Optical fiber interference structure and preparation method thereof, optical fiber modulator and light modulation device

Abstract

The invention discloses an optical fiber interference structure, a preparation method thereof, an optical fiber modulator and a light modulation device. The optical fiber interference structure comprises a first optical fiber section which comprises a first cross section and a second cross section which are located at two axial sides, and a first axial surface which connects the first cross section and the second cross section; the second optical fiber section comprises a third cross section and a fourth cross section which are positioned on two axial sides, and a second axial surface for connecting the third cross section and the fourth cross section; one end of the connecting optical fiber section is in staggered connection with the first cross section in the radial direction, and a fiber core of the first optical fiber section is exposed; the other end of the connecting optical fiber section is connected with the third section; the transparent conductive layer coats the outer sides of the connecting optical fiber section, 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 is parallel to the third cross section, and the orthographic projection of the fiber core of the first optical fiber section on the plane where the third cross section is located is within the range of the third cross section.

Description

Technical Field

[0001] The present invention relates to but is not limited to optical modulator technology, and in particular to an optical fiber interference structure and a preparation method thereof, an optical fiber modulator and an optical modulation device. Background Art

[0002] Optical modulators can transfer modulation signals to carrier light waves, so that the parameters of the carrier light waves change with the modulation signals, and the phase, frequency, intensity and other states of the output optical signal change regularly. They are widely used in long-distance and high-speed optical communication systems. Optical modulators play an important role in scenarios such as optical information processing systems, optical interconnection 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 staggered and connected to the first section to expose 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, the fourth section has a first angle with 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.

[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 exemplary embodiment, the material of the transparent conductive layer includes indium tin oxide.

[0011] In an exemplary embodiment, 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.

[0012] In the second aspect, an embodiment of the present application provides a method for preparing an optical fiber interference structure, comprising: staggered welding a first section of a first optical fiber segment and one end of a connecting optical fiber segment to expose the core of the first optical fiber segment; staggered welding the other end of the connecting optical fiber segment and a 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 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; forming a transparent conductive layer, the transparent conductive layer coating the connecting optical fiber segment, the first section, the third section, the second axial plane, and at least part of the outside of the first axial plane.

[0013] In a third aspect, an embodiment of the present application provides a fiber optic modulator, comprising: a solution box, a DC power supply and the fiber optic interference structure as described above; wherein a liquid medium is arranged in the solution box, the liquid medium is in contact with the transparent conductive layer of the fiber optic 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 fiber optic interference structure, and the second section of the fiber optic interference structure and at least part of the transparent conductive layer are exposed to the outside of 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 fiber optic interference structure is configured to receive an optical signal, and the optical signal is modulated after passing through the fiber optic interference structure.

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

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

[0016] In an exemplary embodiment, a housing is further included, the housing surrounding the solution box and the optical fiber interference structure.

[0017] In an exemplary embodiment, 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.

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

[0019] In an exemplary embodiment, a light source and a spectrometer are further included, 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.

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

[0021] Other aspects will be apparent upon reading and understanding the drawings and detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings are used to provide an understanding of the technical solution of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present application and do not constitute a limitation on the technical solution of the present application.

[0023] Figure 1 A schematic diagram of an optical fiber interference structure provided in an embodiment of the present application;

[0024] Figure 2 for Figure 1 Sectional view along AA direction;

[0025] Figure 3 A schematic diagram of an optical fiber interference structure provided for yet another exemplary embodiment;

[0026] Figure 4 is a schematic structural diagram of an optical fiber modulator in an exemplary embodiment;

[0027] Figure 5 is a schematic structural diagram of an optical fiber modulator in yet another exemplary embodiment;

[0028] Figure 6 is a schematic structural diagram of an optical fiber modulator in yet another exemplary embodiment;

[0029] Figure 7 is a schematic structural diagram of an optical fiber modulator in yet another exemplary embodiment;

[0030] Figure 8 is a schematic structural diagram of a light modulation device in an exemplary embodiment;

[0031] Fig. 9 for Figure 8 Interference spectra of the light modulation device shown at different modulation voltages;

[0032] Fig.10 for Fig. 9 The intensity modulation fitting curve diagram of the spectral curve in ;

[0033] Fig.11 for Fig. 9 Phase modulation fitting curve of the spectral curve in . DETAILED DESCRIPTION

[0034] The present application describes multiple embodiments, but the description is exemplary rather than restrictive, and it is obvious to those skilled in the art that there may be more embodiments and implementations within the scope of the embodiments described in the present application. Although many possible feature combinations are shown in the drawings and discussed in the specific embodiments, many other combinations of the disclosed features are also possible. Unless specifically limited, any feature or element of any embodiment may be used in combination with any other feature or element in any other embodiment, or may replace 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 embodiments, features and elements disclosed in the present application may also be combined with any conventional features or elements to form a unique invention scheme. Any features or elements of any embodiment may also be combined with features or elements from other invention schemes to form another unique invention scheme. Therefore, it should be understood that any feature shown and / or discussed in the present application may be implemented individually or in any appropriate combination. Therefore, except for the limitations made according to the attached claims and their equivalents, the embodiments are not subject to other restrictions. In addition, various modifications and changes may be made within the scope of protection of the attached claims.

[0036] In addition, when describing representative embodiments, the specification may have presented the method and / or process as a specific sequence of steps. However, to the extent that the method or process does not rely on the specific order of the steps described herein, the method or process should not be limited to the steps of the specific order described. As will be understood by those of ordinary skill in the art, other sequences of steps are also possible. Therefore, the specific sequence of the steps set forth in the specification should not be interpreted as a limitation to the claims. In addition, the claims for the method and / or process should not be limited to the steps of performing them in the order written, and those skilled in the art can easily understand that these sequences can be changed and still remain within the spirit and scope of the embodiments of the present application.

[0037] The main function of a fiber modulator is to achieve optical signal conversion, which generally requires the device to have a large bandwidth, good stability, low loss, and high modulation efficiency. After the optical signal transmitted in the optical fiber passes through the modulation medium, its output amplitude, wavelength, frequency, intensity, phase, polarization state, and other states change, becoming a modulated optical signal, which is then transmitted through the optical fiber to optoelectronic devices, demodulators, and other devices to obtain the modulated signal parameters. In the entire process, the optical fiber acts as a medium to transmit and modulate light. Integrated fiber modulators have the advantages of simple control of light intensity, low insertion loss, low transmission loss, wide bandwidth, and good stability, and are used in many fields, such as electro-optical modulation systems, interference systems, and wavelength division multiplexing systems.

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

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

[0040] A 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;

[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 by the embodiment of the present application sequentially connects the first optical fiber segment, the connecting optical fiber segment and the second optical fiber segment in the axial direction, and exposes the core of the first optical fiber segment by setting the connecting optical fiber segment to be radially staggered and connected with the first optical fiber segment, and the opposite side surfaces of the first optical fiber segment and the second optical fiber segment are parallel to each other, so that a Fabry-Perot (FP) interference cavity is formed on the opposite side surfaces of the first optical fiber segment and the second optical fiber segment. The optical fiber interference structure provided by the embodiment of the present application is simple, easy to prepare and low in 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 the 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 connected in sequence along the axial direction, and a transparent conductive layer 14. Among them, the first optical fiber segment 11 includes a first section C1 and a second section C2 located on both sides of its own axial direction, and a first axial surface E1 connecting the first section C1 and the second section C2. The second optical fiber segment 13 includes a third section C3 and a fourth section C4 located on both sides of its own axial direction, and a second axial surface E2 connecting the third section C3 and the fourth section C4. One end of the connecting optical fiber segment 12 is dislocated and connected to the first section C1 in the radial direction, 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 section C3. The first section C1 and the third section C3 are parallel to each other, and the orthographic projection of the core of the first optical fiber segment 11 on the plane where the third section C3 is located is located within the range of the third section C3. The transparent conductive layer 14 is coated on the outside of the connecting optical fiber segment 12, the first section C1, the third section C3, the second axial surface E2, and at least part of the first axial surface E1. Figure 1The arrows in the figure illustrate the transmission of the light Lt in the FP interference 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 interference structure provided in the embodiment of the present application is a fiber FP interferometer structure. The fiber FP interferometer structure does not require the installation of external optical elements, has a simple structure, a smaller size, a higher degree of integration, and a low cost. It is easy to integrate with other fiber optic systems and can be flexibly applied in different scenarios. In addition, the optical path of the fiber FP interferometer structure is not a free space optical path, and the optical path alignment has better robustness and is not easily affected by factors such as temperature, humidity, vibration, air flow, and dust in the external environment. It also requires less maintenance under long-term use.

[0048] In an exemplary embodiment, the first optical fiber segment 11 may include one core. In other embodiments, the first optical fiber segment 11 may include two or more cores. Compared with the case of one core, when the first optical fiber segment 11 including two or more cores is used, the optical fiber interference structure has higher precision requirements on the size, angle and process of the components, otherwise the light is easily interfered in the FP interference cavity, affecting the light modulation effect.

[0049] In an exemplary embodiment, the first optical fiber segment 11 may be a single-mode optical fiber. Since single-mode optical fiber has a wide range of applications and is inexpensive, it helps to reduce the cost of the optical fiber interference structure provided in the embodiment of the present application and facilitates the adaptation of the optical fiber interference structure to other devices, especially devices in the communication 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 optical fiber 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, and the size of the first angle a1 may be set as required, which is not limited in the present application.

[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 may include two sections located on both sides of its own axial direction, and an axial surface connecting the two sections, the first section C1 may be connected to one of the sections of the connecting optical fiber segment 12, and the third section C3 may be connected to the other section of the connecting optical fiber segment 12. Through 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 plane, which makes it easier to connect.

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

[0056] In an exemplary embodiment, the length of the interference arm of the fiber interference structure 100 is the distance between the first section C1 and the third section C2 along the axial direction of the first fiber segment 11 , that is, the length of the connecting fiber segment 12 along the axial direction of the first 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 by 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 refractive index of the medium is related to the light transmission medium used in the FP interferometer cavity.

[0060] According to formula (1), the refractive index sensitivity in the FP interferometer cavity is independent of the length of the interferometer arm. However, the length of the interferometer arm will affect the free spectral range (FSR) of the light, and the length of the interferometer arm will affect 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 free spectral range required.

[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] It can be seen from formula (2) that the larger the length L of the interference arm, the smaller the free spectral range of the FP interferometer; the larger the refractive index n of the medium in the FP interferometer cavity, the smaller the free spectral range of the FP interferometer; the larger the wavelength λ of the incident light, the smaller the free spectral range of the FP interferometer. f When the refractive index n of the medium in the FP interference cavity and the wavelength λ of the incident light are determined, the required length L of the interference arm can be calculated according to the above formula (2), and the structural parameters of the optical fiber interference 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 , and 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 there is 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 specification, 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 center line of the connecting optical fiber segment 12 and the axial center line of the first optical fiber segment 11 along the radial direction of the first optical fiber segment 11. The indication of the second misalignment distance H2 is the same as that of the first misalignment distance H1.

[0067] In an exemplary embodiment, H1>1 / 2D1+1 / 2D2, and this setting can ensure that the first optical fiber segment 11 is completely 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 the first optical fiber segment 11 and the connecting optical fiber segment 12 are both single-mode optical fibers, the first misalignment distance H1 can be about 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 the second 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 needs and actual process conditions. With the advancement of processes and technologies, the thickness D3 of the transparent conductive layer 14 can be set smaller or larger, and the present application does not limit 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 may 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 may be approximately 2 cm, which is not limited in the present application.

[0070] In an exemplary embodiment, the material of the transparent conductive layer 14 may be indium tin oxide (ITO). The inventors of the present application have found that the use of ITO to form the transparent conductive layer 14 can maximize the effect of light transmission, while when the transparent conductive layer 14 is formed of materials such as gold (Au) and silver (Ag), even if the thickness of the transparent conductive layer 14 is thinner, the optical fiber interference structure 100 cannot achieve the desired spectral effect. In addition, ITO is used as a modulation electrode of the optical fiber interference structure, which is easy to prepare and easy to 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 source.

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

[0073] Figure 3 A schematic diagram of a fiber interference structure provided as yet another exemplary embodiment. Figure 3 and Figure 1 The difference between the two is that the coverage range of the transparent conductive layer 14 is different. The rest of the content can refer to the above description. Figure 1 The description will not be repeated here.

[0074] like Figure 3 As shown, the transparent conductive layer 14 may expose the fourth cross section C4 , and the transparent conductive layer 14 may expose a portion of the first axial surface E1 of the first optical fiber segment 11 away from the second optical fiber segment 13 . Figure 3 In the structure shown, the coverage area of ​​the transparent conductive layer 14 is smaller, which can save materials and facilitate the subsequent further packaging and adaptation of the optical fiber interference structure.

[0075] In an exemplary embodiment, the connecting optical fiber segment 12, the first optical fiber segment 11, and the second optical fiber segment 13 may be formed of optical fibers of the same specification.

[0076] The present application also provides a method for preparing an optical fiber interference structure, comprising: performing staggered welding on a first section of a first optical fiber segment and one end of a connecting optical fiber segment, and exposing the core of the first optical fiber segment; performing staggered welding on the other end of the connecting optical fiber segment and a 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; forming a transparent conductive layer, the transparent conductive layer coating the connecting optical fiber segment, the first section, the third section, the second axial plane, and at least part of the outside of the first axial plane.

[0077] The method for preparing the optical fiber interference structure provided in the embodiment of the present application adopts a large offset offset fusion splicing method to build the optical fiber FP interference structure. The connection between the optical fiber segments can be achieved only by a fusion splicer. The method is simple and convenient. In the process of offset fusion splicing 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, the forming of the transparent conductive layer includes: forming the transparent conductive layer by magnetron sputtering. 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 to form the transparent conductive layer.

[0079] In this embodiment, the transparent conductive layer is formed by a magnetron sputtering method. The preparation can be completed by using a magnetron sputtering apparatus, 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 description of the preparation process of the optical fiber interference structure in the text is used to illustrate the preparation method of the optical fiber interference structure of the present application. In this embodiment, the optical fiber used is an ordinary single-mode optical fiber purchased from Changfei Optical Fiber Company, 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 fiber segment and the third fiber segment in the fiber clamps respectively, and adjust the fusion splicing parameters in manual mode. Control the radial offset distance between the first fiber segment and the third fiber segment to be 68μm, push the fiber so that the position of the fiber fusion point is in the center of the field of view of the fusion splicer observation screen. Stop pushing when the first fiber segment and the third fiber segment just touch, and perform discharge fusion 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 optical fiber segment is cut with an optical fiber cutter under a stereo microscope to obtain a connecting optical fiber segment having an axial length of 150 μm, so that the subsequent interference arm length between the opposite side surfaces of the first optical fiber segment and the second optical fiber segment is 150 μm.

[0087] After the cutting is completed, the first optical fiber segment and the connecting optical fiber segment are taken out, and care is taken to prevent the optical fiber from breaking during the taking out process.

[0088] (3) Perform offset fusion splicing on the connecting optical fiber segment and the second optical fiber segment.

[0089] Turn on the fusion splicer, clamp the connecting fiber segment and the second fiber segment in the fiber clamps respectively, and manually adjust the positions of the connecting fiber segment and the second fiber segment so that the opposite side surfaces of the first fiber segment and the second fiber segment are completely aligned. Push the fiber so that the position of the fiber splicing point is in the center of the field of view of the fusion splicer observation screen. When the connecting fiber segment and the second fiber segment just touch, stop pushing and perform discharge splicing.

[0090] In an exemplary embodiment, during the process of aligning the relative side surfaces of the first optical fiber segment and the second optical fiber segment, the end of the first optical fiber segment away from the connected optical fiber segment can be connected to a light source and a fiber optic spectrometer, respectively, and the positions of the first optical fiber segment and the second optical fiber segment are fine-tuned according to the spectrum received by the fiber optic spectrometer. The higher the contrast of the obtained interference spectrum, the higher the degree of alignment of the relative side surfaces of the first optical fiber segment and the second optical fiber segment.

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

[0092] A first optical fiber segment and a second optical fiber segment of a longer length may be used for staggered fusion splicing. After the staggered fusion splicing is completed, the excess length is cut off to obtain an initial optical fiber interference structure of a suitable size.

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

[0094] The initial fiber interference structure is placed in the vacuum chamber of the magnetron sputtering system. By adjusting the angle between the initial fiber interference structure and the target plane, the connecting surface between the first fiber segment, the connecting fiber segment and the second fiber segment can also be sputtered to the ITO film, thereby ensuring the continuity and consistency of the ITO film in the entire interference arm area.

[0095] In an exemplary embodiment, during the sputtering process, for an ITO target, the vacuum ignition voltage may be 600 V, the continuous sputtering voltage may be 400 V, and the current may be 80 mA. By performing continuous sputtering at a relatively low voltage, the target material can be prevented from melting, ensuring a smooth coating process.

[0096] An embodiment of the present application also provides a fiber optic modulator, comprising: a solution box, a direct current power supply, and the fiber optic interference structure as described above; wherein a liquid medium is arranged in the solution box, the liquid medium is in contact with the transparent conductive layer of the fiber optic 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 fiber optic interference structure, and the second section of the fiber optic interference structure and at least part of the transparent conductive layer are exposed outside the liquid medium; one of the electrodes of the direct current power supply is connected to the liquid medium, and the other electrode of the direct current power supply is connected to 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 to change the refractive index of the liquid medium; the second section of the fiber optic interference structure is configured to receive an optical signal, and the optical signal is modulated after passing through the fiber optic interference structure.

[0097] The optical fiber modulator provided in the embodiment of the present application sets a liquid medium on the optical path between the first section and the third section of the optical fiber interference structure, applies a voltage between the transparent conductive layer of the optical fiber interference structure and the liquid medium through a DC power supply, and uses the Pockels effect of the liquid medium to change the refractive index of the liquid medium, thereby modulating the optical signal received by the second section. The optical fiber modulator provided in the embodiment of the present application has low requirements for environmental factors and helps to achieve long-term stable operation. In addition, by using the Pockels effect of the liquid medium to achieve light modulation, the light modulation process is more convenient, the modulation speed is faster, and the working efficiency of the optical modulator device is improved.

[0098] The fiber modulator provided in the embodiment of the present application can achieve specific modulation of the optical signal and obtain a specific FSR spectrum by adjusting the structural parameters of the fiber interference structure, such as the length of the interference arm. The structure of the above-mentioned fiber interference structure can be designed according to the actual required spectrum, and the present application does not limit this. After research by the inventor of the present application, there is currently no fiber interference structure 100 of the structure shown in the above-mentioned embodiment, and there is no method of combining such a fiber interference structure 100 with the Pockels effect to modulate the optical signal. The solution of the present application provides a new design idea for a fiber optic 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 fiber modulator 300 includes a solution box 110, a DC power supply 160 and a fiber interference structure 100. The solution box 110 can be located between the first section C1 and the third section C3 of the fiber interference structure 100, and surround the outside of the connecting optical fiber segment 12. A liquid medium is arranged 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. In the case where the solution box 110 is located between the first section C1 and the third section C3, the solution box 110 can be a transparent material to avoid affecting the propagation of light. The positive electrode of the DC power supply 160 can be connected to the transparent conductive layer 14 exposed outside the liquid medium, and the negative electrode of the DC power supply 160 can be connected to the liquid medium. The DC power supply 160 can excite the Pockels effect of the liquid medium after power is turned on. The second section C2 of the fiber interference structure 100 can be located outside the solution box 110, and is configured to receive external light signals. The first optical 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 optical signal is modulated into a second optical signal, and the second optical signal is emitted from the second section C2. Since the refractive index of the liquid medium changes under the Pockels effect, the first optical signal from the outside can be modulated into a second optical signal. When the first optical signal is continuously incident, the optical fiber modulator 300 can continuously output the second optical signal to the outside. When the structure of the optical fiber interference structure 100 is fixed, the modulation effect of 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 spectrum of the required second optical 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, if Figure 4As shown, a conductive column 111 may be provided in the solution box 110, one end of the conductive column 111 may extend into the liquid medium, the other end of the conductive column 111 may be fixed to the inner surface of the solution box 110, and contact with a first electrode sheet (not shown) provided on the outer surface of the solution box 110, and one of the electrodes of the DC power supply 160 may be connected to the first electrode sheet to provide a voltage signal to the liquid medium. In an exemplary embodiment, the conductive column 111 and the first electrode sheet may be an integral structure.

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

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

[0104] In an exemplary embodiment, the DC power supply 160 is a detachable structure, which is convenient for subsequent replacement.

[0105] In an exemplary embodiment, the liquid medium in the solution box 110 can be a liquid or solution that can produce the Pockels effect in 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 and non-toxic, has good stability, is 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, disulfur dichloride, sulfuryl chloride, arsenic trichloride, silicon hydrogen chloride, sulfuric acid, nitric acid, phosphoric acid, liquid ammonia, anhydrous perchloric acid, etc., and a suitable liquid medium can be selected as needed, and this application is not limited to 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 acts as an electrode and 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 FP interference cavity. There is an electric double layer (EDL) at the interface between the transparent conductive layer 14 and 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 leading to the orientation order of water molecules. Under the action of the external electric field, the spatial distribution of water molecules in the electric double layer changes, resulting in a change in the effective refractive index (RI) of water near the transparent conductive layer 14.

[0107] In an exemplary embodiment, Figure 4 As shown, the optical fiber modulator 300 may also include a housing 200, which may surround the solution box 110 and the outside of the optical fiber interference structure 100, and may play a protective role to prevent the optical fiber modulator 300 from being damaged by external forces during transportation or use. The DC power supply 160 may be arranged inside the housing 200, and the protective effect is better. Alternatively, the housing 200 may have a power supply accommodation space (not shown), and the DC power supply 160 may be installed in the power supply accommodation space. The DC power supply 160 may be connected to the first electrode sheet 111 and the second electrode sheet 112 in the power supply accommodation space. When the DC power supply 160 needs to be replaced later, the replacement can be completed without disassembling the housing 200, which is convenient for maintenance. A cover plate (not shown) may be provided outside the power supply accommodation space to facilitate the protection of the DC power supply 160 located in the power supply accommodation space.

[0108] In an exemplary embodiment, Figure 4 As shown, the housing 200 further includes a connection port 201, which is disposed outside the second section C2. External optical fibers and other structures can be connected to the core of the second section C2 through the connection port 201, so as to provide a first optical signal to the optical fiber modulator 300. The connection port 201 is provided to facilitate the connection of the optical fiber modulator 300 with the outside.

[0109] exist Figure 4 In the structure shown, the solution box 110 is relatively small in size, which helps to save costs and facilitates connection with the fiber optic interference structure 100.

[0110] Figure 5 It is a schematic structural diagram of a fiber optic modulator in yet another exemplary embodiment. Figure 5 and Figure 4 The difference lies in the shape of the solution box 110 and the shape of the housing 200. The remaining structures can refer to the above description. Figure 4 The description will not be repeated here.

[0111] like Figure 5 As shown, the first section C1, the third section C3 and at least part of the connecting fiber segment 12 along the radial direction of the first fiber segment 11 of the optical fiber interference structure 100 are immersed in the liquid medium. The solution box 110 surrounds the partial surface of the first cylindrical surface E1 and the second cylindrical surface E2, wraps the FP cavity between the first section C1 and the third section C3 in the liquid medium, and can expose the side of the connecting fiber segment 12 away from the first fiber segment 11 and the second fiber segment 13. In the case where the solution box 110 wraps the FP cavity in the liquid medium, the solution box 110 can be made of opaque material.

[0112] In an exemplary embodiment, Figure 5 As shown, the second section C2 of the optical fiber interference structure 100 can be exposed outside the shell 200, and no connection port is set on the shell 200. The fiber core of the second section C2 can be directly connected to external optical fiber structures.

[0113] exist Figure 5 In the structure shown, the solution box 110 surrounds the first section C1, the third section C3 and the outer side of the at least partially connected optical fiber segment 12 along the radial direction of the first optical fiber segment 11 of the optical fiber interference structure 100. There is no surface of the solution box 110 between the first section C1 and the third section C3, and the loss of light in the process of passing through the FP interference cavity is smaller, which helps to improve the light modulation effect.

[0114] Figure 6 It is a schematic structural diagram of a fiber optic modulator in yet another exemplary embodiment. Figure 6 and Figure 5 The difference is the shape of the solution box 110, and the rest of the structure can refer to the above Figure 5 The description will not be repeated here.

[0115] like Figure 6 As shown, the solution box 110 may be in a "U" shape. Figure 5 The first optical signal in the solution box 110 does not pass through the air and the outer surface of the solution box 110, but Figure 6 In the process of passing through the solution box 110, the first light signal needs to pass through a section of air path and needs to pass through the outer surface of the solution box 110. In the shell of the solution box 110, at least the shell located near the optical path of the first light signal is made of 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] exist Figure 6 In the structure, the shape design of the solution box 110 is more flexible. Setting the outer surface of the solution box 110 to different shapes helps to adapt the shapes of the solution box 110 and the optical fiber interference structure 100 to facilitate disassembly and assembly.

[0117] Figure 7 FIG. 4 is a schematic diagram of the structure of an optical fiber modulator in another exemplary embodiment. Figure 7As shown, the solution box 110 can be wrapped around the outside of the second optical fiber segment 13, the connecting optical fiber segment 12 and part of the first optical fiber segment 11. The transparent conductive layer 14 of the optical fiber interference structure 100 can expose the fourth section C4 and part of the first axial surface E1 of the first optical fiber segment 11 away from the second optical fiber segment 13. One of the electrodes of the DC power supply 160 can directly extend into the liquid medium, and the other electrode of the DC power supply 160 can be directly connected to the exposed transparent conductive layer 14. The transparent conductive layer 14 of the optical fiber interference structure 100 can be located in the housing 200, and the second section C2 of the optical fiber interference structure 100 can be exposed outside the housing 200.

[0118] Figure 7 The rest of the structure can refer to the above Figures 4 to 6 The description will not be repeated here.

[0119] exist Figure 7 In the structure, the solution box 110 is larger in size and the immersion range of the liquid medium is larger, which not only facilitates the modulation of the light, but also helps to protect the optical fiber interference structure 100 and maintain the structural stability of the optical fiber modulator 300, and the dimensional accuracy requirements of the solution box 110 are relatively small.

[0120] In an exemplary embodiment, Figures 4 to 7 The structures in the embodiment can be combined with each other arbitrarily, and this application does not impose any limitation on this.

[0121] An embodiment of the present application also provides an optical modulation device, including the optical fiber modulator as described above.

[0122] The optical modulation device provided in the embodiment of the present application, when applied to the field of optical fiber sensing, the above-mentioned optical fiber modulator can be used as a sensing probe, and when applied to the field of electrochemistry, the above-mentioned optical fiber modulator can be used as a working electrode. The optical modulation device may also include an optical switch, and the above-mentioned optical fiber modulator can realize the function of the optical switch. The optical 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 an exemplary embodiment, the optical modulation device includes a light source, a spectrometer, and the optical fiber modulator as described above, wherein the light source and the spectrometer are respectively connected to the second cross section of the optical fiber modulator. The optical modulation device provided in the embodiment of the present application has a simple structure, is easy to prepare, and is safe and reliable, and is suitable for popularization and use.

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

[0125] The inventors of this application Figure 8 The optical modulation device shown was tested. During the test, the first optical signal from the light source 130 reached the optical fiber modulator 300 via the transmission optical fiber 120, and formed a second optical signal after being modulated by the optical fiber modulator 300. The spectrometer 140 can detect the spectrum of the second optical signal. The interference spectrum of the second optical signal under different applied voltages was tested. In the test, the coupler 150 used a wavelength division multiplexing coupler purchased from Changfei Optical Fiber Company; as a phase-shift control power supply, the DC power supply 160 used a voltage-stabilized DC power supply purchased from Yangzhou Huatai Electronics Co., Ltd.; the light source 130 used an ASE light source purchased from Chengdu Lifeng Technology Co., Ltd. As an optical signal detector, the spectrometer 140 used a fiber spectrometer (Yokogawa AQ-6317B) purchased from the Guangzhao Technology R&D Center.

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

[0127] Fig.10 for Fig. 9 Intensity modulation fitting curve of the spectral curve in . Fig.10 The horizontal axis is voltage, the unit is V, and the vertical axis is intensity, the unit is decibel milliwatt (dBm). Fig.10The discrete points in the figure represent the intensity corresponding to the test voltage value. The ordinate is y and the abscissa is x. After performing intensity modulation fitting, we get y = -6.0327x - 61.5731. The fitting coefficient R 2 is 0.9971. Fig.10 It can be seen that the fitting relationship shows a good linear range, which is helpful for calibration in practical applications.

[0128] Fig.11 for Fig. 9 Phase modulation fitting curve of the spectral curve in . Fig.11 The horizontal axis is voltage, the unit is V, and the vertical axis is wavelength, the unit is nanometer. Fig.11 The discrete points in the figure represent the wavelength corresponding to the test voltage value. The ordinate is y and the abscissa is x. After intensity modulation fitting, we get y=1.1789+1534.6909x. The fitting coefficient R 2 is 0.9909. Fig.11 It can be seen that the fitting relationship shows a good linear range, which is helpful for calibration in practical applications.

[0129] Combination Figures 9 to 11 It can be seen that compared with light modulator devices in other technologies, the light modulator device provided in the embodiment of the present application has a better spectral modulation effect.

[0130] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0131] In addition, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include at least one of the features.

[0132] In the description of the present application, “plurality” means at least two, for example, two, three, etc., unless otherwise clearly and specifically defined.

[0133] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed", etc. should be understood in a broad sense. For example, "connected" 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 an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0134] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0135] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification 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 can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A fiber interference structure, characterized in that: include: A 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.

2. The optical fiber interference structure according to claim 1, characterized in that: 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 to the fourth section.

3. The optical fiber interference structure according to claim 2, characterized in that: The first optical fiber segment includes at least one optical fiber core.

4. The optical fiber interference structure according to claim 3, characterized in that: The first optical fiber segment is a single-mode optical fiber.

5. The optical fiber interference structure according to claim 2, characterized in that: 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 interference structure according to claim 2, characterized in that: The material of the transparent conductive layer includes indium tin oxide.

7. The optical fiber interference structure according to claim 6, characterized in that: 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. A method for preparing an optical fiber interference structure, characterized in that: include: Performing offset fusion splicing on the first cross section of the first optical fiber segment and one end of the connecting optical fiber segment, and exposing the core of the first optical fiber segment; The other end of the connecting optical fiber segment and the third section of the second optical fiber segment are staggered and fused, 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, wherein 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.

9. An optical fiber modulator, characterized in that: include: A solution box, a DC power supply and an optical fiber interference structure as described in any one of claims 1 to 7; wherein a liquid medium is arranged in the solution box, 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.

10. The optical fiber modulator according to claim 9, characterized in that: The liquid medium in the solution box is a polar liquid or solution.

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

12. The optical fiber modulator according to claim 9, characterized in that: The invention also includes a housing, which surrounds the solution box and the optical fiber interference structure.

13. The optical fiber modulator according to claim 12, characterized in that: The housing comprises a connection port, and the second cross section of the optical fiber interference structure receives the optical signal through the connection port.

14. A light modulation device, characterized in that: Comprising the optical fiber modulator as claimed in any one of claims 9 to 13.

15. The light modulation device according to claim 14, characterized in that: It also includes a light source and a spectrometer, wherein 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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