Temperature sensor
By employing a fixed-connection sleeve and reflective component design in the temperature sensor, combined with materials and protective structures of different thermal expansion coefficients, the problems of unstable optical signals and high processing difficulty were solved, achieving stable optical signal transmission and efficient processing, and improving the sensitivity and consistency of the temperature sensor.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-03
- Publication Date
- 2026-03-10
AI Technical Summary
Existing Fabry-Perot cavity temperature sensors suffer from unstable optical signals, high manufacturing difficulty, and low efficiency.
A temperature sensor was designed, comprising a first sleeve, a light incident end, and a reflective component, which are fixedly connected by adhesive or laser welding to form a Fabry-Perot cavity. Materials with different coefficients of thermal expansion are used to improve sensitivity, and a protective sleeve and sealant are set on the outside to enhance stability and ease of processing.
It achieves stable optical signal transmission and is easy to process, improving processing efficiency, reducing costs, and enhancing the sensitivity and consistency of temperature sensors.
Smart Images
Figure CN223985793U_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to a temperature sensor. Background Technology
[0002] Existing Fabry-Perot (FP) cavity temperature sensors consist of an incident optical fiber inserted into a capillary tube and a reflecting optical fiber forming an FP cavity at the gap. Existing temperature sensors have the following problems: on the one hand, they cannot receive a stable optical signal or the received optical signal is weak; on the other hand, temperature sensors are not easy to manufacture and have low manufacturing efficiency. Summary of the Invention
[0003] Therefore, the object of this disclosure is to provide a temperature sensor that is easy to manufacture and can transmit stable optical signals.
[0004] The above objective is achieved by means of a temperature sensor as described below.
[0005] This disclosure provides a temperature sensor, comprising: a first sleeve; a light incident end located at least partially within the first sleeve; and a reflective member located at least partially within the first sleeve, the reflective member being configured to be disposed opposite to the light incident end, the end face of the light incident end and the end face of the reflective member forming a Fabry-Perot cavity; the light incident end and the reflective member being fixedly connected to the first sleeve respectively.
[0006] In one embodiment, the light incident end is an incident optical fiber, which is inserted into the first sleeve.
[0007] In one embodiment, the end face of the first sleeve is bonded to the outer surface of the incident optical fiber.
[0008] In one embodiment, the reflective component is a reflective optical fiber or a reflective rod.
[0009] In one embodiment, the light incident end includes an incident optical fiber and a second sleeve sleeved outside the incident optical fiber, the second sleeve being inserted into the first sleeve.
[0010] In one embodiment, the end of the second sleeve is recessed inward relative to the end of the first sleeve, and the inner surface of the end of the first sleeve is bonded to the end face of the second sleeve.
[0011] In one embodiment, the sum of the difference between the first and second thermal expansion coefficients is greater than 2 * 10. -6 / ℃, the first thermal expansion coefficient difference is the difference between the thermal expansion coefficients of the first sleeve and the light incident end, and the second thermal expansion coefficient difference is the difference between the thermal expansion coefficients of the first sleeve and the reflective component.
[0012] In one embodiment, the material of the first sleeve and the reflective member is selected from one of the following: metal, ceramic, or glass.
[0013] In one embodiment, the length of the Fabry-Perot cavity is 10-30 μm.
[0014] In one embodiment, it further includes: a protective sleeve disposed outside the first sleeve and a sealant disposed at the end of the protective sleeve.
[0015] The temperature sensor of this application can receive a stable light signal and is easy to manufacture with high processing efficiency. Attached Figure Description
[0016] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings of the embodiments of this disclosure will be briefly described below. The drawings are merely illustrative of some embodiments of this disclosure and are not intended to limit the scope of all embodiments of this disclosure. In the drawings:
[0017] Figure 1 A schematic diagram of a temperature sensor comprising a reflective optical fiber and a third sleeve according to a first embodiment of the present disclosure is shown.
[0018] Figure 2 A schematic diagram of a temperature sensor including an adhesive portion according to a first embodiment of the present disclosure is shown;
[0019] Figure 3 A schematic diagram of a temperature sensor including an adhesive portion according to a first embodiment of the present disclosure is shown;
[0020] Figure 4 A schematic diagram of a temperature sensor with a solid rod as the reflective member according to a first embodiment of the present disclosure is shown.
[0021] Figure 5 A schematic diagram of a temperature sensor including an adhesive portion according to a first embodiment of the present disclosure is shown;
[0022] Figure 6 A schematic diagram of a temperature sensor including a housing according to a first embodiment of the present disclosure is shown;
[0023] Figure 7 A schematic diagram of a temperature sensor with an incident optical fiber as the light incident end, according to a second embodiment of the present disclosure, is shown.
[0024] 1. Incident fiber 2. Second sleeve 3. First sleeve 4. End face of light incident end 5. Fabry-Perot cavity 6. End face of reflecting component 7. Third sleeve 8. Reflecting fiber 9. Solid rod 10. Adhesive part 12. Protective sleeve 13. Thermal grease 14. Sealant 15. Pigtail protective sleeve 16. Fiber optic connector Detailed Implementation
[0025] To make the objectives, technical solutions, and advantages of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. The same reference numerals in the drawings represent the same components. It should be noted that the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.
[0026] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an” or “a” and similar terms do not necessarily indicate a quantity limitation. The terms “comprising,” “including,” or “having,” and similar terms mean that the element or object preceding the word encompasses the element or object listed following the word and its equivalents, without excluding other elements or objects. The terms “connected” or “connected,” and similar terms are not limited to the physical or mechanical connection or connection shown in the drawings, but may include equivalent connections or connections, whether direct or indirect. The terms “upper,” “lower,” “left,” and “right,” etc., are used only to indicate relative positional relationships, which may change accordingly when the absolute position of the described object changes.
[0027] Figures 1 to 5 A schematic diagram of a temperature sensor according to a first embodiment of the present disclosure is shown. The temperature sensor includes: a first sleeve 3; a light incident end located at least partially within the first sleeve 3, the light incident end including an incident optical fiber 1 and a second sleeve 2 disposed outside the incident optical fiber 1, the light incident end being cut to form an end face 4 perpendicular to the incident optical fiber 1; a reflective member located at least partially within the first sleeve 3, the reflective member being configured to be disposed opposite to the incident optical fiber 1, the end face 4 of the light incident end and the end face 6 of the reflective member forming a Fabry-Perot cavity 5; and an adhesive portion 10 for fixing the first sleeve 3 to the second sleeve 2 and the reflective member respectively.
[0028] The temperature sensor disclosed herein is not only easy to manufacture, improving manufacturing efficiency and reducing manufacturing costs, but also capable of outputting a stable optical signal.
[0029] In one embodiment of this disclosure, the adhesive portion 10 fixes the two ends of the first sleeve 3 to the second sleeve 2 and the reflective member, respectively. The ends of the first sleeve 3 can be connected to the second sleeve 2 and the reflective member by adhesive or laser welding. The adhesive portion 10 can be an adhesive or solder. Optionally, the adhesive portion 10 fixes the end face of the first sleeve 3 to the outer surface of the second sleeve 2 or the outer surface of the reflective member (e.g., ...). Figure 2 (as shown); or, the adhesive part 10 fixes the inner surface of the end of the first sleeve 3 to the end face of the second sleeve 2 or the end face 6 of the reflective member (as shown). Figure 3 (As shown).
[0030] For example, the first adhesive part fixes the end face of the first end of the first sleeve 3 to the outer surface of the second sleeve 2, and the second adhesive part fixes the inner surface of the second end of the first sleeve 3 to the end of the reflective member. The first end is the end of the second sleeve 2. For example, the first adhesive part fixes the inner surface of the first end of the first sleeve 3 to the end of the second sleeve 2, and the second adhesive part fixes the end face of the second end of the first sleeve 3 to the outer surface of the reflective member.
[0031] In one embodiment of this disclosure, the adhesive portion 10 bonds the end face of the first sleeve 3 to the outer surface of the second sleeve 2. The adhesive portion 10 is concave and arc-shaped, and surrounds the outer surface of the second sleeve 2 at the junction of the first sleeve 3 and the second sleeve 2. This allows for uniform stress distribution in all directions, thereby solving the problems of zero drift during temperature changes and poor sensor consistency.
[0032] The reflecting component may include a reflecting optical fiber 8 and a third sleeve 7 disposed outside the reflecting optical fiber 8. The reflecting component may include a solid rod 9. The outer diameter of the reflecting component is approximately equal to the outer diameter of the light incident end.
[0033] The incident fiber 1 can include single-mode fiber and multimode fiber, and its diameter can be, for example, 0.155 mm. The outer diameter of the second sleeve 2 can be selected from 0.3 mm to 4.5 mm, and the outer diameter of the first sleeve can be selected from 1 mm to 10 mm. The distance between the end face 4 of the light incident end and the end face 6 of the reflecting component is the cavity length of the Fabry-Perot cavity 5, which ranges from 16 to 21 μm. When the temperature sensor is affected by temperature, it will undergo thermal expansion and contraction, causing a change in the cavity length of the Fabry-Perot cavity 5. The change in cavity length is modulated using the principle of white light interference, thereby realizing temperature measurement.
[0034] Preferably, the coefficient of thermal expansion of the first sleeve 3 is greater than that of the second sleeve 2 and the reflective component, or the coefficient of thermal expansion of the first sleeve 3 is less than that of the second sleeve 2 and the reflective component. This design results in a more sensitive temperature sensor.
[0035] Preferably, the sum of the difference between the first and second thermal expansion coefficients is greater than 2*10. -6 / ℃, the first thermal expansion coefficient difference is the difference between the thermal expansion coefficients of the first sleeve 3 and the second sleeve 2, and the second thermal expansion coefficient difference is the difference between the thermal expansion coefficients of the first sleeve 3 and the reflective component. The larger the sum of the first thermal expansion coefficient difference and the second thermal expansion coefficient difference, the higher the sensitivity of the temperature sensor.
[0036] The materials of the first sleeve 3, the second sleeve 2, and the reflective component can be ceramic, glass, or metal. Preferably, the first sleeve 3 is made of metal, and the second sleeve 2 and the reflective component are made of glass or ceramic; or the first sleeve 3 is made of ceramic, and the second sleeve 2 and the reflective component are made of glass.
[0037] The length of the first sleeve 3 can be selected from 5mm to 30mm, preferably 10mm to 20mm. The length of the first sleeve 3 is equal to the sum of the length L1 of the second sleeve 2 within the first sleeve 3, the length L2 of the reflective member within the first sleeve 3, and the cavity length of the Fabry-Perot cavity 5. The sensitivity coefficient of the temperature sensor is as follows:
[0038] Sensitivity coefficient = (AB) * L1 + (AC) * L2
[0039] Where A is the thermal expansion coefficient of the first sleeve 3, B is the thermal expansion coefficient of the second sleeve 2, C is the thermal expansion coefficient of the reflective component, L1 is the length of the second sleeve 2 inside the first sleeve 3, and L2 is the length of the reflective component inside the first sleeve 3.
[0040] In one embodiment of this disclosure, such as Figure 6 As shown, the temperature sensor also includes a protective sleeve 12 located outside the first sleeve 3 and a sealant 14 disposed at the end of the protective sleeve 12. The protective sleeve 12 is used to protect the internal components from damage by external forces. The sealant 14 is used to bond the fiber optic protective sleeve 15 and the protective sleeve 12 together, and also serves to seal the left and right end holes of the protective sleeve 12. The protective sleeve 12 can be made of ceramic, glass, metal, etc.
[0041] The temperature sensor may also include thermal grease 6 disposed between the protective sleeve 12 and the first sleeve 3. The thermal grease 6 is used to improve thermal conductivity, thereby improving the response rate of the sensor.
[0042] The temperature sensor may also include an optical fiber connector 16 and a pigtail protective sleeve 15. The optical fiber connector 16 is connected to the white light interferometry demodulation system to interface with optical signals; the pigtail protective sleeve 15 is used to protect the optical fiber; and the incident optical fiber 1 is used to transmit optical signals.
[0043] like Figure 7 The diagram shown is a structural schematic of a second embodiment of the present disclosure. The temperature sensor includes: a first sleeve 3; a light-incident end at least partially located within the first sleeve 3, the light-incident end including an incident optical fiber 1, the light-incident end being cut to form an end face 4 perpendicular to the incident optical fiber 1; a reflective member at least partially located within the first sleeve 3, the reflective member being configured to be opposite to the incident optical fiber 1, the end face 4 of the light-incident end and the end face 6 of the reflective member forming a Fabry-Perot cavity 5; and an adhesive portion 10 for fixing the first sleeve 3 to the incident optical fiber 1 and the reflective member respectively. The inner diameter of the first sleeve 3 is slightly larger than the outer diameter of the incident optical fiber 1 at the optical fiber incident end, so that the incident optical fiber 1 and the reflective member are inserted into the first sleeve 3. For example, the incident optical fiber is a multimode optical fiber with an outer diameter of 0.125 micrometers, and the inner diameter of the first sleeve is 0.127 micrometers.
[0044] For example, the first adhesive part fixes the end face of the first end of the first sleeve 3 to the outer surface of the second sleeve 2, and the second adhesive part fixes the inner surface of the second end of the first sleeve 3 to the end of the reflective member. The first end is the end of the second sleeve 2. For example, the first adhesive part fixes the inner surface of the first end of the first sleeve 3 to the end of the second sleeve 2, and the second adhesive part fixes the end face of the second end of the first sleeve 3 to the outer surface of the reflective member.
[0045] In one embodiment of this disclosure, the adhesive portion 10 bonds the end face of the first sleeve 3 to the outer surface of the second sleeve 2. The adhesive portion 10 is concave and arc-shaped, and surrounds the outer surface of the second sleeve 2 at the junction of the first sleeve 3 and the second sleeve 2. This allows for uniform stress distribution in all directions, thereby solving the problems of zero drift during temperature changes and poor sensor consistency.
[0046] In this embodiment, using the first sleeve 3 to directly wrap the incident optical fiber 1 and the reflecting component has the following advantages: Firstly, compared to the first sleeve in the above embodiment where thermal expansion and contraction only occurs in part of the Fabry-Perot cavity 5, in this embodiment, due to the smaller friction between the first sleeve 3 and the incident optical fiber 1 and the reflecting component, the first sleeve 3 undergoes thermal expansion and contraction throughout its entire length, increasing the range of thermal expansion and contraction and thus improving the accuracy of the temperature sensor. Secondly, it improves the temperature sensitivity of the temperature sensor.
[0047] Furthermore, the technical features disclosed above are not limited to the combinations of the disclosed features with other features. Those skilled in the art can also make other combinations of the technical features according to the purpose of the disclosure in order to achieve the purpose of this disclosure.
Claims
1. A temperature sensor, characterized by, The application relates to a Fabry-Perot cavity, comprising: a first sleeve; a light incident end at least partially located in the first sleeve; a reflecting member at least partially located in the first sleeve, the reflecting member being arranged opposite to the light incident end, and an end surface of the light incident end and an end surface of the reflecting member forming a Fabry-Perot cavity; the light incident end and the reflecting member are fixedly connected with the first sleeve.
2. The temperature sensor of claim 1, wherein, The light incident end is an incident optical fiber, and the incident optical fiber is inserted into the first sleeve.
3. The temperature sensor of claim 2, wherein, An end surface of an end portion of the first sleeve is bonded with an outer surface of the incident optical fiber.
4. The temperature sensor of claim 1, wherein, The reflecting member is a reflecting optical fiber or a reflecting rod.
5. The temperature sensor of claim 1, wherein, The light incident end comprises an incident optical fiber and a second sleeve sleeved outside the incident optical fiber, and the second sleeve is inserted into the first sleeve.
6. The temperature sensor of claim 5, wherein, An end portion of the second sleeve is recessed inward relative to an end portion of the first sleeve, and an inner surface of the end portion of the first sleeve is bonded with an end surface of the second sleeve.
7. The temperature sensor of claim 1, wherein, the sum of the first coefficient of thermal expansion difference and the second coefficient of thermal expansion difference is greater than 2*10 -6 / °C, the first coefficient of thermal expansion difference being a difference between a coefficient of thermal expansion of the first sleeve and the light entry end, the second coefficient of thermal expansion difference being a difference between a coefficient of thermal expansion of the first sleeve and the reflective member.
8. The temperature sensor of claim 7, wherein, Materials of the first sleeve and the reflecting member are selected from one of the following: metal, ceramic or glass.
9. The temperature sensor of claim 1, wherein, A cavity length of the Fabry-Perot cavity is 10-30 microns.
10. The temperature sensor of claim 1, wherein, The application further relates to a Fabry-Perot cavity, comprising: a protective sleeve arranged outside the first sleeve and a sealing glue arranged at an end portion of the protective sleeve.