Optical fiber interference structure, method for manufacturing the same, optical fiber modulator, and optical modulation device

Abstract

Optical fiber interference structure, preparation method thereof, optical fiber modulator and optical modulation device. The optical fiber interference structure comprises: a first optical fiber segment comprising a first cross section and a second cross section located on both sides of the axial direction, and a first axial surface connecting the first cross section and the second cross section; a second optical fiber segment comprising a third cross section and a fourth cross section located on both sides of the axial direction, and a second axial surface connecting the third cross section and the fourth cross section; a connecting optical fiber segment, one end of the connecting optical fiber segment is connected with the first cross section in a radial direction, and the core of the first optical fiber segment is exposed; the other end of the connecting optical fiber segment is connected with the third cross section; a transparent conductive layer, which is coated on the outside of the connecting optical fiber segment, the first cross section, the third cross section, the second axial surface and at least part of the first axial surface; wherein the first cross section and the third cross section are parallel to each other, and the orthogonal projection of the core of the first optical fiber segment on the plane where the third cross section is located is located within the range of the third cross section.

Description

Technical Field

[0001] This article relates to but is not limited to optical modulator technology, in particular to an optical fiber interference structure and its preparation method, an optical fiber modulator and an optical modulation device. Background Art

[0002] Optical modulators transfer modulated signals to carrier lightwaves, causing the carrier lightwave's parameters to change in response to the modulated signal. This results in regular variations in the output optical signal's phase, frequency, and intensity. These modulators are widely used in long-distance, high-speed optical communication systems. They play a crucial role in optical information processing systems, optical interconnects, and optical communication networks.

[0003] With the development and popularization of optical fiber networks, optical fiber modulators have been widely used. However, the cost of optical fiber modulators is relatively high. Summary of the Invention

[0004] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0005] In a first aspect, an embodiment of the present application provides an optical fiber interference structure, comprising: a first optical fiber segment, comprising a first section and a second section located on both sides of the axial direction, and a first axial plane connecting the first section and the second section; a second optical fiber segment, comprising a third section and a fourth section located on both sides of the axial direction, and a second axial plane connecting the third section and the fourth section; a connecting optical fiber segment, one end of the connecting optical fiber segment is radially offset and connected to the first section, exposing the core of the first optical fiber segment; the other end of the connecting optical fiber segment is connected to the third section; a transparent conductive layer is coated on the outside of the connecting optical fiber segment, the first section, the third section, the second axial plane, and at least part of the first axial plane; wherein the first section and the third section are parallel to each other, and the orthographic projection of the core of the first optical fiber segment on the plane where the third section is located is within the range of the third section.

[0006] In an exemplary embodiment, a first angle is formed between the fourth section and the third section, so that light from the first optical fiber segment is not reflected back to the first optical fiber segment after being irradiated by the fourth section.

[0007] In an exemplary embodiment, the first optical fiber segment includes at least one fiber core.

[0008] In an exemplary embodiment, the first optical fiber segment is a single-mode optical fiber.

[0009] In an exemplary embodiment, in the axial direction of the first optical fiber segment, a distance between the first cross section and the third cross section is greater than or equal to 100 μm and less than or equal to 200 μm.

[0010] In an example embodiment, the material of the transparent conductive layer comprises indium tin oxide.

[0011] In an example embodiment, the thickness of the transparent conductive layer is greater than or equal to 30 nm and less than or equal to 100 nm in the radial direction of the first fiber segment.

[0012] In a second aspect, an embodiment of the present application provides a preparation method of a fiber interference structure, comprising: misaligning and fusing a first cross section of a first fiber segment and one end of a connecting fiber segment, and exposing a fiber core of the first fiber segment; misaligning and fusing the other end of the connecting fiber segment and a third cross section of a second fiber segment, so that the first cross section and the third cross section are parallel to each other, and the normal projection of the fiber core of the first fiber segment on the plane where the third cross section is located is located within the range of the third cross section; wherein the first fiber segment comprises the first cross section, a second cross section located on the two sides of the axial direction, and a first axial surface connecting the first cross section and the second cross section; the second fiber segment comprises the third cross section, a fourth cross section located on the two sides of the axial direction, and a second axial surface connecting the third cross section and the fourth cross section; forming a transparent conductive layer, the transparent conductive layer is wrapped outside the connecting fiber segment, the first cross section, the third cross section, the second axial surface, and at least part of the first axial surface.

[0013] In a third aspect, an embodiment of the present application provides a fiber modulator, comprising: a solution box, a direct current power supply, and a fiber interference structure as described above; wherein the solution box is provided with a liquid medium, the liquid medium is in contact with the transparent conductive layer of the fiber interference structure, at least part of the liquid medium is located on the optical path between the first cross section and the third cross section of the fiber interference structure, the second cross section of the fiber interference structure and at least part of the transparent conductive layer are exposed outside the liquid medium; one electrode of the direct current power supply is connected with the liquid medium, the other electrode of the direct current power supply is connected with the transparent conductive layer exposed outside the liquid medium; the direct current power supply is arranged to excite the Pockels effect of the liquid medium, so that the refractive index of the liquid medium changes; the second cross section of the fiber interference structure is arranged to receive an optical signal, and the optical signal is modulated after passing through the fiber interference structure.

[0014] In an example embodiment, the liquid medium in the solution box is a polar liquid or solution.

[0015] In an example embodiment, the solution box is located between the first cross section and the third cross section of the fiber interference structure and surrounds the outside of the fiber interference structure; or, the solution box surrounds the outside of the first cross section, the third cross section and at least part of the connecting fiber segment along the radial direction of the first fiber segment of the fiber interference structure; or, the solution box surrounds the outside of the second fiber segment, the connecting fiber segment and part of the first fiber segment of the fiber interference structure.

[0016] In an example embodiment, a housing is further included, which surrounds the outside of the solution box and the fiber interference structure.

[0017] In an example embodiment, the housing includes a connecting port, through which the second cross section of the fiber interference structure receives the optical signal.

[0018] In a fourth aspect, an embodiment of the present application provides an optical modulation device, which includes the fiber modulator as described above.

[0019] In an example embodiment, a light source and a spectrometer are further included, which are respectively connected with the second cross section of the fiber interference structure in the fiber modulator.

[0020] The fiber interference structure provided by the embodiment of the present application sequentially connects the first fiber segment, the connecting fiber segment and the second fiber segment along the axial direction, exposes the fiber core of the first fiber segment by setting the connecting fiber segment to be radially misaligned with the first fiber segment, and makes the opposite side surfaces of the first fiber segment and the second fiber segment parallel to each other, so that a Fabry-Perot interference cavity is formed on the opposite side surfaces of the first fiber segment and the second fiber segment. The fiber interference structure provided by the embodiment of the present application is simple, easy to manufacture and low in cost.

[0021] Other aspects can become apparent from the following detailed description, taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0022] The accompanying drawings are included to provide a further understanding of the present application, and constitute a part of the specification, illustrate the present application, and are used to explain the technical solutions of the present application, but do not limit the present application.

[0023] Figure 1 The schematic diagram of the fiber interference structure provided by the embodiment of the present application is shown in FIG. 1;

[0024] Figure 2 The schematic diagram of the fiber interference structure provided by the embodiment of the present application is shown in FIG. 1; Figure 1 The sectional view along the AA direction in FIG. 1;

[0025] Figure 3 The schematic diagram of the fiber interference structure provided by the embodiment of the present application is shown in FIG. 1;

[0026] Figure 4 Structure diagram of an optical fiber modulator in an exemplary embodiment;

[0027] Figure 5 Structure diagram of an optical fiber modulator in another exemplary embodiment;

[0028] Figure 6 Structure diagram of an optical fiber modulator in yet another exemplary embodiment;

[0029] Figure 7 Structure diagram of an optical fiber modulator in yet another exemplary embodiment;

[0030] Figure 8 Structure diagram of an optical modulating device in an exemplary embodiment;

[0031] Figure 9 Figure 8 Interference spectrum of the optical modulating device shown under different modulation voltages;

[0032] Figure 10 Figure 9 Intensity modulation fitting curve diagram of the spectral curve in

[0033] Figure 11 Phase modulation fitting curve diagram of the spectral curve in Figure 9 DETAILED DESCRIPTION

[0034] The present application describes a number of embodiments, but the description is exemplary rather than limiting, and it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible within the scope of the embodiments described in the present application. Although a number of possible combinations of features have been set forth herein, and discussed in the specific implementation, many other combinations of the disclosed features are possible. Unless specifically intended otherwise, any feature or element of any embodiment can be used in combination with any other feature or element of any other embodiment, or in replacement of any other feature or element in any other embodiment.

[0035] ​​​The present application includes and contemplates combinations of features and elements known to those of ordinary skill in the art. The presently disclosed embodiments, features and elements can also be combined with any conventional feature or element to form a unique invention. Any feature or element of any embodiment can also be combined with features or elements from other invention to form another unique invention. Therefore, it is to be understood that any feature shown and / or discussed in the present application can be realized alone or in any appropriate combination. Thus, the embodiments are not to be limited by any of the foregoing, except in accordance with the following claims and their equivalents.

[0036] Furthermore, in describing representative embodiments, the specification can have presented the method and / or process as a particular sequence of steps. However, to the extent that the method or process depends on more than one step, the method or process should not be limited to the particular sequence of steps described. Other sequences of steps can also be possible. The particular sequence of steps described should not be construed as being limiting of the claims. The claims should not be limited to the performance of their steps in the order written, and one skilled in the art can readily adapt the methods and / or processes to provide functions differing from those that can be described or claimed.

[0037] The main work of the fiber modulator is to realize the conversion of optical signals, and generally requires the device to have a large bandwidth, good stability, low loss and high modulation efficiency, etc. After the optical signal transmitted in the optical fiber passes through the modulation medium, the output amplitude, wavelength, frequency, intensity, phase, polarization state, etc. change, become modulated optical signals, and then pass through the optical fiber to the photoelectric device, demodulator, etc. After the device, the modulation signal parameters are obtained. In the whole process, the optical fiber acts as a medium to transmit and modulate light. The integrated fiber modulator has the advantages of simple light intensity control, low insertion loss, low transmission loss, wide frequency band, good stability, etc. and is applied in many fields, such as electro-optic modulation system, interference system, wavelength division multiplexing system, etc.

[0038] The core components of the fiber modulator are interferometer, tapered optical fiber and other structures, and need to be doped with metal ions or modified with expensive two-dimensional materials, and the preparation process is complex and the cost is high.

[0039] The embodiment of the present application provides a fiber interference structure, which comprises:

[0040] The first fiber section comprises a first cross section and a second cross section located on both sides of the axial direction, and a first axial surface connecting the first cross section and the second cross section.

[0041] The second optical fiber segment includes a third section and a fourth section located on both sides of the axial direction, and a second axial surface connecting the third section and the fourth section;

[0042] a connecting optical fiber segment, wherein one end of the connecting optical fiber segment is connected to the first cross section in a radially dislocated manner to expose the core of the first optical fiber segment; and the other end of the connecting optical fiber segment is connected to the third cross section;

[0043] a transparent conductive layer covering the outer side of the connecting optical fiber segment, the first cross section, the third cross section, the second axial surface, and at least a portion of the first axial surface;

[0044] The first section and the third section are parallel to each other, and the orthographic projection of the core of the first optical fiber segment on the plane where the third section is located is located within the range of the third section.

[0045] The optical fiber interference structure provided in the embodiments of the present application sequentially connects a first optical fiber segment, a connecting optical fiber segment, and a second optical fiber segment along the axial direction. By arranging the connecting optical fiber segment and the first optical fiber segment to be radially offset, the core of the first optical fiber segment is exposed, and the opposing side surfaces of the first and second optical fiber segments are parallel to each other, thereby forming a Fabry-Perot (FP) interference cavity on the opposing side surfaces of the first and second optical fiber segments. The optical fiber interference structure provided in the embodiments of the present application is simple, easy to manufacture, and low-cost.

[0046] Figure 1 Schematic diagram of the optical fiber interference structure provided in the embodiment of the present application. Figure 1 As shown, the optical fiber interference structure 100 provided in an embodiment of the present application includes a first optical fiber segment 11, a connecting optical fiber segment 12, and a second optical fiber segment 13, which are sequentially connected along the axial direction, and a transparent conductive layer 14. The first optical fiber segment 11 includes a first cross-section C1 and a second cross-section C2 located on either side of the first optical fiber segment 11, as well as a first axial plane E1 connecting the first and second cross-sections C1 and C2. The second optical fiber segment 13 includes a third cross-section C3 and a fourth cross-section C4 located on either side of the second optical fiber segment 13, as well as a second axial plane E2 connecting the third and fourth cross-sections C3 and C4. One end of the connecting optical fiber segment 12 is radially offset from the first cross-section C1, exposing the core of the first optical fiber segment 11; the other end of the connecting optical fiber segment 13 is connected to the third cross-section C3. The first and third cross-sections C1 and C3 are parallel to each other, and the orthographic projection of the core of the first optical fiber segment 11 onto the plane of the third cross-section C3 lies within the range of the third cross-section C3. The transparent conductive layer 14 covers the connecting optical fiber segment 12, the first cross-section C1, the third cross-section C3, the second axial plane E2, and at least a portion of the first axial plane E1. Figure 1The arrows in the figure illustrate the transmission of the light Lt in the FP interferometer cavity of the first optical fiber segment 11 and the second optical fiber segment 13. The first optical fiber segment 11 can be an input optical fiber, and the second optical fiber segment 13 can be a reflection optical fiber. The light Lt is emitted from the core of the first optical fiber segment 11, irradiates the third section C3 of the second optical fiber segment 13, and then reflects back.

[0047] The fiber-optic interferometer structure provided in the embodiments of the present application is a fiber-optic FP interferometer structure. This structure requires no external optical components and features a simple structure, smaller size, higher integration, and low cost. It can be easily integrated with other fiber-optic systems and can be flexibly applied in various scenarios. Furthermore, the optical path of the fiber-optic FP interferometer structure is not a free-space optical path, resulting in more robust optical path alignment and less sensitivity to environmental factors such as temperature, humidity, vibration, air flow, and dust. Consequently, it requires less maintenance over extended periods of use.

[0048] In an exemplary embodiment, the first optical fiber segment 11 may include a single core. In other embodiments, the first optical fiber segment 11 may include two or more cores. Compared to a single core configuration, using a first optical fiber segment 11 with two or more cores requires higher precision in terms of component size, angles, and process. Otherwise, light interference in the FP interferometer cavity is likely to occur, affecting the light modulation effect.

[0049] In an exemplary embodiment, the first optical fiber segment 11 may be a single-mode optical fiber. Because single-mode optical fibers are widely applicable and inexpensive, they help reduce the cost of the optical fiber interference structure provided in the embodiments of the present application and facilitate the adaptation of the optical fiber interference structure to other devices, particularly those in the communications field.

[0050] Figure 2 for Figure 1 The cross-sectional view along the AA direction. Figure 1 and Figure 2 As shown, when the first optical fiber segment 11 adopts a single-mode optical fiber, the outer diameter D1 of the first optical fiber segment 11 is about 125 microns (μm), and the core diameter D2 of the optical fiber core of the first optical fiber segment 11 is about 8 μm.

[0051] In an exemplary embodiment, Figure 1 As shown, the fourth section C4 of the second optical fiber segment 13 may have a first angle a1 with the plane where the third section C3 is located, so that the light from the first optical fiber segment 11 will not be reflected back to the first optical fiber segment 11 after being irradiated by the fourth section C4.

[0052] In an exemplary embodiment, the first angle a1 may be approximately 8 degrees. The size of the first angle a1 may be set as needed, and the present application does not limit this.

[0053] In an exemplary embodiment, the second optical fiber segment 13 may be a single-mode optical fiber or other types of optical fibers, which is not limited in the present application.

[0054] In an exemplary embodiment, Figure 1 As shown, the connecting optical fiber segment 12 can include two cross-sections located on both sides of its own axial direction, and an axial surface connecting the two cross-sections. The first cross-section C1 can be connected to one cross-section of the connecting optical fiber segment 12, and the third cross-section C3 can be connected to the other cross-section of the connecting optical fiber segment 12. With this arrangement, the connecting surface between the connecting optical fiber segment 12 and the first optical fiber segment 11 and the second optical fiber segment 13 is a flat surface, making the connection easier.

[0055] In an exemplary embodiment, the connecting optical fiber segment 12 can be a single-mode optical fiber or other types of optical fibers. The connecting optical fiber segment 12 can be connected to the first optical fiber segment 11 and the second optical fiber segment 13 by fusion splicing, which can be prepared using only a fusion splicer, which is simple and convenient.

[0056] In an exemplary embodiment, the length of the interference arm of the optical fiber interference structure 100 is the distance between the first section C1 and the third section C2 along the axial direction of the first optical fiber segment 11 , that is, the length of the connecting optical fiber segment 12 along the axial direction of the first optical fiber segment 11 .

[0057] For the optical fiber interference structure 100 provided in the embodiment of the present application, the refractive index sensitivity in the FP interference cavity can be calculated using formula (1).

[0058] △λ ν / △n=λ ν / n gas ; (1)

[0059] Among them, △λ ν represents the change in wavelength of light after passing through the FP interferometer cavity, △n represents the change in refractive index of light after passing through the FP interferometer cavity, △λ ν / △n represents the refractive index sensitivity, λ ν represents the central wavelength of the reflection interference valley, n gas It represents the refractive index of the medium in the FP interferometer cavity when the light transmission medium in the FP interferometer cavity is gas. The value of the medium refractive index is related to the light transmission medium used in the FP interferometer cavity.

[0060] According to formula (1), the refractive index sensitivity within the FP interferometer cavity is independent of the length of the interferometer arm. However, the length of the interferometer arm affects the free spectral range (FSR) of the light, and the length of the interferometer arm also affects the intensity of the light interference spectrum. Therefore, the length of the interferometer arm can be set according to actual needs, for example, the length of the interferometer arm can be set according to the desired free spectral range.

[0061] In an exemplary embodiment, the free spectral range of the FP interferometer can be calculated using the following formula (2):

[0062] △λ f =λ 2 / 2nL; (2)

[0063] Where λ is the wavelength of the incident light, n is the refractive index of the medium in the FP interferometer cavity, L is the length of the interferometer arm, △λ f is the free spectral range of the FP interferometer.

[0064] From formula (2), it can be seen that the longer the length L of the interference arm is, the smaller the free spectral range of the FP interferometer is; the larger the refractive index n of the medium in the FP interferometer cavity is, the smaller the free spectral range of the FP interferometer is; the longer the wavelength λ of the incident light is, the smaller the free spectral range of the FP interferometer is. f When the refractive index n of the medium in the FP interferometer cavity and the wavelength λ of the incident light are determined, the required length L of the interferometer arm can be calculated according to the above formula (2), and the structural parameters of the fiber optic interferometer structure 100 can be designed accordingly.

[0065] In an exemplary embodiment, Figure 1 As shown, the axial length of the connecting optical fiber segment 12 along the first optical fiber segment 11 is a first length S1 . The first length S1 may be greater than or equal to 100 μm and less than or equal to 200 μm. For example, the first length S1 may be approximately 150 μm.

[0066] In an exemplary embodiment, Figure 1 As shown, in the radial direction of the first optical fiber segment 11, there is a first offset distance H1 between the connecting optical fiber segment 12 and the first optical fiber segment 11, and a second offset distance H2 between the connecting optical fiber segment 12 and the second optical fiber segment 13. When the first optical fiber segment 11 and the second optical fiber segment 13 use optical fibers of the same specifications, the first offset distance H1 is equal to the second offset distance H2. Figure 1In the figure, the first misalignment distance H1 is indicated by the distance between the lower surface of the connecting optical fiber segment 12 and the lower surface of the first optical fiber segment 11. The first misalignment distance H1 may also be the distance between the axial centerline of the connecting optical fiber segment 12 and the axial centerline of the first optical fiber segment 11 along the radial direction of the first optical fiber segment 11. The second misalignment distance H2 is indicated in the same manner as the first misalignment distance H1.

[0067] In an exemplary embodiment, H1>1 / 2D1+1 / 2D2. This arrangement ensures that the first optical fiber segment 11 is fully exposed. When this condition is met, the larger the connection area between the connecting optical fiber segment 12 and the first optical fiber segment 11, the more stable the connection between the two. For example, when both the first optical fiber segment 11 and the connecting optical fiber segment 12 are single-mode optical fibers, the first offset distance H1 can be approximately 68 μm.

[0068] In an exemplary embodiment, Figure 1 As shown, the transparent conductive layer 14 can be coated on the outside of the exposed surface of the optical fiber interference structure 100 except for the second cross section C2. In the radial direction along the first optical fiber segment 11, the thickness D3 of the transparent conductive layer 14 can be greater than or equal to 30 nanometers (nm) and less than or equal to 100 nm. The thickness D3 of the transparent conductive layer 14 can be set according to actual needs and actual process conditions. With the advancement of processes and technologies, the thickness D3 of the transparent conductive layer 14 can be set to be smaller or larger, and this application does not impose any restrictions on this.

[0069] In an exemplary embodiment, in the axial direction along the first optical fiber segment 11, the length of the transparent conductive layer 14 is a second length S2, and the second length S2 can be greater than or equal to 1.8 centimeters (cm) and less than or equal to 2.2 cm. For example, the second length S2 can be approximately 2 cm, which is not limited in this application.

[0070] In an exemplary embodiment, the transparent conductive layer 14 may be made of indium tin oxide (ITO). The inventors of this application have discovered that using ITO to form the transparent conductive layer 14 maximizes light transmission. However, when using materials such as gold (Au) or silver (Ag) to form the transparent conductive layer 14, even if the thickness of the transparent conductive layer 14 is thinner, the optical fiber interferometer structure 100 may not achieve the desired spectral effect. Furthermore, ITO, as the modulation electrode of the optical fiber interferometer structure, is easy to manufacture and integrate with other optical fiber systems.

[0071] In an exemplary embodiment, the transparent conductive layer 14 may be a continuous coating to facilitate subsequent connection with other structures such as a DC power supply.

[0072] The inventors have found that, when the first fiber segment 11 is a single-mode fiber, the transparent conductive layer 14 is ITO, the thickness of the transparent conductive layer 14 is about 100 nm, and the second length S2 is about 2 cm, the light modulation simulation result of the fiber interference structure is best when the first length S1 is 150 μm.

[0073] Figure 3 A schematic diagram of a fiber interference structure according to another example embodiment. Figure 3 Compared with Figure 1 , the difference is that the transparent conductive layer 14 has a different coverage range, and the rest can refer to the description of the fiber interference structure of Figure 1 , which will not be repeated here.

[0074] As shown in Figure 3 , the transparent conductive layer 14 can expose the fourth cross section C4, and the transparent conductive layer 14 can expose the part of the first axial surface E1 on the side of the first fiber segment 11 away from the second fiber segment 13. Figure 3 In the structure shown in , the transparent conductive layer 14 has a smaller coverage range, which can save materials and facilitate subsequent further packaging and adaptation of the fiber interference structure.

[0075] In the example embodiment, the connecting fiber segment 12, the first fiber segment 11, and the second fiber segment 13 can be formed of the same specification fiber.

[0076] The application also provides a method for manufacturing a fiber interference structure, including: misaligning and fusing a first cross section of a first fiber segment with one end of a connecting fiber segment, and exposing a fiber core of the first fiber segment; misaligning and fusing the other end of the connecting fiber segment with a third cross section of a second fiber segment, so that the first cross section and the third cross section are parallel to each other, and the normal projection of the fiber core of the first fiber segment on the plane where the third cross section is located is within the range of the third cross section; wherein the first fiber segment includes the first cross section, a second cross section on the axial side, and a first axial surface connecting the first cross section and the second cross section; the second fiber segment includes the third cross section, a fourth cross section on the axial side, and a second axial surface connecting the third cross section and the fourth cross section; forming a transparent conductive layer, which covers the outside of the connecting fiber segment, the first cross section, the third cross section, the second axial surface, and at least part of the first axial surface.

[0077] The preparation method of the optical fiber interference structure provided in the embodiment of the present application adopts a large bias offset welding method to build an optical fiber FP interference structure. The connection between optical fiber segments can be achieved only by a welding machine. The method is simple and convenient. In the process of bias welding of the optical fiber, the type and size of the optical fiber can be selected as needed, which is convenient for adjusting the optical fiber FP interference structure. Large-scale industrial production can be achieved by standardizing the preparation parameters, which is convenient for promotion and application.

[0078] In an exemplary embodiment, forming the transparent conductive layer includes forming the transparent conductive layer using a magnetron sputtering method. For example, indium tin oxide may be deposited on the surfaces of the first optical fiber segment, the connecting optical fiber segment, and the second optical fiber segment after the offset fusion process to form the transparent conductive layer.

[0079] In this embodiment, the transparent conductive layer is formed by a magnetron sputtering method, and the preparation can be completed by using a magnetron sputtering device, which has a short production cycle and low cost. The thickness of the transparent conductive layer can be adjusted as needed, which facilitates large-scale industrial production.

[0080] The following Figure 1 The preparation process of the optical fiber interference structure in the embodiment is described, and the preparation method of the optical fiber interference structure of the present application is explained. In this embodiment, the optical fiber used is an ordinary single-mode optical fiber purchased from Changfei Optical Fiber Co., Ltd., and its structural parameters are: outer diameter 125μm, core diameter 8μm. The fusion splicer used for fusion splicing optical fibers is a KJ-260B fusion splicer produced by Nanjing Jilong. The magnetron sputtering system is a JGP-450B magnetron sputtering deposition system produced by Shenyang Scientific Instrument Co., Ltd., Chinese Academy of Sciences. Commercial ITO target material (purity 99.99%) was purchased from Zhongnuo New Materials (Beijing) Technology Co., Ltd.

[0081] (1) The first optical fiber segment and the third optical fiber segment are staggered and fused.

[0082] The single-mode optical fiber prepared in advance is preprocessed to obtain a first optical fiber segment, a second optical fiber segment and a third optical fiber segment.

[0083] Turn on the fusion splicer, clamp the first and third fiber segments in the fiber clamps, and adjust the splicing parameters in manual mode. Maintain a radial offset of 68 μm between the first and third fiber segments. Push the fibers together so that the splice point is centered on the splicer's viewing screen. Stop pushing just as the first and third fiber segments touch, and perform the spark splicing.

[0084] After the offset fusion splicing is completed, the first optical fiber segment and the third optical fiber segment fused together are taken out from the fusion splicer.

[0085] (2) Cut the third optical fiber segment to obtain a connecting optical fiber segment.

[0086] The third fiber segment is cut by using a fiber cutter under a body microscope to obtain a connecting fiber segment, and the axial length of the connecting fiber segment is 150 μm, so that the length of the interference arm between the opposite side surfaces of the first fiber segment and the second fiber segment is 150 μm.

[0087] After the cutting is completed, the first fiber segment and the connecting fiber segment are taken out, and attention is paid to preventing the optical fiber from being broken during the taking-out process.

[0088] (3) The connecting fiber segment and the second fiber segment are misaligned and fused.

[0089] The fusion machine is started, the connecting fiber segment and the second fiber segment are clamped in the fiber clamps, the positions of the connecting fiber segment and the second fiber segment are manually adjusted to make the opposite side surfaces of the first fiber segment and the second fiber segment completely aligned, the fiber is pushed to make the position of the fiber fusion point in the center of the field of view of the observation screen of the fusion machine, and the pushing is stopped when the connecting fiber segment and the second fiber segment just contact, and discharge fusion is performed.

[0090] In the example embodiment, during the alignment of the opposite side surfaces of the first fiber segment and the second fiber segment, the end of the first fiber segment away from the connecting fiber segment can be connected with a light source and a fiber spectrometer, respectively, and the positions of the first fiber segment and the second fiber segment are fine-tuned according to the spectrum received by the fiber spectrometer, and the higher the contrast of the obtained interference spectrum is, the higher the alignment degree of the opposite side surfaces of the first fiber segment and the second fiber segment is.

[0091] (4) The excess length of the first fiber segment and the second fiber segment is cut to obtain an initial fiber interference structure.

[0092] The first fiber segment and the second fiber segment with a longer length can be misaligned and fused first, and after the misalignment and fusion are completed, the excess length is cut to obtain an initial fiber interference structure with a proper size.

[0093] (5) An indium tin oxide layer is formed on the surface of the initial fiber interference structure to form a fiber interference structure.

[0094] The initial fiber interference structure is placed in a vacuum chamber of a magnetron sputtering system, the angle between the initial fiber interference structure and the target material plane is adjusted, the connecting surface between the first fiber segment, the connecting fiber segment and the second fiber segment can also be sputtered to ITO film, so as to ensure the continuity of the ITO film in the whole interference arm area.

[0095] In the exemplary embodiment, in the sputtering thin film process, for the ITO target material, the vacuum ignition voltage can be 600 V, the continuous sputtering voltage can be 400 V, and the current can be 80 mA. By performing continuous sputtering at a relatively low voltage, melting of the target material can be prevented, and smooth film coating process can be ensured.

[0096] The embodiment of the present application also provides an optical fiber modulator, comprising: a solution box, a direct current power supply and an optical fiber interference structure as described above; wherein the solution box is provided with a liquid medium, the liquid medium is in contact with a transparent conductive layer of the optical fiber interference structure, at least part of the liquid medium is located on an optical path between a first cross section and a third cross section of the optical fiber interference structure, a second cross section of the optical fiber interference structure and at least part of the transparent conductive layer are exposed outside the liquid medium; one electrode of the direct current power supply is connected with the liquid medium, and the other electrode of the direct current power supply is connected with the transparent conductive layer exposed outside the liquid medium; the direct current power supply is configured to excite the Pockels effect of the liquid medium, so that the refractive index of the liquid medium changes; the second cross section of the optical fiber interference structure is configured to receive an optical signal, and the optical signal is modulated after passing through the optical fiber interference structure.

[0097] The optical fiber modulator provided by the embodiment of the present application is provided with a liquid medium on an optical path between a first cross section and a third cross section of an optical fiber interference structure, a voltage is applied between a transparent conductive layer of the optical fiber interference structure and the liquid medium by a direct current power supply, the Pockels effect of the liquid medium is utilized to change the refractive index of the liquid medium, and then an optical signal received by the second cross section is modulated. The optical fiber modulator provided by the embodiment of the present application has a lower requirement for environmental factors, and helps to realize long-time stable work. Moreover, the Pockels effect of the liquid medium is utilized to realize optical modulation, the optical modulation process is more convenient, the modulation speed is more rapid, and the working efficiency of the optical modulator device is improved.

[0098] The optical fiber modulator provided by the embodiment of the present application can realize specific modulation of an optical signal and obtain a specific FSR spectrum by adjusting the structural parameters of the optical fiber interference structure, such as the length of the interference arm. The structure of the optical fiber interference structure can be designed according to actual needs, which is not limited in the present application. Through the research of the present inventor, there is no optical fiber interference structure 100 with the structure shown in the above embodiment, and there is no method of combining the optical fiber interference structure 100 with the Pockels effect to modulate an optical signal. The scheme of the present application provides a brand-new design idea of the optical fiber modulator.

[0099] In an exemplary embodiment, the positive electrode of the DC power supply is connected to the transparent conductive layer exposed outside the liquid medium, and the negative electrode of the DC power supply is connected to the liquid medium; or, the positive electrode of the DC power supply is connected to the liquid medium, and the negative electrode of the DC power supply is connected to the transparent conductive layer located outside the liquid medium.

[0100] Figure 4 FIG. 1 is a schematic diagram of the structure of an optical fiber modulator in an exemplary embodiment. Figure 4 As shown, the optical fiber modulator 300 includes a solution box 110, a DC power supply 160 and an optical fiber interference structure 100. The solution box 110 can be located between the first section C1 and the third section C3 of the optical fiber interference structure 100, and surround the outside of the connecting optical fiber segment 12. A liquid medium is provided in the solution box 110, and the liquid medium is in contact with the transparent conductive layer 14 on the outside of the connecting optical fiber segment 12. When the solution box 110 is located between the first section C1 and the third section C3, the solution box 110 can be made of a transparent material to avoid affecting the propagation of light. The positive pole of the DC power supply 160 can be connected to the transparent conductive layer 14 exposed outside the liquid medium, and the negative pole of the DC power supply 160 can be connected to the liquid medium. When powered on, the DC power supply 160 can excite the Pockels effect of the liquid medium. The second section C2 of the optical fiber interference structure 100 can be located outside the solution box 110 and is configured to receive external light signals. The first light signal from the second section C2 is emitted from the core of the first section C1, passes through the liquid medium in the solution box 110, and is reflected at the third section C3. The reflected light passes through the liquid medium in the solution box 110 again and enters the core of the first section C1. The first light signal is modulated into a second light signal, and the second light signal is emitted from the second section C2. Since the refractive index of the liquid medium changes under the Pockels effect, the first light signal from the outside world can be modulated into a second light signal. When the first light signal is continuously incident, the optical fiber modulator 300 can continuously output the second light signal to the outside world. When the structure of the optical fiber interference structure 100 is fixed, the modulation effect on the optical signal is basically fixed. Therefore, the specific structure of the optical fiber interference structure 100 can be designed in advance according to the required spectrum of the second light signal. Since the preparation of the optical fiber interference structure 100 is simple and the cost is low, the optical fiber modulator provided in the embodiment of the present application is also suitable for large-scale production and preparation, and is very easy to adapt to other structures of the optical modulation system.

[0101] In an exemplary embodiment, Figure 4As shown, the solution box 110 can be provided with a conductive column 111, one end of the conductive column 111 can extend into the liquid medium, and the other end of the conductive column 111 can be fixed to the inner side surface of the solution box 110 and contact a first electrode sheet (not shown) provided on the outer side surface of the solution box 110. One electrode of the direct current power supply 160 can be connected to the first electrode sheet to facilitate the provision of a voltage signal to the liquid medium. In an exemplary embodiment, the conductive column 111 and the first electrode sheet can be an integral structure.

[0102] In an exemplary embodiment, the solution box 110 and the optical fiber interference structure 100 are detachably connected, facilitating subsequent maintenance of the optical fiber modulator 300.

[0103] In an exemplary embodiment, the optical fiber modulator 300 can further include a second electrode sheet 112, which can be provided on the transparent conductive layer 14 exposed to the liquid medium, for example, can be located at any one of the first cylindrical surface E1, the second cylindrical surface E2, and the connecting optical fiber segment 12. Another electrode of the direct current power supply 160 can be connected to the transparent conductive layer 14 through the second electrode sheet 112.

[0104] In an exemplary embodiment, the direct current power supply 160 is a detachable structure, facilitating subsequent replacement.

[0105] In an exemplary embodiment, the liquid medium in the solution box 110 can be a liquid or solution capable of generating a Pockels effect under an energized state, for example, a polar liquid. In an exemplary embodiment, the liquid medium in the solution box 110 can be water, which is safe, non-toxic, stable, and easy to obtain, and helps to reduce the cost of the optical fiber modulator. In other embodiments, the liquid medium in the solution box 110 can be other inorganic or organic polar liquids, for example, pure hydrogen peroxide, hydrogen fluoride, hydrazine, thionyl chloride, phosphorus oxychloride, disulfide dichloride, sulfuryl chloride, arsenic trichloride, hydrogen chloride silicon, sulfuric acid, nitric acid, phosphoric acid, liquid ammonia, anhydrous perchloric acid, etc. A suitable liquid medium can be selected as needed, and the present application does not limit this.

[0106] Taking water as the liquid medium in the solution box 110 as an example, the transparent conductive layer 14 of the optical fiber modulator 300 as an electrode can participate in the Pockels effect of water. Since indium tin oxide is a transparent material, it will not affect the propagation of light in the F-P interference cavity. There is an electric double layer (EDL) between the transparent conductive layer 14 and the water. In the electric double layer, the electrical properties of the surface of the transparent conductive layer 14 can induce the orientation of oxygen atoms in water molecules, thereby causing the orientation order of water molecules. Under the action of an external electric field, the spatial distribution of water molecules in the electric double layer changes, causing a change in the effective refractive index (RI) of water near the transparent conductive layer 14.

[0107] In the example embodiment, as shown in Figure 4 The optical fiber modulator 300 can further include a housing 200, which can surround the solution box 110 and the optical fiber interference structure 100 outside, and can play a protective role to avoid damage to the optical fiber modulator 300 under external force during transportation or use. The DC power supply 160 can be arranged inside the housing 200, which has better protection effect. Alternatively, the housing 200 can be provided with a power supply accommodating space (not shown in the figure), and the DC power supply 160 can be installed in the power supply accommodating space. The DC power supply 160 can be connected to the first electrode sheet 111 and the second electrode sheet 112 in the power supply accommodating space. When the DC power supply 160 needs to be replaced later, the housing 200 does not need to be disassembled to complete the replacement, which is convenient for maintenance. A cover plate (not shown in the figure) can be arranged outside the power supply accommodating space to protect the DC power supply 160 in the power supply accommodating space.

[0108] In the example embodiment, as shown in Figure 4 The housing 200 further includes a connecting port 201, which is arranged outside the second cross section C2. The optical fiber and other structures outside can be connected to the core of the second cross section C2 through the connecting port 201, so as to provide the first optical signal to the optical fiber modulator 300. By arranging the connecting port 201, the optical fiber modulator 300 can be connected to the outside.

[0109] In the structure shown in Figure 4 The size of the solution box 110 is small, which helps to save costs and facilitate connection with the optical fiber interference structure 100.

[0110] Figure 5 For another example embodiment, a structure diagram of the optical fiber modulator is shown. Figure 5 The difference from Figure 4 is the shape of the solution box 110 and the shape of the housing 200. The remaining structures can refer to the description of the foregoing Figure 4 , which will not be described here.

[0111] As shown in Figure 5 The first cross section C1, the third cross section C3 and at least part of the connecting optical fiber segment 12 along the radial direction of the first optical fiber segment 11 are immersed in the liquid medium. The solution box 110 surrounds part of the surfaces of the first cylindrical surface E1 and the second cylindrical surface E2, wraps the F-P cavity between the first cross section C1 and the third cross section C3 in the liquid medium, and can expose the side of the connecting optical fiber segment 12 away from the first optical fiber segment 11 and the second optical fiber segment 13. In the case that the solution box 110 wraps the F-P cavity in the liquid medium, the solution box 110 can be made of light-proof material.

[0112] In an exemplary embodiment, as shown in Figure 5 The second cross section C2 of the fiber interference structure 100 can be exposed outside the shell 200, and the shell 200 is not provided with a connecting port, and the core of the second cross section C2 can be directly connected with a fiber or other structure outside.

[0113] In the structure shown in Figure 5 The solution box 110 surrounds the first cross section C1, the third cross section C3 of the fiber interference structure 100 and at least part of the connecting fiber segment 12 along the radial direction of the first fiber segment 11, and there is no surface of the solution box 110 between the first cross section C1 and the third cross section C3, so that the loss of light in the process of passing through the F-P interference cavity is smaller, which helps to improve the light modulation effect.

[0114] Figure 6 The structure of the fiber modulator in another exemplary embodiment is shown in the schematic view. Figure 6 The difference between Figure 5 is the shape of the solution box 110, and the rest of the structure can refer to the description of the foregoing Figure 5 , which will not be described here again.

[0115] As shown in Figure 6 The solution box 110 can be in the shape of "U", Figure 5 The first optical signal in Figure 6 The first optical signal needs to pass through a section of air path and the outer surface of the solution box 110 in the process of passing through the solution box 110. In the shell of the solution box 110, at least the shell near the optical path of the first optical signal is transparent material. The shape, size and coating of the solution box 110 can be set according to the distribution of the liquid medium and specific needs, and the present application does not limit this.

[0116] In the structure of Figure 6 The shape of the solution box 110 is more flexible, and the outer surface of the solution box 110 is designed in different shapes, which helps to adapt the shape of the solution box 110 and the fiber interference structure 100, and facilitates disassembly and assembly.

[0117] Figure 7 The structure of the fiber modulator in another exemplary embodiment is shown in the schematic view. As shown in Figure 7As shown, the solution box 110 can wrap outside the second fiber segment 13, the connecting fiber segment 12 and part of the first fiber segment 11. The transparent conductive layer 14 of the fiber interference structure 100 can be exposed at the fourth cross section C4 and part of the first axial surface E1 of the first fiber segment 11 away from the second fiber segment 13. One electrode of the direct current power supply 160 can directly extend into the liquid medium, and the other electrode of the direct current power supply 160 can be directly connected with the exposed transparent conductive layer 14. The transparent conductive layer 14 of the fiber interference structure 100 can be located inside the shell 200, and the second cross section C2 of the fiber interference structure 100 can be exposed outside the shell 200.

[0118] Figure 7 The remaining structures can refer to the foregoing descriptions of the fiber interference structure 100, which will not be repeated here. Figures 4 to 6

[0119] In the structure of the fiber interference structure 100, Figure 7 In the structure of the fiber interference structure 100, the solution box 110 has a large size, and the immersion range of the liquid medium is large, which is not only convenient for modulating light, but also helps to protect the fiber interference structure 100 and maintain the structural stability of the fiber modulator 300, and the size precision requirement of the solution box 110 is small.

[0120] In the example embodiment, Figures 4 to 7 The structures in the fiber interference structure 100 can be arbitrarily combined with each other, and the present application does not limit this.

[0121] The present application also provides a light modulation device, which comprises the fiber modulator as described above.

[0122] The light modulation device provided by the present application can be used as a sensing probe when applied to the field of fiber sensing, and can be used as a working electrode when applied to the field of electrochemistry. The light modulation device can also comprise an optical switch, and the fiber modulator can realize the function of the optical switch. The light modulation device can also be applied to scenes such as laser engineering and optical interference systems, and the present application does not limit this. In the example embodiment, the light modulation device comprises a light source, a spectrometer and the fiber modulator as described above, wherein the light source and the spectrometer are connected with the second cross section of the fiber modulator, respectively. The light modulation device provided by the present application has a simple structure, is easy to prepare, is safe and reliable, and is suitable for popularization and use.

[0123] Figure 8 FIG. 1 is a structural schematic diagram of a light modulation device in an example embodiment, which briefly shows a fiber modulator 300. As shown in FIG. 1, Figure 8 ​As shown, the optical modulation device includes a fiber modulator 300, a transmission fiber 120, a light source 130, a spectrometer 140, and a coupler 150. The second section C2 of the fiber modulator 300 is connected to the transmission fiber 120, and the transmission fiber 120 is connected to the light source 130 and the spectrometer 140 through the coupler 150.

[0124] In an exemplary embodiment, the light source 130 may be an amplified spontaneous emission (ASE) light source, the spectrometer 140 may be an optical spectrum analyzer (OSA), and the coupler 150 may be a 3 decibel (dB) fiber coupler.

[0125] The inventors of this application Figure 8 The optical modulation device shown was tested. During the test, a first optical signal from light source 130 traveled through transmission fiber 120 to fiber modulator 300. After modulation by fiber modulator 300, a second optical signal was generated, and the spectrum of the second optical signal was detected by spectrometer 140. The interference spectrum of the second optical signal was tested under different applied voltages. During the test, coupler 150 employed a wavelength division multiplexing coupler purchased from Changfei Optical Fiber Company; DC power supply 160 employed a regulated DC power supply purchased from Yangzhou Huatai Electronics Co., Ltd. as the phase-shift control power supply; and light source 130 employed an ASE light source purchased from Chengdu Liefeng Technology Co., Ltd. As the optical signal detector, spectrometer 140 employed a fiber spectrometer (Yokogawa AQ-6317B) purchased from the Guangzhao Technology R&D Center.

[0126] Figure 9 for Figure 8 Interference spectra of the light modulation device shown at different modulation voltages. Figure 9 The horizontal axis is wavelength (Wavelength), the unit is nanometer (nm), the vertical axis is intensity (Intensity), the unit is dB, Figure 9 The test voltages are 0 volts (V), 0.1V, 0.2V, 0.3V, 0.4V and 0.5V. Figure 9 As shown in Figure 2, under different test voltages, the shapes of the spectral curves are similar, the spectrum moves toward the direction of increasing wavelength, and the intensity gradually decreases. Figure 9 It can be seen that the optical modulation device has high modulation efficiency for optical signals and good modulation effect.

[0127] Figure 10 for Figure 9 Intensity modulation fitting curve of the spectral curve in . Figure 10 The horizontal axis is voltage, the unit is V, and the vertical axis is intensity, the unit is decibel milliwatt (dBm). Figure 10The discrete points in the figure represent the intensity corresponding to the test voltage value, with the y-coordinate as y and the x-coordinate as x. After intensity modulation fitting, y = -6.0327x - 61.5731 is obtained, and the fitting coefficient R 2 is 0.9971. It can be seen from Figure 10 that the fitting relationship presents a good linear range, which is helpful for calibration in actual application.

[0128] Figure 11 is Figure 9 the phase modulation fitting curve of the spectral curve in Figure 11 The x-coordinate in the figure is voltage, in V, and the y-coordinate is wavelength, in nm. Figure 11 The discrete points in the figure represent the wavelength corresponding to the test voltage value, with the y-coordinate as y and the x-coordinate as x. After intensity modulation fitting, y = 1.1789 + 1534.6909x is obtained, and the fitting coefficient R 2 is 0.9909. It can be seen from Figure 11 that the fitting relationship presents a good linear range, which is helpful for calibration in actual application.

[0129] It can be seen from Figures 9 to 11 that, compared with the light modulator device in the prior art, the light modulator device provided in the embodiment has a better spectral modulation effect.

[0130] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0131] In addition, the terms "first", "second", and the like are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second", and the like can explicitly or implicitly include at least one of the features.

[0132] In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, and the like, unless otherwise explicitly and specifically limited.

[0133] In the present application, unless specifically defined otherwise, the terms "mounting", "connected", "connection", "fixed", and the like should be construed broadly and do not necessarily imply that two or more elements are in any way connected to, or fixed to, or integrated with, each other. For people having ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0134] In the present application, unless specifically defined otherwise, the first feature is "on" or "under" the second feature can be that the first and second features are in direct contact, or the first feature and the second feature are in indirect contact through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0135] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the present application and the features of the different embodiments or examples without contradiction.

[0136] Although the embodiments of the present application have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. A fiber optic modulator, characterized in that: include: A solution box, a DC power supply and an optical fiber interference structure; wherein the optical fiber interference structure includes: The first optical fiber segment includes a first cross-section and a second cross-section located on both sides of the axis, and a first axial surface connecting the first cross-section and the second cross-section; The second optical fiber segment includes a third section and a fourth section located on both sides of the axial direction, and a second axial surface connecting the third section and the fourth section; a connecting optical fiber segment, wherein one end of the connecting optical fiber segment is connected to the first cross section in a radially dislocated manner to expose the core of the first optical fiber segment; and the other end of the connecting optical fiber segment is connected to the third cross section; a transparent conductive layer covering the outer side of the connecting optical fiber segment, the first cross section, the third cross section, the second axial surface, and at least a portion of the first axial surface; The first section and the third section are parallel to each other, and the orthographic projection of the core of the first optical fiber segment on the plane where the third section is located is located within the range of the third section; A liquid medium is provided in the solution box, and the liquid medium is in contact with the transparent conductive layer of the optical fiber interference structure. At least part of the liquid medium is located on the optical path between the first section and the third section of the optical fiber interference structure, and the second section of the optical fiber interference structure and at least part of the transparent conductive layer are exposed outside the liquid medium; one of the electrodes of the DC power supply is connected to the liquid medium, and the other electrode of the DC power supply is connected to the transparent conductive layer exposed outside the liquid medium; the DC power supply is configured to excite the Pockels effect of the liquid medium to change the refractive index of the liquid medium; the second section of the optical fiber interference structure is configured to receive an optical signal, and the optical signal is modulated after passing through the optical fiber interference structure.

2. The optical fiber modulator according to claim 1, wherein: There is a first angle between the fourth section and the third section, so that light from the first optical fiber segment will not be reflected back to the first optical fiber segment after being irradiated by the fourth section.

3. The optical fiber modulator according to claim 2, wherein: The first optical fiber segment includes at least one fiber core.

4. The optical fiber modulator according to claim 3, wherein: The first optical fiber segment is a single-mode optical fiber.

5. The optical fiber modulator according to claim 2, wherein: In the axial direction of the first optical fiber segment, a distance between the first cross section and the third cross section is greater than or equal to 100 μm and less than or equal to 200 μm.

6. The optical fiber modulator according to claim 2, wherein: The material of the transparent conductive layer includes indium tin oxide.

7. The optical fiber modulator according to claim 6, wherein: In a radial direction along the first optical fiber segment, a thickness of the transparent conductive layer is greater than or equal to 30 nm and less than or equal to 100 nm.

8. The optical fiber modulator according to any one of claims 1 to 7, characterized in that: The liquid medium in the solution box is a polar liquid.

9. The optical fiber modulator according to any one of claims 1 to 7, characterized in that: The solution box is located between the first section and the third section of the optical fiber interference structure and surrounds the outside of the optical fiber interference structure; or, the solution box surrounds the first section, the third section and the outside of at least part of the connected optical fiber segment along the radial direction of the first optical fiber segment of the optical fiber interference structure; or, the solution box surrounds the outside of the second optical fiber segment, the connected optical fiber segment and part of the first optical fiber segment of the optical fiber interference structure.

10. The optical fiber modulator according to any one of claims 1 to 7, characterized in that: The invention also includes a housing, which surrounds the solution box and the optical fiber interference structure.

11. The optical fiber modulator according to claim 10, wherein: The housing includes a connection port, and the second cross-section of the optical fiber interference structure receives the optical signal through the connection port.

12. A method for preparing an optical fiber interference structure, used for preparing the optical fiber interference structure in an optical fiber modulator according to any one of claims 1 to 11, characterized in that: include: staggeredly fusing the first cross section of the first optical fiber segment and one end of the connecting optical fiber segment to expose the core of the first optical fiber segment; Performing offset welding on the other end of the connecting optical fiber segment and the third section of the second optical fiber segment, so that the first section and the third section are parallel to each other, and the orthographic projection of the core of the first optical fiber segment on the plane where the third section is located is located within the range of the third section; wherein the first optical fiber segment includes the first section and the second section located on both sides of the axial direction, and a first axial plane connecting the first section and the second section; the second optical fiber segment includes the third section and the fourth section located on both sides of the axial direction, and a second axial plane connecting the third section and the fourth section; A transparent conductive layer is formed, and the transparent conductive layer covers the outer side of the connecting optical fiber segment, the first cross section, the third cross section, the second axial surface, and at least a portion of the first axial surface.

13. A light modulation device, characterized in that: The optical fiber modulator comprises the optical fiber modulator according to any one of claims 1 to 11.

14. The light modulation device according to claim 13, wherein It also includes a light source and a spectrometer, and the light source and the spectrometer are respectively connected to the second cross section of the optical fiber interference structure in the optical fiber modulator.

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