Polarization beam splitting device with titanium dioxide-quartz composite structure and preparation method thereof

Abstract

The application discloses a polarization beam splitting device with a titanium dioxide quartz composite structure and a preparation method, and relates to the technical field of beam splitting devices. The polarization beam splitting device with the titanium dioxide quartz composite structure comprises a quartz substrate, a transition metal layer and a titanium dioxide structure group which are sequentially stacked from bottom to top, and the titanium dioxide structure group comprises a plurality of microstructure units with different beam splitting directions. Compared with a traditional polarization beam splitting device, the polarization beam splitting device of the embodiment of the application divides the polarization element into several regions, different regions have different directional polarization responses to incident light, and finally the required polarization beam splitting effect is obtained at a far-field target position. The laser beam can be split into multiple beams, the period limitation of the diffraction formula is broken, specific polarization beam splitting based on incident polarization can be realized, the beam is diffracted into discrete orders based on a similar grating phase structure, which is different from the traditional beam splitting, and has better beam splitting effect.

Description

Technical Field

[0001] This invention relates to the field of beam splitting device technology, and in particular to a polarization beam splitting device with a titanium dioxide-quartz composite structure and its preparation method. Background Technology

[0002] In traditional beam splitting methods, light is divided into two beams: a reflected beam and a transferred beam. Traditional beam splitters are based on the principle of reflection, where part of the beam is reflected while the rest continues along its original trajectory. Due to structural limitations, this method can only achieve beam splitting in one direction at a time, resulting in poor beam splitting performance. Summary of the Invention

[0003] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes a polarization beam splitter device with a titanium dioxide-quartz composite structure and its preparation method, which has a better beam splitting effect.

[0004] On one hand, the polarization beam splitter of the titanium dioxide-quartz composite structure according to an embodiment of the present invention includes a quartz substrate, a transition metal layer and a titanium dioxide structure group stacked sequentially from bottom to top, wherein the titanium dioxide structure group includes multiple microstructure units with different beam splitting directions.

[0005] According to some embodiments of the present invention, the polarization beam splitter of the titanium dioxide-quartz composite structure further includes an antireflection film disposed on the surface of the titanium dioxide structure assembly.

[0006] According to some embodiments of the present invention, the titanium dioxide structure group includes four microstructure units, namely a first microstructure unit, a second microstructure unit, a third microstructure unit, and a fourth microstructure unit. Each microstructure unit includes a plurality of rectangular pillars. The plurality of rectangular pillars of the first microstructure unit are arranged in a diagonal symmetrical manner, the plurality of rectangular pillars of the second microstructure unit are arranged in a left-right symmetrical manner, the plurality of rectangular pillars of the third microstructure unit are arranged in a right-side symmetrical manner, and the plurality of rectangular pillars of the fourth microstructure unit are arranged in a top-bottom symmetrical manner.

[0007] According to some embodiments of the present invention, the linewidth variation of the first microstructure unit and the third microstructure unit is 2.3 μm, and the beam splitting angle is 16 degrees; the linewidth variation of the second microstructure unit and the fourth microstructure unit is 3.2 μm, and the beam splitting angle is 12 degrees.

[0008] According to some embodiments of the present invention, when linearly polarized light is incident on the polarization beam splitter of the titanium dioxide-quartz composite structure, the titanium dioxide structure group splits the linearly polarized light into two circularly polarized beams through structural arrangement and modulates them respectively, resulting in a centrally symmetrical conjugate circularly polarized mode output light spot.

[0009] According to some embodiments of the present invention, the polarization beam splitter of the titanium dioxide-quartz composite structure modulates a left-handed circularly polarized incident beam into a right-handed circularly polarized outgoing beam, or modulates a right-handed circularly polarized incident beam into a left-handed circularly polarized outgoing beam, by setting a rotation angle. The polarization effect caused by the different phase responses of the circularly polarized beams is centrally symmetrical.

[0010] According to some embodiments of the present invention, the transition metal layer is a chromium layer.

[0011] According to some embodiments of the present invention, the height, period, and rotation angle of the titanium dioxide structure group are adjusted according to the reference light wavelength to form a periodic phase grating to guide the beam splitting angle of the light.

[0012] On the other hand, the method for fabricating a polarization beam splitter according to an embodiment of the present invention includes the following steps:

[0013] Obtain a quartz substrate;

[0014] A transition metal layer is deposited on the surface of the quartz substrate;

[0015] Titanium dioxide is deposited on the surface of the transition metal layer to form a substrate;

[0016] Generate a BMP file according to the design requirements, and import it into the EBL file for recognition;

[0017] Based on the identification results, the substrate is etched to form a titanium dioxide structure group, which includes multiple microstructure units with different beam splitting directions.

[0018] According to some embodiments of the present invention, the method further includes the following steps:

[0019] An antireflective coating is disposed on the surface of the titanium dioxide structure group.

[0020] The polarization beam splitter device and its fabrication method based on the titanium dioxide-quartz composite structure according to embodiments of the present invention have at least the following beneficial effects: Based on the composite structure of titanium dioxide and quartz, the high transmission and low absorption characteristics of the titanium dioxide structure group in the visible light band are utilized to guide the direction of light by inducing local phase changes, thereby achieving beam splitting. Compared with traditional polarization beam splitters, the polarization beam splitter device of the present invention proposes to divide the polarization element into several regions, with different regions having different polarization responses to incident light, ultimately obtaining the desired polarization beam splitting effect at the far-field target position. It can split the laser beam into multiple beams, breaking the periodic limitation of the diffraction formula, and can achieve specific polarization beam splitting based on incident polarization. Based on a grating-like phase structure, the beam is diffracted into discrete orders, which is different from traditional beam splitting. This polarization beam splitter device has a simple structure, is compatible with CMOS technology, is easy to process, and can be used in the fields of smart interconnection and virtual reality.

[0021] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0022] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0023] Figure 1 This is a schematic diagram of the polarization beam splitter device with a titanium dioxide-quartz composite structure according to an embodiment of the present invention;

[0024] Figure 2 This is a cross-sectional schematic diagram of the titanium dioxide structure assembly according to an embodiment of the present invention;

[0025] Figure 3 This is a three-dimensional schematic diagram of a 3*3 polarization beam splitter with a titanium dioxide-quartz composite structure according to an embodiment of the present invention.

[0026] Figure 4 This is a schematic diagram of the rectangular ring polarization beam splitter with a titanium dioxide-quartz composite structure according to an embodiment of the present invention.

[0027] Figure 5 This is a two-dimensional far-field intensity distribution diagram of a 3*3 polarization beam splitter with a titanium dioxide-quartz composite structure according to an embodiment of the present invention.

[0028] Figure 6 This is a three-dimensional far-field intensity distribution diagram of a 3*3 polarization beam splitter with a titanium dioxide-quartz composite structure according to an embodiment of the present invention.

[0029] Figure 7 This is a two-dimensional far-field intensity distribution diagram of a rectangular ring-shaped polarization beam splitter with a titanium dioxide-quartz composite structure according to an embodiment of the present invention.

[0030] Figure 8 This is a three-dimensional far-field intensity distribution diagram of a rectangular ring-shaped polarization beam splitter with a titanium dioxide-quartz composite structure according to an embodiment of the present invention.

[0031] Figure 9 This is a flowchart illustrating the steps of a method for fabricating a polarization beam splitter according to an embodiment of the present invention.

[0032] Figure label:

[0033] Quartz substrate 2.1, transition metal layer 2.2, titanium dioxide structure group 2.3, first microstructure unit 1.1, second microstructure unit 1.2, third microstructure unit 1.3, fourth microstructure unit 1.4. Detailed Implementation

[0034] The embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. The step numbers in the following embodiments are set only for ease of explanation, and there is no limitation on the order between the steps. The execution order of each step in the embodiments can be adaptively adjusted according to the understanding of those skilled in the art.

[0035] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0036] The terms "first," "second," "third," and "fourth," etc., used in the specification, claims, and accompanying drawings of this invention are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0037] In this invention, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0038] In traditional beam splitting methods, light is divided into two beams: a reflected beam and a transferred beam. Traditional beam splitters are based on the principle of reflection, where part of the beam is reflected while the rest continues along its original trajectory. Due to structural limitations, this method can only achieve beam splitting in one direction at a time, resulting in poor beam splitting performance.

[0039] To address this, this invention provides a polarization beam splitter device and its fabrication method based on a titanium dioxide-quartz composite structure. Utilizing the high transmission and low absorption characteristics of the titanium dioxide structure in the visible light band, the device forms arrow-shaped and arc-shaped scale-like high aspect ratio structures through periodic microstructure unit arrangement. This induces local phase changes, guiding the light beam and achieving beam splitting. Compared to traditional polarization beam splitters, this invention divides the polarization element into several regions. Different regions respond to incident light with different polarization directions, ultimately achieving the desired polarization beam splitting effect at the far-field target location. This splits the laser beam into multiple beams, breaking the periodic limitation of the diffraction formula and enabling specific polarization beam splitting based on incident polarization. Based on a grating-like phase structure, the beam is diffracted into discrete orders, unlike traditional beam splitting methods. Simultaneously, it can split a linearly polarized beam into two conjugate circularly polarized beams, with the far-field effect of the conjugate circular polarization exhibiting central symmetry. This polarization beam splitter has a simple structure, is compatible with CMOS technology, and is easy to fabricate, making it suitable for applications in smart interconnection and virtual reality. Furthermore, the polarization beam splitter of this embodiment combines periodic structural coupling behavior with the scattering modulation characteristics of metaatoms in the metasurface. The metasurface derived from the subwavelength grating can utilize periodic Bragg scattering to improve the efficiency of beam control, thereby avoiding the efficiency reduction and energy loss caused by phase discretization of the metasurface. Titanium dioxide can be used as a highly effective birefringent material in the visible light band, is compatible with traditional CMOS technology, and features easy fabrication, simple structure, and high reproducibility. Compared to the plasmon resonance method using noble metals, it is more suitable for mass production and offers higher economic benefits.

[0040] The following is in conjunction with the appendix Figure 1-9 This invention provides a detailed description of the polarization beam splitter device and its preparation method based on the titanium dioxide-quartz composite structure of the present invention.

[0041] On the one hand, embodiments of the present invention propose a polarization beam splitter with a titanium dioxide-quartz composite structure, such as... Figure 1 As shown, the polarization beam splitter includes a quartz substrate 2.1, a transition metal layer 2.2, and a titanium dioxide structure group 2.3, which are stacked sequentially from bottom to top. Figure 2 As shown, the titanium dioxide structure group 2.3 includes multiple microstructure units (1.1-1.4) with different beam splitting directions. Among them, the titanium dioxide structure group 2.3 is in the form of scales with a high aspect ratio. Except for the bottom quartz substrate 2.1, the thickness of the remaining structures needs to be controlled. The whole structure is a layered structure from bottom to top to achieve the far-field beam splitting effect of linearly polarized beams of specific wavelengths.

[0042] Furthermore, in some embodiments of the present invention, the polarization beam splitter device with a titanium dioxide-quartz composite structure further includes an antireflection film (not shown) disposed on the surface of the titanium dioxide structure group 2.3. The antireflection film is added as appropriate according to the processing of the device, and the antireflection film can enhance the light transmittance of the device and reduce or eliminate stray light.

[0043] Furthermore, such as Figure 2 As shown, in some embodiments of the present invention, the titanium dioxide structure group 2.3 includes four microstructure units, namely a first microstructure unit 1.1, a second microstructure unit 1.2, a third microstructure unit 1.3, and a fourth microstructure unit 1.4. Each microstructure unit includes multiple rectangular pillars. The rectangular pillars of the first microstructure unit 1.1 are arranged symmetrically along the diagonal, the rectangular pillars of the second microstructure unit 1.2 are arranged symmetrically from left to right, the rectangular pillars of the third microstructure unit 1.3 are arranged symmetrically along the anti-diagonal, and the rectangular pillars of the fourth microstructure unit 1.4 are arranged symmetrically from top to bottom. The titanium dioxide structure group 2.3 is divided into four regions according to the far-field beam splitting effect, which are used for beam splitting along the diagonal, along the Y-axis, along the anti-diagonal, and along the X-axis, respectively. The four microstructure units function independently and do not interfere with each other. Each microstructure unit is composed of an array of multiple rectangular pillars with a high aspect ratio. Each rectangular pillar has the same length, width, and height structure and is arranged periodically.

[0044] In this example, when linearly polarized light is incident on the polarization beam splitter of the titanium dioxide-quartz composite structure, the titanium dioxide structure group 2.3 splits the linearly polarized light into two circularly polarized beams through structural arrangement and modulates them separately, resulting in a centrally symmetrical conjugate circularly polarized mode output light spot.

[0045] In this example, the titanium dioxide-quartz composite polarization beam splitter modulates a left-handed circularly polarized incident beam into a right-handed circularly polarized outgoing beam by setting a rotation angle, or modulates a right-handed circularly polarized incident beam into a left-handed circularly polarized outgoing beam. The polarization effect caused by the different phase responses of the circularly polarized beams is centrally symmetrical.

[0046] In this example, the transition metal layer 2.2 is a chromium layer with a thickness of approximately 5 nm. Its function is to serve as a connecting layer between the quartz substrate 2.1 and the titanium dioxide structure group 2.3, and to enhance the conductivity.

[0047] In this example, the height, period, and rotation angle of the titanium dioxide structure group 2.3 are adjusted according to the reference light wavelength. Its function is to form a periodic phase grating through the action of electric and magnetic dipoles, guiding the beam splitting angle of the light.

[0048] Example 1:

[0049] The following describes the fabrication process of a 3x3 polarization beam splitter with a titanium dioxide-quartz composite structure as an example: First, the quartz substrate 2.1 is processed by depositing a 5nm layer of chromium onto a molten quartz sheet. Then, titanium dioxide is deposited on the chromium layer using a deposition method, followed by homogenization to create a substrate ready for processing. Next, a BMP file (a graphic file format) is generated based on design requirements, imported into EBL (e-beam lithography) for identification, and the corresponding substrate is loaded, aligned, and then subjected to plasma etching. The final fabricated 3x3 polarization beam splitter with a titanium dioxide-quartz composite structure is shown below. Figure 3 As shown, under an incident light intensity of 632 nm, the microstructure unit of titanium dioxide structure group 2.3 has a period of 400 nm, a unit length and width of 130 nm * 300 nm, a unit height of 600 nm, and a rotation angle determined by the phase. The unit transmittance is over 90%. Specifically, the linewidth variation of the first microstructure unit 1.1 and the third microstructure unit 1.3 is 2.3 μm, with a beam splitting angle of approximately 16 degrees; the linewidth variation of the second microstructure unit 1.2 and the fourth microstructure unit 1.4 is 3.2 μm, with a beam splitting angle of approximately 12 degrees; the central zero order consists of crosstalk and unmodulated portions from the four microstructure units. The two-dimensional far-field intensity distribution of this device is shown in the figure. Figure 5 As shown, the three-dimensional far-field intensity distribution map is as follows: Figure 6 As shown, the two-dimensional far-field intensity distribution diagram reflects the modulation effect of the polarization beam splitter on the beam. The calculated total diffraction efficiency in the far field is 75.5%, with the same relative order diffraction efficiency and a total uniformity error of 11.7%. It can be seen that the obtained polarization beam splitter has a good beam splitting effect at the predetermined beam splitting angle and a high diffraction efficiency, which has application value.

[0050] Example 2:

[0051] The following describes the fabrication process of a rectangular ring-shaped polarization beam splitter with a titanium dioxide-quartz composite structure as an example: First, the quartz substrate 2.1 is processed. A 5nm layer of chromium is deposited on the fused quartz sheet. Then, titanium dioxide is deposited on the chromium layer using a deposition method, followed by homogenization to create a substrate ready for processing. Next, a BMP file is generated based on design requirements, imported into EBL for identification, and the corresponding substrate is loaded, aligned, and etched. The final fabricated rectangular ring-shaped polarization beam splitter with a titanium dioxide-quartz composite structure is shown below. Figure 4 As shown, the microstructure unit is determined by the wavelength. Under an incident light condition of 632 nm, the unit period is 400 nm, the unit size is 130 nm * 300 nm, the unit height is 600 nm, the rotation angle is determined by the phase, and the unit transmittance is over 90%. Figure 4 As shown, the linewidth variation of the first microstructure unit 1.1 and the third microstructure unit 1.3 is 2.3 μm, and the beam splitting angle is approximately 16 degrees; the linewidth variation of the second microstructure unit 1.2 and the fourth microstructure unit 1.4 is 3.2 μm, and the beam splitting angle is approximately 12 degrees. The two-dimensional far-field intensity distribution of this device is shown in the figure. Figure 7 As shown, the three-dimensional far-field intensity distribution map is as follows: Figure 8 As shown, the two-dimensional far-field intensity distribution diagram reflects the modulation effect of the polarization beam splitter on the beam. The calculated total diffraction efficiency in the far field is 75.9%, with the same relative order diffraction efficiency and a total uniformity error of 8.2%. It can be seen that the obtained polarization element has a good beam splitting effect at the predetermined beam splitting angle and a high diffraction efficiency, which has application value.

[0052] The polarization beam splitter of the present invention, based on a titanium dioxide-quartz composite structure, utilizes the high transmission and low absorption characteristics of the titanium dioxide structure group 2.3 in the visible light band. Through the periodic arrangement of microstructure units, arrow-shaped and arc-shaped scale-like high aspect ratio structure groups are formed. By inducing local phase changes, the beam direction is guided, achieving beam splitting. Compared with traditional polarization beam splitters, the polarization element of this invention is divided into several regions. Different regions have different polarization responses to incident light, ultimately achieving the desired polarization beam splitting effect at the far-field target position. This splits the laser beam into multiple beams, breaking the periodic limitation of the diffraction formula. It can achieve specific polarization beam splitting based on incident polarization. Based on a grating-like phase structure, the beam is diffracted into discrete orders, which differs from traditional beam splitting. Simultaneously, it can split a linearly polarized beam into two conjugate circularly polarized beams, with the far-field effect of the conjugate circular polarization exhibiting central symmetry. This polarization beam splitter has a simple structure, is compatible with CMOS technology, and is easy to fabricate, making it suitable for applications in smart interconnection and virtual reality. Furthermore, the polarization beam splitter of this embodiment combines periodic structural coupling behavior with the scattering modulation characteristics of metaatoms in the metasurface. The metasurface derived from the subwavelength grating can utilize periodic Bragg scattering to improve the efficiency of beam control, thereby avoiding the efficiency reduction and energy loss caused by phase discretization of the metasurface. Titanium dioxide can be used as a highly effective birefringent material in the visible light band, is compatible with traditional CMOS technology, and features easy fabrication, simple structure, and high reproducibility. Compared to the plasmon resonance method using noble metals, it is more suitable for mass production and offers higher economic benefits.

[0053] On the other hand, such as Figure 9 As shown, based on the above-mentioned titanium dioxide-quartz composite structure polarization beam splitter, this embodiment of the invention also proposes a method for fabricating the polarization beam splitter, which includes the following steps:

[0054] Step S100: Obtain the quartz substrate 2.1;

[0055] Step S200: Deposit a transition metal layer 2.2 onto the surface of the quartz substrate 2.1;

[0056] Step S300: Deposit titanium dioxide on the surface of the transition metal layer 2.2 to form a substrate;

[0057] Step S400: Generate a BMP file according to the design requirements and import it into the EBL file for recognition;

[0058] Step S500: Based on the identification results, the substrate is etched to form a titanium dioxide structure group 2.3.

[0059] First, the quartz substrate 2.1 is processed by depositing a 5nm chromium layer on a fused quartz sheet. Then, titanium dioxide is deposited on the chromium layer using a deposition method, followed by homogenization to create a substrate ready for processing. Next, a BMP file is generated based on the design, imported into EBL for identification, and the corresponding substrate is loaded, aligned, and subjected to plasma etching to finally fabricate a polarization beam splitter device with a titanium dioxide-quartz composite structure.

[0060] Furthermore, an antireflective film can be provided on the surface of the titanium dioxide structure group 2.3 to enhance the light transmittance of the device and reduce or eliminate stray light.

[0061] It should be noted that the content of the above embodiments is applicable to the present method embodiments. The specific functions implemented in the present method embodiments are the same as those in the above embodiments, and the beneficial effects achieved are also the same as those achieved in the above embodiments.

[0062] The polarization beam splitter fabricated by the method according to an embodiment of the present invention is based on a composite structure of titanium dioxide and quartz. Utilizing the high transmission and low absorption characteristics of the titanium dioxide structure group 2.3 in the visible light band, it forms arrow-shaped and arc-shaped scale-like high aspect ratio structure groups through periodic microstructure unit arrangement. By inducing local phase changes, it guides the direction of light, thereby achieving beam splitting. Compared with traditional polarization beam splitters, the polarization beam splitter of this embodiment proposes to divide the polarization element into several regions. Different regions have different polarization responses to incident light, ultimately obtaining the desired polarization beam splitting effect at the far-field target position. It can split the laser beam into multiple beams, breaking the periodic limitation of the diffraction formula, and can achieve specific polarization beam splitting based on incident polarization. Based on a grating-like phase structure, it diffracts the beam into discrete orders, which differs from traditional beam splitting. Simultaneously, it can split a linearly polarized beam into two conjugate circularly polarized beams, with the far-field effect of the conjugate circular polarization exhibiting central symmetry. This polarization beam splitter has a simple structure, is compatible with CMOS technology, and is easy to fabricate, making it suitable for applications in smart interconnection and virtual reality. Furthermore, the polarization beam splitter of this embodiment combines periodic structural coupling behavior with the scattering modulation characteristics of metaatoms in the metasurface. The metasurface derived from the subwavelength grating can utilize periodic Bragg scattering to improve the efficiency of beam control, thereby avoiding the efficiency reduction and energy loss caused by phase discretization of the metasurface. Titanium dioxide can be used as a highly effective birefringent material in the visible light band, is compatible with traditional CMOS technology, and features easy fabrication, simple structure, and high reproducibility. Compared to the plasmon resonance method using noble metals, it is more suitable for mass production and offers higher economic benefits.

[0063] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A polarization splitting device of a titanium dioxide-silicon composite structure, characterized by, The quartz substrate, the transition metal layer and the titanium dioxide structure group are sequentially stacked from bottom to top, the titanium dioxide structure group includes a plurality of microstructure units with different beam splitting directions, the titanium dioxide structure group includes four microstructure units, namely a first microstructure unit, a second microstructure unit, a third microstructure unit and a fourth microstructure unit, each microstructure unit includes a plurality of rectangular columns, the plurality of rectangular columns of the first microstructure unit are arranged in a diagonal symmetry form, the plurality of rectangular columns of the second microstructure unit are arranged in a left-right symmetry form, the plurality of rectangular columns of the third microstructure unit are arranged in an anti-diagonal symmetry form, and the plurality of rectangular columns of the fourth microstructure unit are arranged in an up-down symmetry form, the polarization beam splitting device of the titanium dioxide quartz composite structure modulates the left circularly polarized incident light beam into a right circularly polarized outgoing light beam or modulates the right circularly polarized incident light beam into a left circularly polarized outgoing light beam by setting a rotation angle, and the polarization effects caused by different phase responses of mutually different circular polarizations are center-symmetric, and each rectangular column of each microstructure unit has the same length-width-height structure.

2. The titanium dioxide-quartz composite polarizing beam splitting device according to claim 1, wherein The polarization beam splitting device of the titanium dioxide quartz composite structure further includes an anti-reflection film arranged on the surface of the titanium dioxide structure group.

3. The titanium dioxide-silicon compound structure polarizing beam splitting device according to claim 1, wherein The line width variable of the first microstructure unit and the third microstructure unit is 2.3 um, and the beam splitting angle is 16 degrees; the line width variable of the second microstructure unit and the fourth microstructure unit is 3.2 um, and the beam splitting angle is 12 degrees.

4. The titanium dioxide-silicon compound structure polarizing beam splitting device according to claim 1, wherein When linearly polarized light is incident on the polarization beam splitting device of the titanium dioxide quartz composite structure, the titanium dioxide structure group splits the linearly polarized light into two circularly polarized lights by structural arrangement, and the resulting conjugate circularly polarized mode outgoing light spot is center-symmetric.

5. The titanium dioxide-silicon compound structure polarizing beam splitting device according to claim 1, wherein The transition metal layer is a chromium layer.

6. The titanium dioxide-silicon compound structure polarizing beam splitting device according to claim 1, wherein The height, period and rotation angle of the titanium dioxide structure group are adjusted according to the reference light wavelength to form a periodic phase grating to guide the beam splitting angle of light.

7. A method for producing a polarization splitting device, characterized by The method comprises the following steps: obtaining a quartz substrate; plating a transition metal layer on the surface of the quartz substrate; depositing titanium dioxide on the surface of the transition metal layer to form a substrate; generating a BMP file according to design requirements and importing EBL for identification; According to the identification result, the substrate is etched to form a titanium dioxide structure group, the titanium dioxide structure group includes four microstructure units with different beam splitting directions, which are a first microstructure unit, a second microstructure unit, a third microstructure unit and a fourth microstructure unit, each of the microstructure units includes a plurality of rectangular columns, the plurality of rectangular columns of the first microstructure unit are arranged in a diagonal symmetry form, the plurality of rectangular columns of the second microstructure unit are arranged in a left-right symmetry form, the plurality of rectangular columns of the third microstructure unit are arranged in an anti-diagonal symmetry form, and the plurality of rectangular columns of the fourth microstructure unit are arranged in an up-down symmetry form; the polarization beam splitting device modulates a left circularly polarized incident light beam into a right circularly polarized outgoing light beam or modulates a right circularly polarized incident light beam into a left circularly polarized outgoing light beam by setting a rotation angle, and the polarization effects caused by different phase responses of mutually different circular polarizations are center-symmetric; each of the rectangular columns of each of the microstructure units has the same length-width-height structure.

8. The method of producing a polarization splitting device according to claim 7, characterized in that Further comprising the following steps: A antireflection film is arranged on the surface of the titanium dioxide structure group.

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