereby changing the effective input and output polarization states of the photoelectric uniaxial crystal, so that the photoelectric uniaxial crystal can separate the light field into two opposite angles according to positive 45-degree linear polarization and negative 45-degree linear polarization.

[0081] Preferably, the photoelectric uniaxial crystal is a periodically poled lithium niobate crystal, and the temperature of the photoelectric uniaxial crystal is adjusted by a semiconductor refrigeration plate arranged on the photoelectric uniaxial crystal.

[0082] A third embodiment of the present invention further provides a method for operating the optoelectronically adjustable beam splitter, comprising the following steps:

[0083] Inputting left-handed circularly polarized light or right-handed circularly polarized light containing a positive 45-degree linear polarization component and a negative 45-degree linear polarization component as the second input light into the light input end of the photoelectric uniaxial crystal;

[0084] A DC voltage is applied to the first electrode and the second electrode. Under the action of the external electric field, the main axis of the periodically poled lithium niobate crystal periodically moves along the propagation direction of light. The transversely varying duty cycle of the periodic polarization generates an effective magnetic field gradient, which separates the light field into two opposite angles according to the spin angular momentum of the input light, thereby achieving separation of the orthogonal polarization states of positive 45-degree linear polarization and negative 45-degree linear polarization.

[0085] The embodiments described above are some, but not all, of the embodiments of the present invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are also within the scope of protection of the present invention.

Claims

1. An optoelectronically adjustable beam splitter for separating arbitrary orthogonal polarization states, characterized in that: include: A periodically poled optoelectronic uniaxial crystal having an opposing light input surface and a light output surface; A first electrode is provided on a partial area of ​​the first surface of the photoelectric uniaxial crystal; the area of ​​the first surface close to the light input surface and the light output surface forms an electrode-free area; The second electrode is arranged in a partial area of ​​the second surface of the photoelectric uniaxial crystal opposite to the first surface; the area of ​​the second surface close to the light input surface and the light output surface forms an electrode-free area.

2. The optoelectronically adjustable beam splitter for separating arbitrary orthogonal polarization states according to claim 1, characterized in that: Also includes: A temperature regulating member is configured to regulate the temperature of the photoelectric uniaxial crystal.

3. The optoelectronically adjustable beam splitter for separating arbitrary orthogonal polarization states according to claim 2, characterized in that: The temperature regulating element is a semiconductor refrigeration plate, and the photoelectric uniaxial crystal is arranged on the semiconductor refrigeration plate.

4. The optoelectronically adjustable beam splitter for separating arbitrary orthogonal polarization states according to claim 1, characterized in that: The first electrode and the second electrode are gold films plated on the first surface and the second surface.

5. The optoelectronically adjustable beam splitter for separating arbitrary orthogonal polarization states according to claim 4, characterized in that: The thickness of the gold film is 200 μm.

6. The optoelectronically adjustable beam splitter for separating arbitrary orthogonal polarization states according to claim 1, characterized in that: The photoelectric uniaxial crystal is a periodically poled lithium niobate crystal. Under the action of an external electric field, the principal axis of the photoelectric uniaxial crystal periodically moves along the propagation direction of light.

7. A method for operating an optoelectronically adjustable beam splitter according to any one of claims 1 to 6, characterized in that: The following steps are involved: Inputting positive 45-degree linear polarized light or negative 45-degree linear polarized light containing a left-handed circular polarization component and a right-handed circular polarization component as the first input light into the light input end of the photoelectric uniaxial crystal; A direct current voltage is applied to the first electrode and the second electrode; wherein, under the action of the external electric field, the principal axis of the optoelectronic uniaxial crystal periodically moves along the propagation direction of light, and the transversely varying periodic polarization duty cycle generates an effective magnetic field gradient, which separates the light field into two opposite angles according to the spin angular momentum of the first input light, thereby separating the orthogonal polarization states of left-handed circular polarization and right-handed circular polarization; The temperature of the photoelectric uniaxial crystal is adjusted to change the phase difference of the electrodeless area, thereby changing the effective input and output polarization states of the photoelectric uniaxial crystal, so that the photoelectric uniaxial crystal can separate the light field into two opposite angles according to positive 45-degree linear polarization and negative 45-degree linear polarization.

8. The working method according to claim 7, characterized in that: The photoelectric uniaxial crystal is a periodically poled lithium niobate crystal, and the temperature of the photoelectric uniaxial crystal is adjusted by a semiconductor refrigeration plate arranged on the photoelectric uniaxial crystal.

9. A method for operating an optoelectronically adjustable beam splitter according to any one of claims 1 to 6, characterized in that: The following steps are involved: Inputting left-handed circularly polarized light or right-handed circularly polarized light containing a positive 45-degree linear polarization component and a negative 45-degree linear polarization component as the second input light into the light input end of the photoelectric uniaxial crystal; A DC voltage is applied to the first electrode and the second electrode. Under the action of the external electric field, the main axis of the periodically poled lithium niobate crystal periodically moves along the propagation direction of light. The transversely varying duty cycle of the periodic polarization generates an effective magnetic field gradient, which separates the light field into two opposite angles according to the spin angular momentum of the input light, thereby achieving separation of the orthogonal polarization states of positive 45-degree linear polarization and negative 45-degree linear polarization.

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