Light beam splitting structure

Abstract

The utility model provides a light beam splitting structure which comprises an optical waveguide which is provided with a light input end and a light output end, at least one light leakage area is arranged on the portion between the light input end and the light output end, and each light leakage area is used for leaking out part of light transmitted in the optical waveguide. Therefore, light splitting is achieved, the light splitting structure is greatly simplified, the size of the optical waveguide is small, the size and the position of a micron-sized light leakage area can be flexibly adjusted according to needs, and application of the optical waveguide in integrated and miniaturized sensors can be achieved. The light leakage area is filled with the filler with the set refractive index or the adjustable refractive index, so that the collection efficiency or the light emitting proportion of the leaked light is regulated and controlled by changing the light refractive index, and flexible regulation and control of the light intensity are achieved.

Description

Technical Field

[0001] This utility model relates to the field of optical sensing, and in particular to a light beam splitting structure. Background Technology

[0002] In the field of optical sensing, such as quantum sensors, existing technologies for beam splitting light often employ beam splitters or fiber optic beam splitters. However, these beam splitters and beam splitters are relatively large, making them unsuitable for miniaturized, highly integrated sensors. When using beam splitters, to prevent interference between the split beams, a longer transmission distance is required for spatial light transmission, increasing the space occupied by the optical path. Even with fiber optic transmission, a fixed structure is needed at the beam splitter to facilitate light coupling into the fiber, further increasing the size and flexibility of the optical path structure. While fiber optic beam splitters offer relative flexibility, they still require significant space and necessitate guiding the light into the splitting fiber for separation. Furthermore, light propagation within the splitting fiber increases noise and reduces stability.

[0003] Simplifying the optical beam splitter structure has become a technical problem that needs to be solved. Utility Model Content

[0004] In view of the shortcomings of the prior art described above, the purpose of this utility model is to provide an optical beam splitting structure to solve the problem that the optical beam splitting structure occupies a large space and is not conducive to its application in miniaturized sensors.

[0005] To achieve the above and other related objectives, the present invention provides an optical beam splitter structure, comprising: an optical waveguide having an optical input end and an optical output end, and having at least one light leakage region disposed on the portion located between the optical input end and the optical output end, each light leakage region being used to leak out a portion of the light transmitted in the optical waveguide.

[0006] Furthermore, the light leakage area is formed by changing the shape of the core layer and cladding interface, or by exposing at least a portion of the cladding cross-section to the outside, or by exposing the outer surface of the core layer to the outside, or by exposing at least a portion of the core layer cross-section to the outside.

[0007] Furthermore, when the light leakage region is formed by changing the shape of the core layer and cladding interface, the shape is changed to an hourglass shape or a cone shape.

[0008] Furthermore, a light-focusing structure is provided at the light leakage area and / or the light output end to focus the emitted light.

[0009] Furthermore, the light-concentrating structure is a light-concentrating lens.

[0010] Furthermore, the light-concentrating structure is a cavity structure with an opening, and the cavity wall of the cavity structure is configured to reflect light incident thereon.

[0011] Furthermore, the light leakage area is filled with a filler having a set refractive index.

[0012] Furthermore, the refractive index of the filler changes with temperature, and a temperature control device is provided to regulate the temperature of the filler.

[0013] Furthermore, the filler is one of water, glycerin, ethanol, methanol, liquid paraffin, vegetable oil, polydimethylsiloxane, and optical adhesive.

[0014] Furthermore, the light-leaking area filled with filler is located in a closed cavity, and the closed cavity is made of a light-transmitting material.

[0015] As described above, the optical beam splitting structure of this invention has the following beneficial effects:

[0016] 1. By setting at least one light leakage region between the optical input end and the optical output end of the optical waveguide, a portion of the light transmitted in the optical waveguide leaks out through each light leakage region, thereby realizing light beam splitting. This greatly simplifies the optical beam splitting structure. Furthermore, the size of the optical waveguide is small, generally in the micrometer range, and the size and position of the light leakage region can be flexibly adjusted as needed, enabling its application in integrated and miniaturized sensors.

[0017] 2. Fill the light leakage area with a filler having a set refractive index or an adjustable refractive index, and then adjust the collection efficiency or emission ratio of the leaked light by changing the light refractive index, thereby achieving flexible control of the light intensity. Attached Figure Description

[0018] Figure 1 The diagram shown is a first structural schematic of the optical beam splitter structure of this utility model.

[0019] Figure 2 The diagram shown is a second structural schematic of the optical beam splitter structure of this utility model.

[0020] Figure 3 The diagram shown is a third structural schematic of the optical beam splitter structure of this utility model.

[0021] Figure 4 The diagram shown is a structural schematic of the closed cavity of this utility model;

[0022] Figure 5 This is a schematic diagram of the fourth structure of the optical beam splitter structure of this utility model;

[0023] Figure 6This is a schematic diagram of the fifth structure of the optical beam splitter structure of this utility model;

[0024] Figure 7 This is a schematic diagram of the sixth structure of the optical beam splitter structure of this utility model;

[0025] Figure 8 This is a schematic diagram of the seventh structure of the optical beam splitter structure of this utility model.

[0026] Component labeling: 1—Optical waveguide; 11—Optical input terminal; 12—Optical output terminal; 13—Light leakage area; 131—Filling material; 14—Concentrating structure; 15—Sealed cavity; 151—Sealed area; 152—Filling hole; 16—Temperature control; 17—Core layer; 18—Cladding layer; 19—Coating layer. Detailed Implementation

[0027] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0028] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the illustrations only show the components related to the present invention and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0029] Example 1: As Figure 1 As shown, this embodiment provides an optical beam splitter structure, including: an optical waveguide 1 having an optical input end 11 and an optical output end 12, and at least one light leakage region 13 is provided on the portion located between the optical input end 11 and the optical output end 12, each light leakage region being used to leak out a portion of the light transmitted in the optical waveguide.

[0030] Figure 1 An example is given of a light leak area; the case of multiple light leak areas is as follows: Figure 2 As shown, the structures of the light leakage regions can be identical or different, and they are arranged along the axis of the optical waveguide.

[0031] Thus, optical beam splitting is achieved, with the split light output from the optical output end and at least one light leakage region. This embodiment uses only an optical waveguide to achieve beam splitting, greatly simplifying the optical beam splitting structure. Furthermore, the optical waveguide is small in size, generally in the micrometer range, and the size and position of the light leakage region can be flexibly adjusted as needed, enabling its application in integrated and miniaturized sensors.

[0032] For a typical optical waveguide, from the inside out, it includes a core layer 17 and a cladding layer 18. The outer surface of the core layer can be completely covered by the cladding layer. Examples include columnar optical fibers and embedded strip waveguides. It can also have a layered structure, such as a planar waveguide with a core layer in the middle and cladding layers on the top and bottom, or a strip waveguide with the core layer embedded within the cladding layer or located on the surface of the cladding layer. Optical fibers can be further divided into bare fibers and fibers with protective layers. For bare fibers, a coating layer is applied to the outside of the cladding layer, while for fibers with protective layers, a protective layer covers the outside of the cladding layer. Figure 1 The example shown is a bare optical fiber including a coating layer 19. Regardless of the type of optical waveguide, the principle of light transmission within it is the same: light propagates in the core layer and undergoes total internal reflection at the interface between the core and cladding, preventing light leakage. In this embodiment, a light leakage region is provided between the optical input and output ends to allow some of the light propagating in the waveguide to leak out, thus achieving light splitting. The optical fiber in this embodiment can be single-mode or dual-mode fiber.

[0033] In this embodiment, a section of the optical waveguide is processed to change the shape of the core-cladding interface in the waveguide section where the leakage region is located. This alters the incident angle of light at the core-cladding interface in this section, thereby changing the total internal reflection condition and allowing light to leak out from the cladding. For example, in optical fiber, the area to be processed can be heated and stretched to change the incident angle of light at the core-cladding interface, thus changing the total internal reflection condition and allowing some light in the core to leak out. Figure 1 After the optical fiber is stretched, the light leakage area is hourglass-shaped. Figure 1 The example illustrates first removing the outer layer of the part to be processed, such as a coating or protective layer. Removal methods include scraping, peeling, polishing, or heating. Then, stretching is performed to achieve a better light leakage effect. For example... Figure 1 After being stretched, the optical fiber in the waveguide exhibits an hourglass-shaped leakage region. Different leakage intensities can be obtained by selecting different stretching lengths. Alternatively, the shape of the core-cladding interface of the waveguide segment containing the leakage region can be altered during the waveguide forming stage; for example, the cladding-core interface of the leakage region can be shaped like an hourglass or similar design. Figure 8 The cone shape shown is an example.

[0034] Alternatively, after the cladding is exposed to the outside, at least part of the cladding can be removed so that some of the light entering the cladding can leak out. This method may result in less leaked light and is more suitable for situations where the required light intensity is weak.

[0035] In this embodiment, the setting of the light leakage region not only simplifies the beam splitting structure, but also allows the light propagating in the optical waveguide to be directly separated from the light leakage region, without the need to introduce the beam splitting fiber for separation as in an optical fiber beam splitter. This can effectively reduce noise and improve stability.

[0036] To increase the collection of light leakage in the leakage region and minimize its size, this embodiment employs methods such as stretching the optical fiber to allow light to leak out and obtain the desired leakage light intensity. This places certain requirements on the stretching length of the optical fiber; a larger stretching length is needed for the required light intensity, but because the optical fiber is relatively thin, excessive stretching can easily lead to breakage. Therefore, it is possible to... Figure 2 As shown, filler 131 is filled in the light leakage area. The filler has a set refractive index to change the original refractive index, increase the collection efficiency of leaked light, or improve the light emission ratio. Furthermore, by adjusting the size of the filler, the size and light leakage efficiency of the light leakage area can be flexibly controlled. The formation of the filler acts similarly to an optical lens. Different refractive indices of the filler result in different light collection effects or light emission ratios. Fillers with higher refractive indices can be selected, such as optical adhesives, UV-curable adhesives, or PDMS (polydimethylsiloxane). Liquids such as water and glycerin can also be used. For liquid fillers, [the following is an example / example] can be used. Figure 3 The enclosed cavity 15 shown seals off the light leakage area. The shape of the filler is configured to converge light, for example, as a lens structure with a convex surface.

[0037] Example 2: In this example, a section of the optical waveguide is processed to expose the outer surface of the core layer. For example, for optical fibers, this can be done by scraping, stripping, or polishing; for other types of waveguides, the cladding is removed during the forming stage using processes such as etching. Figure 2 As shown, after removing the cladding, some light in the core layer is refracted out, forming a light leakage region. In this embodiment, it can also be done as follows... Figure 3 As shown, the core layer is further partially removed so that at least a portion of the core layer's cross-section is exposed to the outside.

[0038] In this embodiment, a light-focusing structure 14 is provided in at least one light-leaking area and / or light output end to focus the emitted light.

[0039] The focusing structure 14 can be a focusing lens, and the light leakage area or light output end can be at least partially located inside the focusing lens. The focusing lens can be, for example, Figure 2 , Figure 4 , Figure 7 The TIR lens (i.e., a total internal reflection lens) shown has an incident surface that is a groove recessed into the lens body (e.g., Figure 4The area marked with a dashed line (in the middle) can be at least partially positioned within the recess of the TIR lens (e.g., the light leakage area or the light output end). Figure 2 The light waveguide can be inserted or slotted into the sidewall of the groove or the lens body (only the hole or slot structure inside the TIR lens is shown in the figure), so that the light leakage area or the light output end is partially or completely located inside the groove or the lens body; alternatively, the groove of the TIR lens can be directly aligned with the filler 131, and the filler 131 can be built into the groove of the lens; or the light leakage area or the light output end can be housed in the lens body, making it an integral structure with the lens. The TIR lens performs total internal reflection to focus the light, and emits it from the other end face to achieve the collection of the light beam or to obtain the light of the required intensity. Other lenses can also be used, such as Figure 8 The hemispherical lens shown Figure 3 The compound parabolic condenser and aspherical lens shown can all converge light. Slots or perforations can be made in these lenses to place the light leakage area or light output end inside the lens; alternatively, the light leakage area or light output end can be housed within the condenser lens, forming an integral structure with the condenser lens. Of course, the light leakage area or light output end can also be located outside the condenser lens, as exemplified by... Figure 4 , Figure 7 As shown, light is refracted from the external space and focused into the condenser lens.

[0040] Concentrating structures can also be like Figure 5 As shown, this is a cavity structure with an opening, where the light leakage area or light output end is located within the cavity structure. The cavity can be made of metal, with the inner wall reflecting light and allowing it to exit through the opening to achieve light focusing; alternatively, the cavity can be made of non-metallic material, with the inner wall covered by a light-reflecting film to reflect light and allow it to exit through the opening. The light-reflecting film can be a metallic film or a non-metallic high-reflectivity film, such as titanium dioxide, zinc oxide, or other metal oxide materials.

[0041] To enhance the adjustability of the leaked light intensity, the filler 131 filling the leaking area is made of a substance whose refractive index changes with temperature, such as water, glycerin, ethanol, methanol, liquid paraffin, vegetable oil (e.g., linseed oil), PDMS (polydimethylsiloxane), optical adhesive, etc. For liquid fillers, a sealed cavity 15 can be used to seal the leaking area. Temperature control devices 16, such as semiconductor cooling chips, non-metallic heating elements, or thermally conductive metal materials, are installed inside or outside the sealed cavity to regulate the temperature of the filler, thereby obtaining the required light output and maintaining light output stability. Figure 3As shown, a temperature control unit 16 is set outside the sealed cavity and located on the side of the optical waveguide opposite to the light leakage area. By adjusting the temperature of the temperature control unit 16, the refractive index of the filling liquid changes, thereby adjusting the light emission ratio of the light leakage area and thus regulating the intensity of the leaked light. For solid fillers, a sealed cavity can be selectively added or omitted. For example, cured PDMS is filled in the light leakage area in solid form by filling the light leakage area with PDMS solution and then curing it at high temperature.

[0042] In this embodiment, the enclosed cavity can be made of a light-transmitting material, such as glass or other materials with low self-fluorescence and high light transmittance. After the optical waveguide is inserted into the cavity, it is sealed by sealing the gaps at both ends of the cavity with adhesive. Figure 3 The sealing area 151 is filled with liquid, and the liquid is injected into the light leakage area in the middle of the cavity through the sealing area by an extremely fine injection needle. The sealed cavity after filling with liquid can be sealed again to improve the sealing performance.

[0043] It is also possible to do as Figure 4 As shown, a filling hole 152 is opened on the wall surface of the sealed cavity near the light leakage area. After the sealed cavity is closed, filling liquid is injected into the light leakage area inside the cavity through the filling hole 152. After filling, the filling hole can be sealed with adhesive. Figure 4 The example provided shows a temperature control unit 16 installed in a sealed cavity, facilitating the placement of the entire sealed cavity within a condenser lens. The temperature control unit can employ the aforementioned structure, or it can be made of a smaller heat-conducting wire or strip and connected to an external cooling or heat dissipation device. Alternatively, a semiconductor temperature control layer can be deposited directly on the inner wall of the sealed cavity and connected to an external cooling or heat dissipation device. A spacer can also be provided between the temperature control unit and the optical waveguide to prevent the filling liquid from seeping into the temperature control unit.

[0044] Example 3: In this example, by cutting or misaligning the optical waveguide, at least a portion of the core layer cross-section is exposed to the outside, thereby forming a light leakage region 13. For example... Figures 5-6 As shown, this represents the exposed portion of the core layer cross-section of the optical waveguide. Figure 5 The method of partial truncation is adopted. Figure 6 The two optical waveguide ends are staggered and connected, and the connection method can be direct contact or fusion welding. Figure 7 As shown, the entire core cross-section is exposed to the outside.

[0045] The light leakage area in this embodiment can also be treated with the filling material as in Embodiment 1 or 2, which will not be described in detail here.

[0046] Figure 6This is a top view taken from the condenser lens side. Through misalignment, a portion of the core layer's cross-section is aligned with a portion of the cladding's cross-section, allowing some light from the core layer to enter the cladding and then leak out.

[0047] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A beam splitter structure, characterized in that, The structure includes: an optical waveguide having an optical input end and an optical output end, and at least one light leakage region is provided on the portion located between the optical input end and the optical output end, each light leakage region being used to leak out a portion of the light transmitted in the optical waveguide.

2. The optical beam splitter structure according to claim 1, characterized in that: The light leakage area is formed by changing the shape of the core layer and cladding interface, or by exposing at least a portion of the cladding cross-section to the outside, or by exposing the outer surface of the core layer to the outside, or by exposing at least a portion of the core layer cross-section to the outside.

3. The optical beam splitter structure according to claim 2, characterized in that: When the light leakage region is formed by changing the shape of the interface between the core layer and the cladding layer, the shape is changed to an hourglass shape or a cone shape.

4. The optical beam splitter structure according to claim 1, characterized in that: A light-focusing structure is provided at the light leakage area and / or the light output end to focus the emitted light.

5. The optical beam splitter structure according to claim 4, characterized in that: The light-concentrating structure is a light-concentrating lens.

6. The optical beam splitter structure according to claim 4, characterized in that: The light-concentrating structure is a cavity structure with an opening, and the cavity wall of the cavity structure is configured to reflect light incident thereon.

7. The optical beam splitter structure according to claim 1, characterized in that: The light leakage area is filled with a filler having a set refractive index.

8. The optical beam splitter structure according to claim 7, characterized in that: The refractive index of the filler changes with temperature, and a temperature control device is provided to regulate the temperature of the filler.

9. The optical beam splitter structure according to claim 8, characterized in that: The filler is one of water, glycerin, ethanol, methanol, liquid paraffin, vegetable oil, polydimethylsiloxane, or optical adhesive.

10. The optical beam splitter structure according to any one of claims 7-9, characterized in that: The light-leaking area filled with filler is located in a closed cavity, which is made of a light-transmitting material.

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