Polarization controller and optical device

Abstract

The invention provides a polarization controller and an optical device, and relates to the technical field of optics, the polarization controller comprises a metal substrate layer, a nanowire and an oxide dielectric layer; the oxide dielectric layer is arranged above the metal substrate layer; the nanowire extends along a straight line, the nanowire is arranged in the oxide dielectric layer, and the nanowire is parallel to the metal substrate layer; one end of the nanowire is an incident end of non-polarized light, and a gap between the other end of the nanowire and the metal substrate layer is an emergent end of polarized light. According to the polarization controller and the optical device provided by the invention, precise constraint on a light field on a nanoscale can be realized, light field limitation of diffraction limit is broken through, regulation and control on a nanoscale light wave polarization state are realized, meanwhile, due to the requirement of plasmon polaritons of the metal substrate layer on a polarization mode, the polarization controller can realize TM polarization, and the polarization degree is improved. And the specific requirements of different application fields on the light polarization state can be met, and the application prospect is wide.

Description

Technical Field

[0001] The present invention relates to the field of optical technology, and in particular to a polarization controller and an optical device. Background Art

[0002] Polarization controller is an optical device used to control the polarization state of light waves. It is widely used in optical communications, optical sensing, laser technology and other fields. The core function of polarization controller is to accurately adjust the polarization state of input light to meet specific application requirements.

[0003] Polarization controllers based on surface plasmons can achieve more precise polarization control in a smaller size and are suitable for complex optical systems and high-end applications, especially in the fields of micro-nano optics and integrated optics.

[0004] However, the traditional surface plasmon-based polarization controller in the related art is affected by the diffraction limit, and it is difficult to achieve precise constraints on the light field at the nanoscale, and thus it is difficult to achieve the regulation of the polarization state of light waves at the nanoscale. Therefore, how to achieve precise constraints on the light field at the nanoscale, so as to achieve the regulation of the polarization state of light waves at the nanoscale, is a technical problem that needs to be solved in this field. Summary of the invention

[0005] The present invention provides a polarization controller and an optical device, which are used to solve the defect that the traditional polarization controller in the prior art is difficult to achieve precise constraint of the light field at the nanometer scale, and thus difficult to achieve regulation of the polarization state of the light wave at the nanometer scale, and achieve precise constraint of the light field at the nanometer scale, thereby achieving regulation of the polarization state of the light wave at the nanometer scale.

[0006] The present invention provides a polarization controller, comprising: a metal substrate layer, a nanowire and an oxide dielectric layer; The oxide dielectric layer is disposed above the metal substrate layer; the nanowires extend in a straight line, are disposed inside the oxide dielectric layer, and are parallel to the metal substrate layer; One end of the nanowire is the incident end of non-polarized light, and the gap between the other end of the nanowire and the metal substrate layer is the emitting end of polarized light.

[0007] According to a polarization controller provided by the present invention, the material of the metal substrate is selected from one or more of gold, silver, aluminum, copper and indium.

[0008] According to a polarization controller provided by the present invention, the material of the oxide dielectric layer is silicon dioxide.

[0009] According to a polarization controller provided by the present invention, the material of the nanowire is silicon.

[0010] According to a polarization controller provided by the present invention, the distance between the nanowire and the target interface is no more than 25 nanometers, and the target interface is the interface between the metal substrate layer and the oxide dielectric layer.

[0011] According to a polarization controller provided by the present invention, the cross-section of the nanowire is circular, and the diameter of the nanowire is 100 to 300 nanometers.

[0012] According to a polarization controller provided by the present invention, the distance between the nanowire and the target interface is 2 to 5 nanometers.

[0013] According to a polarization controller provided by the present invention, the polarization controller operates in a transverse magnetic mode (TM).

[0014] According to a polarization controller provided by the present invention, the wavelength range of the unpolarized light is 800 to 1600 nanometers.

[0015] The present invention also provides an optical device, comprising any polarization controller as described above.

[0016] The polarization controller, optical device and optical system provided by the present invention include a metal substrate layer, a nanowire and an oxide medium layer, wherein the oxide medium layer is arranged above the metal substrate layer, the nanowire extends in a straight line, the nanowire is arranged inside the oxide medium layer, the nanowire is parallel to the metal substrate layer, one end of the nanowire is the incident end of non-polarized light, and the gap between the other end of the nanowire and the metal substrate layer is the exit end of polarized light. The polarization controller has a simple structure and is easy to manufacture. By forming a low-refractive index gap between the nanowire and the metal medium layer, the focusing and polarization functions can be realized at the nanoscale. Due to the discontinuity of the electric field at the interface between the low-refractive index gap and the high-refractive index nanowire, the light field in the low-refractive index gap between the nanowire and the metal substrate layer is enhanced and coupled with the plasma wave on the surface of the metal substrate layer, so that the light field can be precisely constrained at the nanoscale, the light field limitation of the diffraction limit is broken, and the polarization state of the light wave at the nanoscale is regulated. At the same time, due to the requirements of the plasma excitons of the metal substrate layer on the polarization mode, TM polarization can be realized, and the application prospect is broad. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 This is one of the structural schematic diagrams of the polarization controller provided by the present invention.

[0019] Figure 2 This is the second structural schematic diagram of the polarization controller provided by the present invention.

[0020] Figure 3 This is the electric field distribution diagram of the polarization controller provided by the present invention in the TM mode.

[0021] Figure 4 This is the electric field distribution diagram of the polarization controller provided by the present invention in the TE mode.

[0022] Figure 5 It is a correlation diagram between the metal substrates of different materials and the extinction ratio and transmission loss of the polarization controller provided by the present invention.

[0023] Figure 6 It is a correlation diagram between the diameter of the nanowire and the effective mode field area in the polarization controller provided by the present invention. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are 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 creative work are within the scope of protection of the present invention.

[0025] In the description of the invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] In the description of the present application, the terms "first", "second", etc. are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are usually a class, and the number of objects is not limited. For example, the first object can be one or more. In addition, in the description of the present application, "and / or" represents at least one of the connected objects, and the character " / " generally represents that the front and back associated objects are in an "or" relationship.

[0027] It should be noted that the diffraction limit is a fundamental limitation of optical systems and usually represents the minimum spatial resolution that can be achieved by optical devices such as optical microscopes, imaging systems or optical waveguides.

[0028] Traditional optical devices are affected by the diffraction limit, and their lateral dimensions are limited to the micrometer scale. It is difficult to effectively detect or operate optical features smaller than this scale, which makes it difficult to integrate traditional optical devices with nanoscale electronic devices, seriously hindering the development of integrated photonics. Therefore, how to break through the diffraction limit of traditional optical devices and achieve sub-wavelength-scale beam control is one of the core technical challenges in the field of optical technology.

[0029] Surface plasmon is a wave phenomenon formed by the interaction between light and free electrons on the metal surface. Surface plasmon can constrain the light field to a scale much smaller than the wavelength of light. By designing nanostructures, such as metal nanoholes and metal nanowires, surface plasmon can excite local strong light fields on a sub-wavelength scale, thus breaking through the diffraction limit of traditional optical devices.

[0030] Optical systems such as coherent optical communications and optical sensing systems rely heavily on the polarization state of light. Therefore, polarization controllers used to regulate the polarization state of light waves are widely used in optical communications, optical sensing, laser technology and other fields.

[0031] Compared with traditional polarizers, surface plasmon-based polarization controllers can achieve more precise polarization control in a smaller size, and are suitable for complex optical systems and high-end applications, especially in the fields of micro-nano optics and integrated optics. Traditional polarizers are more suitable for simple, low-cost polarization control, and are usually used in general optical experiments and communication systems.

[0032] The traditional surface plasmon-based polarization controller in the related technology includes an ultra-compact, low-loss TE polarization controller using a hybrid plasma ridge waveguide structure. The traditional surface plasmon-based polarization controller is more focused on improving the polarization effect rather than the nanoscale polarization control constraints of the light field. The experiment reduces the loss by shortening the device length. The numerical simulation results show that at a wavelength of 1550nm, 4.2 The long polarization controller has an extinction ratio of 29.5dB, an insertion loss of 0.18dB, and an extinction ratio of more than 23dB within a 100nm bandwidth.

[0033] The conventional surface plasmon-based polarization controller in the related art can also include a nanoscale TM polarization controller based on TE polarization plasma absorption integrated on a silicon waveguide through a periodic metal nanoparticle chain. Experimental results show that at 1.59 wavelength, the extinction ratio of the polarization controller is 23dB / , insertion loss is 2.4dB / .

[0034] The conventional surface plasmon-based polarization controller in the related art may also include a low-loss hybrid plasma TM polarization controller based on polarization mode conversion using a silicon hybrid plasma slot waveguide (HPSW). The polarization controller uses a silicon hybrid plasma slot waveguide (HPSW) to convert the TE fundamental mode into a TM high-order mode and suppress the TE mode while retaining the TM fundamental mode. The device has an insertion loss as low as 0.4 dB and an extinction ratio of 28.3 dB at 1550 nm.

[0035] The traditional surface plasmon-based polarization controllers in the related technologies mainly focus on improving the extinction ratio and reducing the insertion loss. The above-mentioned traditional surface plasmon-based polarization controllers are difficult to achieve precise constraints on the light field at the nanoscale, and thus it is difficult to control the polarization state of nanoscale light waves, resulting in the difficulty in integrating the polarization controller with nanoscale electronic devices, which restricts the miniaturization of optical systems and the development of high-density photonic integration technology.

[0036] Figure 1 This is one of the structural schematic diagrams of the polarization controller provided by the present invention. Figure 2 This is the second schematic diagram of the structure of the polarization controller provided by the present invention. Figure 1 and Figure 2 The polarization controller provided by the present invention is described. Figure 1 and Figure 2 As shown, the polarization controller 101 includes: a metal substrate layer 102 , nanowires 103 and an oxide dielectric layer 104 .

[0037] The oxide dielectric layer 104 is disposed above the metal substrate layer 102 ; the nanowire 103 extends in a straight line, the nanowire 103 is disposed inside the oxide dielectric layer 104 , and the nanowire 103 is parallel to the metal substrate layer 102 .

[0038] One end of the nanowire 103 is the incident end of non-polarized light, and the gap between the other end of the nanowire 103 and the metal substrate layer 102 is the emitting end of polarized light.

[0039] It should be noted that the polarization controller 101 supports a new hybrid plasma TM mode and satisfies the TE mode cutoff condition at the same time.

[0040] Based on Maxwell's equations, the normal component of the electric displacement vector is continuous on the boundary. Therefore, when the diameter of the nanowire 103 continues to decrease, the light field will leak from the high refractive index nanowire 103 to the low emissivity oxide medium layer 104, and the normal component of the electric field intensity will have a significant jump.

[0041] A low-refractive index gap composed of an oxide dielectric layer 104 is formed between the metal substrate layer 102 and the nanowires 103. The light field entering the low-refractive index gap will couple with the plasmons on the surface of the metal substrate layer 102, so that a new hybrid plasma TM mode appears in the low-refractive index gap. This mode no longer shows the characteristics of the TM waveguide mode and the SPP mode, but realizes capacitive energy storage through a low dielectric constant film, confines the light energy in the nanoscale dielectric film, and enables the hybrid TM mode to achieve low-loss long-range transmission in the low dielectric constant region. The mode field of this hybrid mode can be strictly constrained within a range far smaller than the wavelength, achieving light field confinement that breaks through the diffraction limit.

[0042] In the embodiment of the present invention, the interface between the metal substrate layer 102 and the oxide medium layer 104 can be determined as the target interface. By adjusting the diameter of the nanowire 103 and the distance between the nanowire 103 and the target interface (i.e., the width of the low refractive index gap), the device can cut off the TE polarization mode. Therefore, the polarization controller 101 provided by the present invention has the advantages of nanoscale light field confinement capability and polarization selection effect, as well as high extinction ratio, low loss, small device size, etc.

[0043] It should be noted that the cross section of the nanowire 103 in the embodiment of the present invention is circular.

[0044] Specifically, after non-polarized light is incident from one end of the nanowire 103, the polarization controller 101 generates a new hybrid plasma TM mode. Its light energy is distributed in the oxide film 104 between the nanowire 103 and the metal substrate 102. When the thickness of the oxide film 104 is reduced to the nanoscale, the TM hybrid mode is strongly confined in the oxide film 104, showing a light field focusing capability that breaks the diffraction limit. When the diameter of the nanowire 103 is reduced, the TE mode in the nanowire 103 can be cut off, and the TE mode light energy quickly leaks out of the polarization controller 101, while the new TM hybrid plasma mode is not affected, and the light energy is still strongly confined in the oxide film, realizing a nano-focused TM polarized light field.

[0045] It should be noted that in the TM mode (Transverse Magnetic Mode), that is, the transverse magnetic mode, the magnetic field vector is completely perpendicular to the propagation direction of the electromagnetic wave, and the longitudinal magnetic field component is equal to zero. In the TE mode (Transverse Electric Mode), that is, the transverse electric mode, the electric field vector is completely perpendicular to the propagation direction of the electromagnetic wave, and the longitudinal electric field component is equal to zero.

[0046] As an optional embodiment, the material of the metal substrate is selected from one or more of gold, silver, aluminum, copper and indium.

[0047] It should be noted that when the diameter of the nanowire 103 and the distance between the nanowire 103 and the metal substrate layer 102 remain unchanged, the extinction ratio of the aluminum substrate is the highest, followed by the silver substrate and the copper substrate, and the lowest extinction ratio is the gold substrate and the indium substrate.

[0048] When the structural parameters of the metal substrate remain unchanged, the propagation loss of the gold substrate is the lowest, followed by the silver substrate and the aluminum substrate, and the highest propagation loss is the copper substrate and the indium substrate. Comparing the sub-wavelength binding strength, the aluminum substrate has the best effect, followed by the silver substrate and the copper substrate, and the gold substrate and the indium substrate have the worst effect.

[0049] In summary, the material of the metal substrate is preferably silver.

[0050] As an optional embodiment, the material of the oxide dielectric layer 104 is silicon dioxide.

[0051] It should be noted that, when the material of the oxide dielectric layer 104 is silicon dioxide, the refractive index of the oxide dielectric layer 104 is 1.444.

[0052] As an optional embodiment, the material of the nanowire 103 is silicon.

[0053] As an optional embodiment, the cross section of the nanowire 103 is circular, and the diameter of the nanowire 103 is 100 to 300 nanometers.

[0054] As an optional embodiment, the diameter of the nanowire 103 is 180 to 220 nanometers. It should be noted that, when the material of the nanowire 103 is silicon, the refractive index of the nanowire 103 is 3.476.

[0055] As an optional embodiment, the distance between the nanowire 103 and the target interface is no more than 25 nanometers, and the target interface is the interface between the metal substrate layer 102 and the oxide dielectric layer 104 .

[0056] As an optional embodiment, the distance between the nanowire 103 and the target interface is 2 to 5 nanometers.

[0057] As an optional embodiment, the polarization controller 101 operates in a transverse magnetic mode TM.

[0058] As an optional embodiment, the wavelength range of the unpolarized light is 800 to 1600 nanometers.

[0059] It should be noted that the wavelength range of the non-polarized light in the embodiment of the present invention can be determined based on the communication band 1550 nm. For example, the wavelength range of the non-polarized light can be 1500 to 1600 nm.

[0060] When the wavelength of the non-polarized light increases, the extinction ratio of the polarization controller 101 increases with the increase of the wavelength of the non-polarized light, the transmission loss of the polarization controller 101 increases with the increase of the wavelength of the non-polarized light, and the effective mode area of ​​the polarization controller 101 decreases first and then increases. Overall, the changes caused by the increasing wavelength of the non-polarized light are consistent with the changes in the diameter of the nanowire 103 while keeping the distance between the nanowire 103 and the target interface and the wavelength of the non-polarized light unchanged.

[0061] When the wavelength of the incident non-polarized light is 1550 nm, the polarization extinction ratio of the polarization controller 101 is greater than 7.6675 dB / μm, the transmission loss is less than 1.2553 dB / μm, and the mode field area is 0.0682393 μm 2 (≈ ), which is less than the free space diffraction limit .

[0062] The polarization controller 101 provided by the present invention has a specific nanowire 103 diameter, a specific low refractive index gap width, and a specific working mode. It exhibits nanoscale light confinement capability, low loss, and high extinction ratio performance at a wavelength of 1550nm, and will play a role in coherent optical communications, fiber optic gyroscopes, micro-nano optics, nonlinear optics, polarization imaging, and other fields.

[0063] The distance between the nanowire 103 and the target interface h When the diameter of the nanowire 103 is 2 nm and the diameter of the nanowire 103 is 200 nm, the mode field distribution of the polarization controller 101 provided by the present invention is calculated using the time-domain finite difference method. Figure 3 It is an electric field distribution diagram of the polarization controller 101 provided by the present invention in the TM mode. Figure 4 This is the electric field distribution diagram of the polarization controller 101 provided by the present invention in the TE mode.

[0064] Figure 3 and Figure 4 The circular white dotted line in the figure indicates the location of the nanowire 103. Figure 3 and Figure 4 The straight white dashed line in the figure represents the target interface.

[0065] like Figure 3 and Figure 4 As shown, when the wavelength of the incident non-polarized light is 1550nm, the TM electric field distribution diagram of the polarization controller 101 provided by the present invention shows that a strong electric field appears in the low refractive index gap of the polarization controller 101, while the TE mode field distribution diagram shows that there is almost no light in the low refractive index gap of the polarization controller 101.

[0066] To further analyze the light field characteristics of the pattern, calculate the current situation along x=0 and y= 0.1512μm (low refractive index gap) in both directions. In TM mode, the half-width along the x=0 direction is smaller than the width of the low refractive index gap. When the width of the low refractive index gap is 2nm, the half-width along the x=0 direction is less than 2nm, which is completely nanometer-level. The full width at half maximum in the 0.1512 μm direction is 6.48 nm.

[0067] It follows that, whether along x=0 or y= 0.1512μm, the light field of TM mode completely reaches the nanometer level, and the full width at half maximum in the x=0 direction is less than 2nm. In comparison, the electric field distribution at the low refractive index gap along the x=0 direction in the TE mode is almost non-existent in the entire electric field distribution, and along the y= The electric field at 0.1512μm has no photoelectric reaction with the metal. The larger the width of the low-refractive index gap, the smaller the electric field strength, and it is almost 0 at x=0.

[0068] Furthermore, the diameter of the nanowire 103 in the polarization controller 101 is d and the distance between the nanowire 103 and the target interface h While maintaining the diameter of the nanowire 103 d When the distance between the nanowire 103 and the target interface is constant at 200 nm, h As the wavelength decreases from 25nm to 2nm, the transmission loss of the polarization controller 101 increases from 1.2553dB / μm to 2.0781dB / μm, the extinction ratio of the polarization controller 101 increases from 4.4951dB / μm to 7.6675dB / μm, and the mode field area of ​​the polarization controller 101 decreases from 0.11829μm. 2 (≈ ) is reduced to 0.0682393μm 2 (≈ ).

[0069] While maintaining the distance between the nanowire 103 and the target interface h When the diameter of the nanowire 103 is 2 nm, d As the wavelength increases from 100 nm to 300 nm, the transmission loss of the polarization controller 101 increases continuously, from 0.55715 dB / μm to 4.445 dB / μm, the extinction ratio of the polarization controller 101 increases continuously, from 1.19235 dB / μm to 11.117 dB / μm, and the mode field area of ​​the polarization controller 101 decreases first and then increases, from 0.273007 μm 2 (≈ ) is reduced to 0.0682393μm 2 (≈ ), and then increased to 0.087898μm 2 (≈ ).

[0070] In summary, the diameter of the nanowire 103 d Preferably, the distance between the nanowire 103 and the target interface is 200 nm. h Preferably it is 2-5 nm.

[0071] Figure 5 It is a correlation diagram between metal substrates of different materials and extinction ratio and transmission loss of the polarization controller 101 provided by the present invention. Figure 6 It is a correlation diagram between the diameter of the nanowire 103 and the effective mode field area in the polarization controller 101 provided by the present invention.

[0072] like Figure 5 As shown, while maintaining the diameter of the nanowire 103 d and the distance between the nanowire 103 and the target interface h Under the same conditions, the extinction ratio of the aluminum substrate and the silver substrate is higher than that of the metal substrate layer 102 made of other materials, and the transmission loss is also relatively low.

[0073] like Figure 6 As shown, as the diameter of the nanowire 103 d increases, the effective mode field area of ​​the polarization controller 101 decreases first and then increases. d The binding strength is highest when the diameter is 200 nm.

[0074] When the material of the metal substrate layer 102 of the polarization controller 101 is a precious metal nanomaterial such as gold, silver, aluminum, copper and indium, the light binding intensity can break through the diffraction limit and achieve nanoscale light confinement. The fluctuation range of the mode area is within to , which is less than the diffraction limit in vacuum .

[0075] The polarization controller in the embodiment of the present invention includes a metal substrate layer, a nanowire and an oxide medium layer, wherein the oxide medium layer is arranged above the metal substrate layer, the nanowire extends in a straight line, the nanowire is arranged inside the oxide medium layer, the nanowire is parallel to the metal substrate layer, one end of the nanowire is the incident end of the non-polarized light, and the gap between the other end of the nanowire and the metal substrate layer is the exit end of the polarized light. The polarization controller has a simple structure and is easy to manufacture. By adjusting the diameter of the nanowire, the TE mode in the nanowire can be cut off to realize the TM polarized light field. By forming a low refractive index gap between the nanowire and the metal layer, the focusing and polarization functions can be realized at the nanoscale. Due to the discontinuity of the electric field at the interface between the low-emissivity gap and the high-refractive-index nanowire, the light field in the low-emissivity gap between the nanowire and the metal substrate layer is enhanced and coupled with the plasma wave on the surface of the metal substrate layer, thereby achieving precise confinement of the light field at the nanoscale, breaking through the diffraction-limited light field limitation, and realizing the regulation of the polarization state of light waves at the nanoscale. At the same time, due to the requirements of the plasmons of the metal substrate layer on the polarization mode, nano-focused TM polarized light field can be achieved. This device has broad application prospects.

[0076] The polarization controller provided by the present invention not only has the advantages of nanoscale light confinement capability, low-loss propagation, high extinction ratio and small device size, but also has a wide wavelength application range, which can meet the specific requirements of different application fields for the polarization state of light, thereby promoting the miniaturization of photonic devices and promoting the development of high-density photonic integration technology.

[0077] Based on the contents of the above embodiments, an optical device includes: a polarization controller 101 as described in any one of the above embodiments.

[0078] The optical device in the embodiment of the present invention includes a polarization controller 101 as described above, which can be better integrated with nanoscale electronic devices, can realize high-performance, compact optoelectronic integrated systems, provide innovative solutions for the next generation of optoelectronic integrated systems, can realize the deep integration of nanophotonics and electronics, and can better promote the development of high-performance, miniaturized optoelectronic devices.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A polarization controller, characterized in that: include: Metal substrate layer, nanowires and oxide dielectric layer; The oxide dielectric layer is disposed above the metal substrate layer; The nanowire extends in a straight line, the nanowire is arranged inside the oxide dielectric layer, and the nanowire is parallel to the metal substrate layer; One end of the nanowire is the incident end of non-polarized light, and the gap between the other end of the nanowire and the metal substrate layer is the emitting end of polarized light.

2. The polarization controller according to claim 1, characterized in that: The material of the metal substrate is selected from one or more of gold, silver, aluminum, copper and indium.

3. The polarization controller according to claim 1, characterized in that: The material of the oxide dielectric layer is silicon dioxide.

4. The polarization controller according to claim 1, characterized in that: The material of the nanowire is silicon.

5. The polarization controller according to claim 1, characterized in that: The distance between the nanowire and the target interface is no more than 25 nanometers, and the target interface is the interface between the metal substrate layer and the oxide dielectric layer.

6. The polarization controller according to claim 1, characterized in that: The cross section of the nanowire is circular, and the diameter of the nanowire is 100 to 300 nanometers.

7. The polarization controller according to claim 5, characterized in that: The distance between the nanowire and the target interface is 2 to 5 nanometers.

8. The polarization controller according to claim 1, characterized in that: The polarization controller operates in a transverse magnetic mode (TM).

9. The polarization controller according to any one of claims 1 to 8, characterized in that: The wavelength of the unpolarized light is in the range of 800 to 1600 nanometers.

10. An optical device, characterized in that: include: A polarization controller as claimed in any one of claims 1 to 9.

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