Optical path integrated packaging module and current measuring device

Abstract

According to the optical path integrated packaging module and the current measuring device provided by the invention, the polarization unit, the non-polarization beam splitting unit and the polarization beam splitting detection unit are integrated and packaged in the shell of which the surface is provided with the plurality of optical fiber interfaces, and a spatial optical path transmission scheme is designed; reflected light containing Faraday rotation angle information is returned to the polarization beam splitting detection unit along an original path, so that the influence of environmental interference and crosstalk of optical devices on a light polarization state can be effectively avoided, the sensitivity of traditional optical fiber connection to environmental vibration and polarization state drift is overcome, all the advantages of the traditional optical fiber connection are reserved, and the reliability of the optical fiber connection is improved. And meanwhile, a fragile spatial light path is converted into a stable integrated structure, so that the plug and play of the device is realized, the stability and reliability of light path transmission are improved, and finally, the module has high performance and high reliability, and meets the precision requirements on polarization state modulation and detection in scenes such as to-be-detected current detection and the like.

Description

Technical Field

[0001] This invention relates to the field of fiber optic sensing technology, and in particular to an optical path integrated packaging module and a current measuring device. Background Technology

[0002] Current measurement is of great significance in fields such as power systems. Traditional current measurement methods generally suffer from technical bottlenecks such as severe electromagnetic interference, poor insulation, and small dynamic range. In contrast, fiber optic current sensing technology, with its outstanding advantages such as resistance to electromagnetic interference and excellent insulation performance, has become a research hotspot in this field. The technical principles of fiber optic current sensing are diverse, including mechanisms such as the Faraday effect, magnetostriction effect, and magnetohydrodynamic materials. Among them, the scheme based on the Faraday effect has become the core research direction due to its intuitive response to current changes and convenient detection.

[0003] However, existing optical current sensing systems mostly employ all-fiber optic connections, which presents key problems such as susceptibility of polarization states to environmental disturbances and insufficient long-term operational stability. Specifically, while lasers, commonly used in existing systems, can improve the signal-to-noise ratio, their relatively long coherence length can easily induce interference effects in the fiber optic loop, interfering with the stable transmission of polarized light. Optical circulators have complex structures involving multiple polarization state conversion mechanisms, making it difficult for polarized light to maintain a stable state after passing through them. Furthermore, the optical components are assembled via fiber optic connections, and during long-term measurements, the optical path of the non-sensing parts is susceptible to environmental factors such as temperature fluctuations and mechanical vibrations, leading to polarization state drift and ultimately reducing the system's measurement stability.

[0004] Therefore, there is an urgent need for an integrated optical path packaging module and a current measurement device to solve the above-mentioned technical problems. Summary of the Invention

[0005] The purpose of this invention is to provide an optical path integrated packaging module and a current measurement device to solve the technical problem of polarization instability caused by external environment in existing all-fiber structures.

[0006] To solve the above-mentioned technical problems, the present invention first provides an optical path integrated packaging module, including a housing with multiple optical fiber interfaces on its surface, and a polarization unit, a non-polarization beam splitting unit and a polarization beam splitting detection unit disposed inside the housing; The polarization unit converts incident light input through one fiber optic interface into transmitted light with a polarization state. The non-polarization beam splitting unit splits the transmitted light into sensing light and reference light according to a preset ratio, and both the sensing light and the reference light maintain the polarization state of the transmitted light. After the sensing light is output to an external device under test through another fiber optic interface, the external device under test modulates and changes the polarization state to generate reflected light containing Faraday rotation angle information. The reflected light returns along the original path to the polarization beam splitting detection unit. The polarization beam splitting detection unit decomposes the reflected light into first linearly polarized light and second linearly polarized light with orthogonal vibration directions.

[0007] Preferably, the housing contains multiple collimating lenses, each corresponding to a fiber optic interface and aligned with the central axis of the end face of the corresponding fiber optic interface.

[0008] Preferably, the polarizing unit includes a polarizer oriented at 45°, which is used to convert the collimated incident light into transmitted light, and the transmitted light is 45° linearly polarized light.

[0009] Preferably, the non-polarized beam splitter unit is optically connected to the polarization unit, and the non-polarized beam splitter unit is a non-polarized beam splitter cubic crystal; the polarized beam splitter detection unit is a polarized beam splitter cube, used to decompose the collimated reflected light into a first linearly polarized light and a second linearly polarized light; the first linearly polarized light is P-polarized light, and the second linearly polarized light is S-polarized light.

[0010] Accordingly, the present invention also provides a current detection device, including an optical path integrated packaging module as described in any of the above claims, and a light source module, an external device under test, and a photoelectric detection and analysis module that are connected one-to-one with multiple optical fiber interfaces, wherein the external device under test is a reflective polarization modulation module. The light source module is used to input incident light; the reflective polarization modulation module is used to modulate the polarization state of the sensing light with the magnetic field generated by the current to be measured, obtain the reflected light and return it to the polarization beam splitting detection unit; the photoelectric detection and analysis module is used to detect the optical power of the first linearly polarized light and the second linearly polarized light respectively and convert them into electrical signals, and analyze the correlation between the electrical signals and the Faraday rotation angle, and finally obtain the measured value of the current to be measured.

[0011] Preferably, the light source module includes a superluminescent diode and an isolator. The input end of the isolator is optically connected to the superluminescent diode, and the output end of the isolator is optically connected to the first fiber optic interface of the housing through a first single-mode fiber.

[0012] Preferably, the current measuring device further includes a polarization analyzer, which is optically connected to the second fiber optic interface of the housing via a first circularly polarized optical fiber, and is used to detect the polarization state of the collimated reference light in real time.

[0013] Preferably, the reflective polarization modulation module includes a sensing coil and a Faraday rotator. The sensing coil is optically connected to the third fiber optic interface of the housing through a second circularly polarized optical fiber to sense the magnetic field of the current to be measured in order to modulate the polarization state of the collimated sensing light. The Faraday rotator is used to reflect the modulated sensing light to form reflected light, which then returns to the third fiber optic interface along the original path.

[0014] Preferably, the photoelectric detection and analysis module includes a first photodetector and a second photodetector. The first photodetector is optically connected to the fourth fiber optic interface of the housing through a second single-mode fiber and is used to detect the optical power P1 of the first polarized light. The second photodetector is optically connected to the fifth fiber optic interface of the housing through a third single-mode fiber and is used to detect the optical power P2 of the second polarized light.

[0015] Preferably, the photoelectric detection and analysis module further includes a signal processing unit electrically connected to the first photodetector and the second photodetector respectively. The signal processing unit is used to calculate the differential signal S=(P1-P2) / (P1+P2) based on the optical power P1 and the optical power P2, and determine the measured value of the current to be measured by combining the quantitative relationship between the Faraday rotation angle and the current to be measured.

[0016] The beneficial effects of this invention are as follows: Unlike existing technologies, this invention provides an integrated optical path packaging module and a current measurement device. The integrated optical path packaging module integrates a polarization unit, a non-polarization beam splitter unit, and a polarization beam splitter detection unit into a housing with multiple fiber optic interfaces on its surface. A spatial optical path transmission scheme is designed so that reflected light containing Faraday rotation angle information returns along the original path to the polarization beam splitter detection unit. This effectively avoids the influence of environmental interference and crosstalk from optical devices on the optical polarization state, overcomes the sensitivity of traditional fiber optic connections to environmental vibration and polarization state drift, thus retaining all the advantages of traditional fiber optic connections. Simultaneously, it transforms the fragile spatial optical path into a stable integrated structure, thereby achieving plug-and-play functionality, improving the stability and reliability of optical path transmission, and ultimately enabling the module to possess both high performance and high reliability, meeting the accuracy requirements for polarization state modulation and detection in scenarios such as current measurement. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall architecture of the optical path integrated packaging module provided in Example 1; Figure 2 This is a schematic diagram of the current measuring device provided in Example 1; In the attached diagram: 100 – housing; 11 – polarization unit; 12 – non-polarization beam splitting unit; 13 – polarization beam splitting detection unit; 14 – collimating lens; 21 – superluminescent diode; 22 – isolator; 31 – sensing coil; 32 – Faraday rotator; 41 – first photodetector; 42 – second photodetector. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0019] This invention addresses the shortcomings of existing technologies by proposing an optical path integrated packaging module and a current measurement device. It aims to solve the drawback of traditional optical current sensing systems requiring the connection of several discrete components via optical fibers, while also overcoming the problems of light polarization state being susceptible to environmental interference and crosstalk between optical components.

[0020] This invention designs a spatial optical path transmission scheme that integrates multiple independent spatial optical crystals into a single device. This eliminates the core defects caused by fiber optic connections, such as polarization drift and sensitivity to environmental vibrations, while retaining the inherent advantages of the original technology. Simultaneously, it effectively reduces the device size. By transforming the fragile spatial optical path into a stable, plug-and-play integrated structure, the device achieves both high performance and high reliability. This integrated device effectively improves the stability of system measurements and has significant application prospects in practical fiber optic current sensing systems.

[0021] The technical solution of the present invention will now be further described with reference to specific embodiments.

[0022] Example 1: Please see Figure 1 , Figure 1 The above is a schematic diagram of the overall architecture of the optical path integrated packaging module provided in Embodiment 1; wherein, the optical path integrated packaging module includes a housing 100 with multiple optical fiber interfaces on its surface, and a polarization unit 11, a non-polarization beam splitting unit 12 and a polarization beam splitting detection unit 13 are provided inside the housing 100. The polarization unit 11 converts incident light input through an optical fiber interface into transmitted light with a polarization state; the non-polarization beam splitting unit 12 splits the transmitted light into sensing light and reference light according to a preset ratio, and both the sensing light and the reference light maintain the polarization state of the transmitted light; after the sensing light is output to an external device under test through another optical fiber interface, the external device under test modulates and changes the polarization state to generate reflected light containing Faraday rotation angle information, and the reflected light returns along the original path to the polarization beam splitting detection unit 13; the polarization beam splitting detection unit 13 decomposes the reflected light into first linearly polarized light and second linearly polarized light with orthogonal vibration directions.

[0023] In Embodiment 1, the housing 100 contains a plurality of collimating lenses 14, each corresponding to a fiber optic interface and aligned with the central axis of the end face of the corresponding fiber optic interface. This design precisely couples the optical signals between the fiber optic interface and the optical path within the housing 100, collimating the divergent light transmitted through the fiber optic cable into parallel light (or conversely focusing it), reducing optical signal transmission loss and polarization state shift. This ensures the coaxiality and stability of the optical path in subsequent optical processes such as polarization modulation and beam splitting detection, while also enhancing the compactness of the integrated optical path packaging structure.

[0024] In Embodiment 1, the polarization unit 11 includes a polarizer oriented at 45°, which is used to convert the collimated incident light into transmitted light, and the transmitted light is 45° linearly polarized light.

[0025] In Embodiment 1, the non-polarized beam splitting unit 12 is optically connected to the polarization unit 11, and the non-polarized beam splitting unit 12 is a non-polarized beam splitting cubic crystal; the polarized beam splitting detection unit 13 is a polarized beam splitting cube, used to decompose the collimated reflected light into a first linearly polarized light and a second linearly polarized light; the first linearly polarized light is P-polarized light, and the second linearly polarized light is S-polarized light.

[0026] Specifically, the aforementioned optical path integrated packaging module integrates the polarization unit 11, the non-polarization beam splitting unit 12, and the polarization beam splitting detection unit 13 into a housing 100 with multiple fiber optic interfaces on its surface. A spatial optical path transmission scheme is designed so that the reflected light containing Faraday rotation angle information returns along the original path to the polarization beam splitting detection unit 13. This effectively avoids the influence of environmental interference and crosstalk from optical devices on the optical polarization state, overcomes the sensitivity of traditional fiber optic connections to environmental vibration and polarization state drift, thus retaining all the advantages of traditional fiber optic connections. It transforms the fragile spatial optical path into a stable integrated structure, thereby achieving plug-and-play functionality, improving the stability and reliability of optical path transmission, and ultimately enabling the module to possess both high performance and high reliability, meeting the accuracy requirements for polarization state modulation and detection in scenarios such as current detection.

[0027] Please see Figure 2 , Figure 2 The diagram below shows the structure of the current measuring device provided in Example 1. The current measuring device includes an optical path integrated packaging module, and a light source module, a reflective polarization modulation module, and a photoelectric detection and analysis module that are connected one-to-one with the optical fiber interfaces of the optical path integrated packaging module. The optical path integrated packaging module includes a housing 100 with multiple optical fiber interfaces. The housing 100 contains a polarization unit 11, a non-polarization beam splitting unit 12, and a polarization beam splitting detection unit 13. The light source module is used to input incident light; the reflective polarization modulation module is used to modulate the polarization state of the sensing light with the magnetic field generated by the current to be measured, obtain the reflected light and return it to the polarization beam splitting detection unit; the photoelectric detection and analysis module is used to detect the optical power of the first linearly polarized light and the second linearly polarized light respectively and convert them into electrical signals, and analyze the correlation between the electrical signals and the Faraday rotation angle, and finally obtain the measured value of the current to be measured.

[0028] Specifically, in Embodiment 1, the polarization unit 11, the non-polarization beam splitting unit 12, and the polarization beam splitting detection unit 13 are integrated into a housing 100 with multiple fiber optic interfaces to form an integrated optical path packaging module. This allows the light source module, the reflective polarization modulation module, the photoelectric detection and analysis module, and the fiber optic interfaces to be connected one-to-one. With the coordinated operation of polarization, polarization modulation, orthogonal beam splitting, optical power detection, and electrical signal correlation analysis, the integration of the optical path and the directionality of transmission are achieved. This effectively avoids the polarization state drift and environmental interference problems caused by discrete devices connected to traditional optical fibers, significantly improves the stability and accuracy of system measurements, simplifies the device structure, reduces the device size, and combines practicality and reliability.

[0029] In Embodiment 1, the light source module includes a superluminescent diode 21 and an isolator 22. The input end of the isolator 22 is optically connected to the superluminescent diode 21, and the output end of the isolator 22 is optically connected to the first fiber optic interface of the housing 100 through a first single-mode fiber (using FC / APC type connection). The superluminescent diode 21 can reduce optical path interference effects due to its short coherence length characteristic. The isolator 22 can effectively block reflected light backlash in the optical path to protect the stable operation of the light source and avoid polarization state interference. The single-mode fiber ensures single-mode transmission and low-loss coupling of the incident light.

[0030] In Example 1, the optical path integrated packaging module 20 is a multi-channel integrated optical module, which integrates seven core functional units to form a complete optical signal processing chain. Each unit works collaboratively according to the signal flow direction, and its specific functions are as follows: Input Channel (CH1): Serving as the optical signal input port of the device, it adopts a standard single-mode fiber optic interface such as FC / APC and is responsible for receiving incident light emitted by broadband light sources such as the superluminescent diode 21. After the optical signal is output from the light source, it passes sequentially through isolator 22 and single-mode fiber, and is coupled with collimating lens 14 to form parallel spatial light that enters the device. Isolator 22 can prevent subsequent reflected light from returning to the light source, ensuring the stability of the light source operation.

[0031] Polarizing unit 11: Collimating lens 14 converts the incident light into a highly parallel spatial beam, which is then converted into 45° linearly polarized light by a 45° oriented polarizer (ILP); the 45° polarization design can improve the system sensitivity in the subsequent signal demodulation process.

[0032] Non-polarized beam splitter unit 12: Employs a non-polarized beam splitter cubic crystal (NPBS), whose core characteristic is to maintain the incident light polarization state unchanged and split 45° linearly polarized light (the incident light after polarization by the polarizer) into two beams according to a preset ratio: Sensing light: The polarization state remains unchanged, and it enters the sensing light path channel; Reference light: Its polarization state remains unchanged, and it enters the reference light path channel.

[0033] Reference optical path channel (CH2): This is a unidirectional optical path channel that receives the reference light output from the non-polarization beam splitter 12. It can provide a reference signal for the system and adapt to functions such as temperature compensation and polarization state change reference. A polarization analyzer can be connected to the end of the channel as needed to realize real-time polarization state detection.

[0034] Sensing optical path channel (CH3): As a bridge connecting the device and the sensing coil 31, the sensing beam output by the non-polarization beam splitter 12 is coupled into the polarization-maintaining fiber (maintaining the polarization state of the light) through the collimating lens 14 and transmitted to the external sensing coil 31; the magnetic field generated by the current to be measured will cause the polarization plane of the linearly polarized light to deflect, and the reflected light carrying the Faraday effect information returns to the device through the collimating lens 14 of this channel.

[0035] Polarization beam splitting detection unit 13: This is the core unit for signal demodulation, composed of a polarization beam splitting cube (PBS). Light returning from the sensing optical path is reflected by the non-polarization beam splitting crystal and then incident on this unit, where it is decomposed into two orthogonally linearly polarized beams: P-polarized light and S-polarized light. Due to the Faraday effect causing the polarization plane to rotate, the energy components of the two beams change with the measured current, and this change is directly proportional to the current.

[0036] Output channels (CH4 and CH5): These include two independent first and second output channels, which receive P-polarized light and S-polarized light output from the polarization beam splitting detection unit 13, respectively. Each channel is equipped with a collimating lens 14 to efficiently couple spatial light to a single-mode fiber and transmit it to the first photodetector 41 (PD1) and the second photodetector 42 (PD2). By detecting the optical power P1 and optical power P2 received by PD1 and PD2 respectively, the Faraday rotation angle caused by the current can be accurately demodulated, ultimately achieving precise measurement of the current to be measured.

[0037] In Example 1, all optical components of the optical path integrated packaging module 20 are first aligned and adjusted by optical path debugging, then integrated onto the same substrate, and subsequently packaged into a housing to form an integrated module. Five standard FC / APC fiber optic interfaces are distributed at both ends and sides of the housing, and each interface is connected to the internal collimating lens 14, which facilitates quick connection of external modules by users. At the same time, the internal optical path of the module adopts a coplanar design to ensure that the main light rays propagate in the same plane, effectively avoiding optical path offset problems and ensuring optical path alignment accuracy. This not only enhances the compactness and stability of the module structure, but also improves the practicality and external compatibility of the device through standardized interfaces, laying the foundation for the efficient assembly and stable operation of the entire current measurement device.

[0038] In Embodiment 1, the reflective polarization modulation module 30 includes a sensing coil 31 and a Faraday rotator 32. The sensing coil 31 is optically connected to the third fiber optic interface of the housing 100 through a second circularly polarized fiber to sense the magnetic field of the current to be measured in order to modulate the polarization state of the collimated sensing light. The Faraday rotator 32 is used to reflect the modulated sensing light to form reflected light and return it to the third fiber optic interface along the original path. The second circularly polarized fiber can maintain the stability of the polarization state of the sensing light throughout the process. The sensing coil 31 can efficiently sense the magnetic field of the current to be measured and accurately modulate the polarization state of the sensing light to load Faraday effect information. The Faraday rotator 32 realizes the efficient reflection and return of the modulated light along the original path.

[0039] In Embodiment 1, the photoelectric detection and analysis module 40 further includes a signal processing unit electrically connected to the first photodetector 41 and the second photodetector 42, respectively. The signal processing unit is used to calculate the differential signal S=(P1-P2) / (P1+P2) based on the optical power P1 and optical power P2, and determine the measured value of the current to be measured by combining the quantitative relationship between the Faraday rotation angle and the current to be measured. This design can effectively suppress common-mode noise such as light source power fluctuations and ambient light interference, and offset the influence of polarization state drift caused by non-current factors. At the same time, it transforms the correlation between optical power difference and current into a directly calculable quantitative relationship, realizes accurate demodulation of the Faraday rotation angle, and significantly improves the anti-interference capability, measurement accuracy and data reliability of current measurement.

[0040] Please refer to the following: Figure 2 The specific working process of the current measuring device based on spatial optical path encapsulation provided in Example 1 for measuring the current to be measured is as follows: First, using a superluminescent diode 21 as the light source, the incident light emitted by it passes through an isolator 22 and then enters the input channel (CH1) of the optical path integrated packaging module 20 through the first optical fiber interface. Subsequently, it is coupled into parallel spatial light by a single-mode fiber and a collimating lens 14. This parallel beam passes through a polarizer oriented at 45° and forms 45° linearly polarized light. This linearly polarized light is then incident on a non-polarizing beam splitter crystal and splits into two paths: one is sensing light, which is coupled through the collimating lens 14 into the polarization-maintaining fiber of the sensing optical path channel (CH3); the other is reference light, which is coupled through the collimating lens 14 into the single-mode fiber of the reference optical path channel (CH2) and then enters the reference optical path.

[0041] Secondly, after the polarized light emitted from the sensing optical path channel is transmitted to the sensing coil 31, a magnetic field is generated due to the current I being measured. According to the Faraday effect, the polarization plane of the light will rotate, and the Faraday rotation angle satisfies the formula θ = V. ∫H The polarized light carrying information about the Faraday effect continues to be transmitted to the Faraday rotator 32, and after reflection, it returns to the optical path integrated packaging module 20 through the sensing optical path channel. The polarized light is dl (where V is the Wilder constant, H is the magnetic field strength, and dl is the integral path element), and this Faraday rotation angle θ is directly proportional to the current I.

[0042] Next, the returned polarized light is incident on the non-polarized beam splitter crystal again: the transmitted light is blocked by isolator 22 and cannot be transmitted in reverse; the reflected light enters the polarized beam splitter crystal, and the beam whose polarization plane has been rotated is decomposed into two beams of light with different polarization states (P-polarized light and S-polarized light). The two beams are coupled into the single-mode optical fibers of the first output channel (CH4) and the second output channel (CH5) through collimating lens 14, respectively.

[0043] Finally, by detecting the optical power received by the first photodetector 41 (PD1) and the second photodetector 42 (PD2) connected to CH4 and CH5, let the optical power detected by PD1 be P1 and the optical power detected by PD2 be P2. The signal processing unit calculates the differential signal: S=(P1-P2) / (P1+P2).

[0044] Theoretically, S∝sin(2θ), that is, S=K×sin(2θ); where the system proportionality coefficient K is obtained through standard current calibration, and after calibration, it is fixedly stored in the signal processing unit for quantitative calculation of current measurement, so as to compensate for the error caused by the non-ideal characteristics of optical components and improve the measurement accuracy.

[0045] When θ is small (θ < 10°), it can be approximated as sin(2θ) ≈ 2θ, according to the Faraday effect formula θ = V ∫H dl, combined with Ampere's circuital law (when the number of turns of sensing coil 31 is N, ∫H dl=N×I), from which we can obtain θ=V N I; By combining S≈K×2θ and S=(P1-P2) / (P1+P2), we can know that: (P1-P2) / (P1+P2)≈2K×(V N I); Since K, V and N are all known quantities, the current to be measured I can be obtained from P1 and P2.

[0046] Therefore, the differential signal S is directly proportional to the current I. This differential detection method can effectively eliminate common-mode noise caused by fluctuations in light source power, significantly improve the accuracy and stability of the measurement, and thus achieve accurate current measurement.

[0047] Unlike existing technologies, the core advantage of the current measurement device provided by this invention lies in its precise solution to the core pain points of existing optical current sensing technologies: Addressing the shortcomings of existing solutions, such as the susceptibility of optical polarization state to environmental interference (e.g., vibration), crosstalk of optical devices, and the sensitivity to polarization state drift in traditional fiber optic connections, this invention innovatively designs a spatial optical path transmission scheme. This scheme integrates multiple independent spatial optical crystals into a single integrated device—effectively overcoming the key problems of sensitivity to environmental vibration and easy polarization state drift in traditional fiber optic connections, while fully retaining the inherent advantages of the original technology (e.g., low transmission loss). Simultaneously, through integrated packaging, the originally fragile discrete spatial optical path is transformed into a structurally stable, plug-and-play integrated device. This not only solves the vulnerability problem of discrete optical paths but also improves the ease of installation and structural compactness of the device. Ultimately, the device simultaneously possesses high measurement performance (precise polarization modulation and detection) and long-term operational reliability, significantly outperforming existing sensing solutions that combine discrete optical devices or use all-fiber connections.

[0048] It should be noted that all the above embodiments belong to the same inventive concept, and the descriptions of each embodiment have different focuses. Where the description in a particular embodiment is not detailed, please refer to the description in other embodiments.

[0049] The above embodiments merely illustrate implementation methods of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. An optical path integrated packaging module, characterized in that, The device includes a housing with multiple fiber optic interfaces on its surface, and the housing contains a polarization unit, a non-polarization beam splitting unit, and a polarization beam splitting detection unit. The polarization unit converts incident light input via one of the optical fiber interfaces into transmitted light with a polarization state. The non-polarization beam splitting unit splits the transmitted light into sensing light and reference light according to a preset ratio, and both the sensing light and the reference light maintain the polarization state of the transmitted light. The sensing light is output to an external device under test (DUT) via another optical fiber interface, and its polarization state is modulated by the external DUT to generate reflected light containing Faraday rotation angle information. The reflected light returns along the original path to the polarization beam splitting detection unit. The polarization beam splitting detection unit decomposes the reflected light into first linearly polarized light and second linearly polarized light with orthogonal vibration directions.

2. The optical path integrated packaging module according to claim 1, characterized in that, The housing contains a plurality of collimating lenses, each of which corresponds to one of the optical fiber interfaces and is aligned with the central axis of the end face of the corresponding optical fiber interface.

3. The optical path integrated packaging module according to claim 2, characterized in that, The polarizing unit includes a polarizer oriented at 45°, which is used to convert the collimated incident light into transmitted light, the transmitted light being 45° linearly polarized light.

4. The optical path integrated packaging module according to claim 2, characterized in that, The non-polarized beam splitter unit is optically connected to the polarizing unit, and the non-polarized beam splitter unit is a non-polarized beam splitter cubic crystal; the polarized beam splitter detection unit is a polarized beam splitter cube, used to decompose the collimated reflected light into the first linearly polarized light and the second linearly polarized light; the first linearly polarized light is P-polarized light, and the second linearly polarized light is S-polarized light.

5. A current detection device, characterized in that, It includes the optical path integrated packaging module as described in any one of claims 1 to 4, as well as the light source module, the external device under test and the photoelectric detection and analysis module, which are connected one-to-one with the plurality of optical fiber interfaces, wherein the external device under test is a reflective polarization modulation module; The light source module is used to input the incident light; the reflective polarization modulation module is used to modulate the polarization state of the sensing light with the magnetic field generated by the current to be measured, to obtain the reflected light and return it to the polarization beam splitting detection unit; the photoelectric detection and analysis module is used to detect the optical power of the first linearly polarized light and the second linearly polarized light respectively and convert them into electrical signals, and analyze the correlation between the electrical signals and the Faraday rotation angle, and finally obtain the measured value of the current to be measured.

6. The current detection device according to claim 5, characterized in that, The light source module includes a superluminescent diode and an isolator. The input end of the isolator is optically connected to the superluminescent diode, and the output end of the isolator is optically connected to the first fiber optic interface of the housing through a first single-mode fiber.

7. The current detection device according to claim 5, characterized in that, The current measuring device also includes a polarization analyzer, which is optically connected to the second fiber optic interface of the housing via a first circularly polarized optical fiber, and is used to detect the polarization state of the collimated reference light in real time.

8. The current detection device according to claim 5, characterized in that, The reflective polarization modulation module includes a sensing coil and a Faraday rotator. The sensing coil is optically connected to the third fiber optic interface of the housing through a second circularly polarized optical fiber. It is used to sense the magnetic field of the current to be measured to modulate the polarization state of the collimated sensing light. The Faraday rotator is used to reflect the modulated sensing light to form the reflected light, which returns to the third fiber optic interface along the original path.

9. The current detection device according to claim 5, characterized in that, The photoelectric detection and analysis module includes a first photodetector and a second photodetector. The first photodetector is optically connected to the fourth fiber optic interface of the housing through a second single-mode fiber and is used to detect the optical power P1 of the first polarized light. The second photodetector is optically connected to the fifth fiber optic interface of the housing through a third single-mode fiber and is used to detect the optical power P2 of the second polarized light.

10. The current detection device according to claim 9, characterized in that, The photoelectric detection and analysis module further includes a signal processing unit electrically connected to the first photodetector and the second photodetector respectively. The signal processing unit is used to calculate the differential signal S=(P1-P2) / (P1+P2) based on the optical power P1 and the optical power P2, and determine the measured value of the current to be measured by combining the quantitative relationship between the Faraday rotation angle and the current to be measured.

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