Optical fiber device and measuring system

Abstract

The embodiment of the invention provides an optical fiber device and a measurement system. The optical fiber device comprises a packaging shell which is provided with a first side wall and a second side wall; the first optical fiber port is arranged on the first side wall, and the first optical fiber port is a light incidence port; the second optical fiber port is arranged on the second side wall, and the second optical fiber port is a light emitting port; the half-wave plate is arranged in the packaging shell and is close to the first optical fiber port; the polarization splitting prism is arranged in the packaging shell, the polarization splitting prism is arranged between the half-wave plate and the second optical fiber port, and the half-wave plate and the polarization splitting prism are sequentially arranged in the incident direction of light; the first optical fiber port is used for inputting first signal light into the packaging shell; the half-wave plate is used for changing the polarization state of the first signal light into second signal light, the polarization splitting prism is used for transmitting the second signal light into third signal light along the first optical path, and the second optical fiber port is used for outputting the third signal light. According to the embodiment of the invention, the calibration efficiency and measurement precision of quantum precision measurement can be improved.

Description

Technical Field

[0001] The present invention relates to the field of optical fiber technology, and in particular to an optical fiber device and a measuring system. Background Art

[0002] In the field of quantum precision measurement, high-precision quantum measurement equipment such as atomic clocks and cold atom gravimeters have high requirements for the polarization, power and direction of the laser. At present, the autocollimator solution or the addition of a pinhole aperture is usually used to adjust the direction of the optical path with high precision. Adjustment using the autocollimator solution will make the system adjustment complicated, which is not suitable for field test environments and seriously affects the measurement efficiency. The pinhole aperture method has poor measurement accuracy and cannot meet the high-precision measurement requirements. Summary of the invention

[0003] Therefore, in order to overcome at least some of the defects and shortcomings in the prior art, an embodiment of the present invention provides an optical fiber device and a measurement system.

[0004] Specifically, on the one hand, an embodiment of the present invention provides an optical fiber device, comprising: a packaging shell having a first side wall and a second side wall opposite to each other; a first optical fiber port, arranged on the first side wall of the packaging shell, the first optical fiber port being a light incident port; a second optical fiber port, arranged on the second side wall of the packaging shell, the second optical fiber port being a light exit port; a half-wave plate, arranged in the packaging shell and close to the first optical fiber port; a polarization beam splitter prism, arranged in the packaging shell, the polarization beam splitter prism being arranged between the half-wave plate and the second optical fiber port, and the half-wave plate and the polarization beam splitter prism being arranged in sequence along the incident direction of light; wherein the first optical fiber port is used to input a first signal light into the packaging shell; the half-wave plate is used to change the polarization state of the first signal light into a second signal light, the polarization beam splitter prism is used to transmit the second signal light along the first optical path into a third signal light, and the second optical fiber port is used to output the third signal light.

[0005] In a specific embodiment of the present invention, the optical fiber device also includes: a first collimator, arranged on the first optical fiber port, the first collimator is used to convert the first signal light of the first optical fiber port into a collimated light beam and input it into the packaging shell; a second collimator, arranged on the second optical fiber port, the second collimator is used to couple the third signal light to the second optical fiber port for output.

[0006] In a specific embodiment of the present invention, the packaging shell also has a third side wall located between the first side wall and the second side wall; the optical fiber device also includes: a third optical fiber port, arranged on the third side wall of the packaging shell; the second optical fiber port is also used to receive a fourth signal light after the third signal light is reflected by a measuring device, the polarization beam splitter prism is also used to reflect the fourth signal light into a fifth signal light along a second optical path, the third optical fiber port is used to output the fifth signal light, and the second optical path is perpendicular to the first optical path.

[0007] In a specific embodiment of the present invention, the packaging shell also has a fourth side wall arranged opposite to the third side wall; the optical fiber device also includes: a fourth optical fiber port, arranged on the fourth side wall of the packaging shell; the polarization splitter prism is also used to reflect the second signal light into a sixth signal light along the third optical path, and the fourth optical fiber port is used to output the sixth signal light.

[0008] In a specific embodiment of the present invention, the half-wave plate is movably connected to the packaging shell, and the half-wave plate is used to adjust the power ratio of the third signal light and the sixth signal light.

[0009] In a specific embodiment of the present invention, the optical fiber device also includes: a third collimator, arranged on the third optical fiber port, the third collimator is used to couple the fifth signal light to the third optical fiber port for output; and a fourth collimator, arranged on the fourth optical fiber port, the fourth collimator is used to couple the sixth signal light to the fourth optical fiber port for output.

[0010] On the other hand, an embodiment of the present invention further provides a measurement system, comprising: the optical fiber device as described above; and a measurement device, wherein the measurement device is connected to the second optical fiber port of the optical fiber device via an optical fiber.

[0011] In a specific embodiment of the present invention, a fifth optical fiber port is provided on the measuring device, and the fifth optical fiber port and the second optical fiber port are connected by an optical fiber. A quarter wave plate and a reflector are sequentially arranged in the measuring device along the incident direction of the light; the fifth optical fiber port is used to input the third signal light into the measuring device, and the third signal light passes through the quarter wave plate and the reflector in sequence, and after being reflected by the reflector and then changing the polarization state through the quarter wave plate, it becomes the seventh signal light, and the quarter wave plate and the reflector are used to make the optical paths of the third signal light and the seventh signal light coincide, and the fifth optical fiber port is also used to output the seventh signal light to the second optical fiber port.

[0012] In a specific embodiment of the present invention, the quarter wave plate and the reflector are both movably disposed in the measuring device, the quarter wave plate is used to adjust the polarization directions of the third signal light and the seventh signal light, and the reflector is used to adjust the degree of optical path overlap between the third signal light and the seventh signal light.

[0013] In a specific embodiment of the present invention, the measurement system further includes: a fifth collimator, disposed at the fifth optical fiber port, the fifth collimator being used to convert the third signal light of the fifth optical fiber port into a collimated light beam and input it into the measurement device, and to couple the seventh signal light to the fifth optical fiber port for output.

[0014] As can be seen from the above, the optical fiber device provided in the embodiment of the present invention is provided with a first optical fiber port and a second optical fiber port on the packaging shell, and a half-wave plate and a polarization splitter prism are sequentially arranged in the packaging shell along the incident direction of the light. The action laser, for example, the first signal light is input into the packaging shell through the first optical fiber port, and the first signal light passes through the half-wave plate and then is transmitted through the polarization splitter prism as the third signal light output, so that the third signal light output by the optical fiber device has the characteristics of a high polarization extinction ratio, thereby improving the polarization characteristics of the light, and further improving the calibration efficiency and measurement accuracy of quantum precision measurement.

[0015] The optical fiber device provided in the embodiment of the present invention has the following functions:

[0016] (1) Adjustment of the optical path direction of the measurement system: The third signal light outputted by the optical fiber device through the second optical fiber port passes through the measurement system and then outputs the seventh signal light which returns from the second optical fiber port. When the fifth signal light outputted from the third optical fiber port is the strongest, the optical path directions of the third signal light and the seventh signal light have a high overlap, that is, the optical path direction adjustment is achieved;

[0017] (2) Improving output polarization: The polarization characteristics of the first signal light input from the first optical fiber port can be improved by the polarization beam splitter, and the polarization characteristics of the third signal light output from the optical fiber device can be improved;

[0018] (3) Power distribution adjustment: By rotating the half-wave plate in the optical fiber device, the output power distribution adjustment of the third signal light and the sixth signal light can be achieved;

[0019] (4) Power monitoring: The fourth optical fiber port can be used as a system power monitoring port, and system power monitoring is achieved by monitoring the optical power of the sixth signal light output by the fourth optical fiber port. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0021] Figure 1 A schematic structural diagram of an optical fiber device provided in an embodiment of the present invention.

[0022] Figure 2 A schematic diagram of the structure of a measurement system provided by an embodiment of the present invention.

[0023] Figure 3 Another schematic diagram of the structure of the optical fiber device provided in an embodiment of the present invention.

[0024] Figure 4 Another schematic diagram of the structure of the measurement system provided by the embodiment of the present invention.

[0025] Figure 5 A schematic diagram of another structure of an optical fiber device provided in an embodiment of the present invention.

[0026] Figure 6 Another schematic diagram of the structure of the optical fiber device provided in an embodiment of the present invention.

[0027] Figure 7 A further structural schematic diagram of a measurement system provided by an embodiment of the present invention.

[0028] Main component numbers:

[0029] 1. first signal light; 2. second signal light; 3. third signal light; 4. fourth signal light; 5. fifth signal light; 6. sixth signal light; 7. seventh signal light; 10. optical fiber device; 20. measuring device; 11. packaging shell; 12. first optical fiber port; 121. first collimator; 13. second optical fiber port; 131. second collimator; 14. half-wave plate; 15. polarization beam splitter; 16. fourth optical fiber port; 161. fourth collimator; 17. third optical fiber port; 171. third collimator; 21. fifth optical fiber port; 211. fifth collimator; 22. quarter-wave plate; 23. reflector. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments described in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the protection scope of the present invention.

[0031] It should be noted that all directional indications (such as up, down, left, right, front, back, top, and bottom) in the embodiments of the present invention are only used to explain the relative position relationship, movement, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly. In addition, the term "vertical" involved in the embodiments of the invention and the claims means that the angle between the two elements is 90° or there is a deviation of -5° to +5°, and the term "parallel" involved means that the angle between the two elements is 0° or there is a deviation of -5° to +5°.

[0032] In the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0033] See also Figure 1 and Figure 2 An embodiment of the present invention provides an optical fiber device 10 and a measurement system, and the measurement system includes the optical fiber device 10 and a measurement device 20.

[0034] Specifically, Figure 1As shown, the optical fiber device 10 may, for example, include a packaging shell 11, a first optical fiber port 12, a second optical fiber port 13, a half-wave plate 14, and a polarization beam splitter prism 15. The packaging shell 11 may, for example, be a rectangular packaging box, a sealed light-proof space is formed in the packaging shell 11, and the first optical fiber port 12 and the second optical fiber port 13 are arranged on the packaging shell 11. The packaging shell 11 may, for example, have a first side wall and a second side wall opposite to each other, the first optical fiber port 12 is arranged on the first side wall, the second optical fiber port 13 is arranged on the second side wall, the first optical fiber port 12 and the second optical fiber port 13 are arranged opposite to each other, the first optical fiber port 12 may, for example, be a light incident port, the action laser may, for example, enter the packaging shell 11 through the first optical fiber port 12, the second optical fiber port 13 may, for example, be a light exit port, and the action laser is output from the second optical fiber port 13 after passing through the optical fiber device 10. The half-wave plate 14 is arranged in the packaging shell 11 and is arranged close to the first optical fiber port 12. The polarization beam splitter prism 15 is arranged in the packaging shell 11 and is arranged between the half-wave plate 14 and the second optical fiber port 13. The half-wave plate 14 and the polarization beam splitter prism 15 are arranged in sequence along the incident direction of the light.

[0035] Figure 1 The figure also shows the transmission of the action laser, for example, the first signal light 1, in the optical fiber device 10. The first optical fiber port 12 is used to input the first signal light 1 into the encapsulation shell 11, that is, the first signal light 1 is input into the encapsulation shell 11 through the first optical fiber port 12. The first signal light 1 passes through the half-wave plate 14. The half-wave plate 14 is used to change the polarization state of the first signal light 1 into the second signal light 2. The polarization beam splitter prism 15 is used to transmit the second signal light 2 along the first optical path into the third signal light 3. The third signal light 3 is transmitted to the second optical fiber port 13, and the second optical fiber port 13 outputs the third signal light 3. Inside the encapsulation shell 11, the light is transmitted in free space, and the light in the first optical fiber port 12 and the second optical fiber port 13 is transmitted through optical fiber. Through the arrangement of the optical fiber port, the half-wave plate 14 and the polarization beam splitter prism 15, the output light (that is, the third signal light 3) of the optical fiber device 10 has the characteristics of a high polarization extinction ratio, thereby improving the polarization characteristics of the light, and further improving the calibration efficiency and measurement accuracy of quantum precision measurement.

[0036] The optical fiber device 10 provided in the embodiment of the present invention is provided with a first optical fiber port 12 and a second optical fiber port 13 on the packaging shell 11, and a half-wave plate 14 and a polarization splitter prism 15 are sequentially arranged in the packaging shell 11 along the incident direction of the light. The action laser, for example, the first signal light 1 is input into the packaging shell 11 through the first optical fiber port 12. The first signal light 1 passes through the half-wave plate 14 and then is transmitted through the polarization splitter prism 15 to be output as the third signal light 3, so that the third signal light 3 output by the optical fiber device 10 has the characteristics of a high polarization extinction ratio, thereby improving the polarization characteristics of the light, thereby improving the calibration efficiency and measurement accuracy of quantum precision measurement.

[0037] like Figure 2 As shown, the measuring system may, for example, include the optical fiber device 10 and the measuring device 20 as described above, and the measuring device 20 may, for example, be an atomic clock, a cold atom gravimeter, etc. The measuring device 20 is connected to the second optical fiber port 13 of the optical fiber device 10 through an optical fiber to apply the output light (i.e., the third signal light 3) of the optical fiber device 10. Specifically, the measuring device 20 may, for example, be provided with a fifth optical fiber port 21, and a quarter wave plate 22 and a reflector 23 sequentially arranged along the incident direction of the light, and the fifth optical fiber port 21 and the second optical fiber port 13 are connected through an optical fiber.

[0038] The fifth optical fiber port 21 is used to input the third signal light 3 into the measuring device 20, and the third signal light 3 is transmitted from the second optical fiber port 13 to the fifth optical fiber port 21 through the optical fiber. The third signal light 3 passes through the quarter wave plate 22 and the reflector 23 in sequence, and then is reflected by the reflector 23 and then changes the polarization state through the quarter wave plate 22 to become the seventh signal light 7. The quarter wave plate 22 is used to adjust the polarization state of the third signal light 3 and the seventh signal light 7, and the reflector 23 is used to reflect the third signal light 3. The quarter wave plate 22 and the reflector 23 are used to make the optical paths of the third signal light 3 and the seventh signal light 7 overlap, thereby improving the degree of optical path overlap between the third signal light 3 and the seventh signal light 7, so that the direction of the optical path can be adjusted with high precision, and the calibration efficiency and measurement accuracy of quantum precision measurement are further improved.

[0039] See also Figure 3The packaging shell 11 may, for example, further include a third side wall between the first side wall and the second side wall, and the optical fiber device 10 may further include a third optical fiber port 17, which is disposed on the third side wall of the packaging shell 11. The second optical fiber port 13 is further used to receive the fourth signal light 4 after the third signal light 3 is reflected by the measuring device 20, and the polarization beam splitter prism 15 is further used to reflect the fourth signal light 4 into the fifth signal light 5 along the second optical path, and the fifth signal light 5 is transmitted to the third optical fiber port 17 through free space, and the third optical fiber port 17 is used to output the fifth signal light 5, and the second optical path is perpendicular to the first optical path. Through the setting of the third optical fiber port 17, the third optical fiber port 17 can be used to connect to an optical power detector, so as to determine the degree of overlap between the third signal light 3 and the seventh signal light, and can also adjust the third signal light 3 and the seventh signal light 7 by monitoring the power of the fifth signal light 5 output by the third optical fiber port 17 so that the third signal light 3 and the seventh signal light 7 overlap, thereby improving the degree of overlap between the third signal light 3 and the seventh signal light 7, so that the direction of the optical path can be adjusted with high precision.

[0040] Further, see Figure 4 , the quarter wave plate 22 and the reflector 23 can be, for example, both movably disposed in the measuring device 20, the quarter wave plate 22 is used to adjust the polarization directions of the third signal light 3 and the seventh signal light 7, and the reflector 23 is used to adjust the degree of optical path overlap of the third signal light 3 and the seventh signal light 7. In this embodiment, the degree of optical path overlap of the third signal light 3 and the seventh signal light 7 can be adjusted by adjusting the positions of the quarter wave plate 22 and the reflector 23. When the polarization directions of the third signal light 3 and the seventh signal light 7 are perpendicular to each other, the power of the fifth signal light 5 output from the third optical fiber port 17 is the maximum, and when the polarization directions of the third signal light 3 and the seventh signal light 7 are parallel to each other, the power of the fifth signal light 5 output from the third optical fiber port 17 is the minimum. When adjusting the quarter wave plate 22 and the reflector 23, for example, the position of the reflector 23 can be adjusted first so that the third optical fiber port 17 can output the fifth signal light 5, and then the position of the quarter wave plate 22 can be adjusted so that the power of the fifth signal light 5 is maximized, so that the polarization directions of the third signal light 3 and the seventh signal light 7 are perpendicular to each other, and then the position of the reflector 23 can be further optimized to improve the degree of overlap of the optical paths of the third signal light 3 and the seventh signal light 7. When applied, for example, the third signal light 3 and the seventh signal light 7 can be applied. Through such an arrangement, the polarization characteristics and overlap of the third signal light 3 and the seventh signal light 7 can be improved, thereby improving the calibration efficiency and measurement accuracy of quantum precision measurement.

[0041] See also Figure 5The packaging shell 11 may, for example, further include a fourth side wall disposed opposite to the third side wall. The optical fiber device 10 further includes a fourth optical fiber port 16 disposed on the fourth side wall of the packaging shell 11. The polarization beam splitter prism 15 is further used to reflect the second signal light 2 into the sixth signal light 6 along the third optical path, and can improve the linear polarization characteristics of the sixth signal light 6. The sixth signal light 6 is transmitted to the fourth optical fiber port 16 through free space, and the fourth optical fiber port 16 is used to output the sixth signal light 6. That is, the first signal light 1 changes its polarization state to the second signal light 2 after passing through the half-wave plate 14, and the second signal light 2 is divided into two beams of light through the polarization beam splitter prism 15, one beam is the third signal light 3 after transmission, and the other beam is the sixth signal light 6 after reflection. Through the setting of the fourth optical fiber port 16, it can be used for power monitoring and signal light detection. For example, the power of the first signal light 1 can be controlled by monitoring the power of the sixth signal light 6 output from the fourth optical fiber port 16 to achieve power stability. For example, when the power of the sixth signal light 6 is detected to be small, the power of the first signal light 1 is increased. When the power of the sixth signal light 6 is detected to be large, the power of the first signal light 1 is reduced, thereby achieving power stability. For another example, after the first signal light 1 is input, if the second optical fiber port 13 does not output the third signal light 3, it can be determined by detecting the sixth signal light 6 output from the fourth optical fiber port 16 whether there is a problem with the input of the first signal light 1, so as to determine the cause of the problem and make corresponding adjustments. If the fourth optical fiber port 16 does not detect the output of the sixth signal light 6, it can be determined that there is a problem with the input of the first signal light 1. If the fourth optical fiber port 16 detects that the sixth signal light 6 is output normally, it can be determined that there is no problem with the input of the first signal light 1. Then, it can be determined whether there is a problem with the second optical fiber port 13 for further detection. Of course, this is only an example, and the present embodiment is not limited thereto.

[0042] Further, in one implementation of the present embodiment, the half-wave plate 14 can be, for example, movably connected to the packaging shell 11, that is, the half-wave plate 14 can be rotated to adjust the position, and the power ratio of the third signal light 3 and the sixth signal light 6 can be adjusted by rotating the half-wave plate 14 to be suitable for more application scenarios. In other implementations of the present embodiment, the half-wave plate 14 can also be, for example, located at a fixed position. For example, if the power of the third signal light 3 needs to be maximized, the half-wave plate 14 is fixed at a corresponding position so that the power of the third signal light 3 is maximized and the power of the sixth signal light 6 is minimized, so that it can be directly applied without adjustment, and the convenience of use that meets a single requirement can be met.

[0043] See also Figure 6In this embodiment, the optical fiber device 10 may, for example, further include a first collimator 121 and a second collimator 131. The first collimator 121 is disposed on the first optical fiber port 12. The first collimator 121 is used to convert the first signal light 1 of the first optical fiber port 12 into a collimated light beam and input it into the packaging shell 11. The second collimator 131 is disposed on the second optical fiber port 13. The second collimator 131 is used to couple the third signal light 3 to the second optical fiber port 13 for output. The optical fiber device 10 may, for example, further include a third collimator 171. The third collimator 171 is disposed on the third optical fiber port 17. The third collimator 171 is used to couple the fifth signal light 5 to the third optical fiber port 17 for output. The optical fiber device 10 may, for example, further include a fourth collimator 161. The fourth collimator 161 is disposed on the fourth optical fiber port 16. The fourth collimator 161 is used to couple the sixth signal light 6 to the fourth optical fiber port 16 for output. See FIG. Figure 7 , the measuring device 20 may also include, for example, a fifth collimator 211, which is arranged at the fifth optical fiber port 21, and is used to convert the third signal light 3 of the fifth optical fiber port 21 into a collimated light beam and input it into the measuring device 20, and couple the seventh signal light 7 to the fifth optical fiber port 21 for output. That is, the transmission between the optical fiber and the free space may be provided with a collimator, for example. In one implementation of the present embodiment, the first optical fiber port 12, the second optical fiber port 13, the third optical fiber port 17 and the fourth optical fiber port 16 may be provided, for example, to connect the optical fiber to the collimator, and a plug connector is provided at the other end of the optical fiber to connect other external optical fiber interfaces, such as an optical fiber flange. For example, the fifth optical fiber port 21 is provided with an optical fiber flange on the fifth collimator 21, and the optical fiber plug connector of the second optical fiber port 13 is plugged into the optical fiber flange, thereby realizing the connection between the second optical fiber port 13 and the fifth optical fiber port 21. Of course, the first optical fiber port 12, the second optical fiber port 13, the third optical fiber port 17 and the fourth optical fiber port 16 can also be connected by, for example, setting an optical fiber flange on the collimator and connecting the optical fiber flanges with an optical fiber connecting line. The specific setting can be based on actual needs, and the present embodiment is not limited thereto.

[0044] The optical fiber device 10 provided in the embodiment of the present invention can provide a multi-port, high extinction ratio, and multifunctional optical fiber device 10 by setting a half-wave plate 14, a polarization beam splitter prism 15, and a first optical fiber port 12, a second optical fiber port 13, a third optical fiber port 17, and a fourth optical fiber port 16. The third signal light 3 outputted from the second optical fiber port 13 has the characteristic of a high polarization extinction ratio, thereby improving the polarization characteristics of the third signal light 3, thereby improving the calibration efficiency and measurement accuracy of quantum precision measurement; the power intensity can be monitored through the third optical fiber port 17, so that the light overlap degree of the third signal light and the seventh signal light can be increased by adjustment, so that the direction of the optical path can be adjusted with high precision, further improving the calibration efficiency and measurement accuracy of quantum precision measurement; the fourth optical fiber port 16 can be used for power monitoring, and the power distribution of the third signal light 3 and the sixth signal light 6 can be adjusted through the half-wave plate 14.

[0045] In addition, it can be understood that the aforementioned embodiments are only exemplary descriptions of the present invention. Under the premise that the technical features do not conflict, the structures do not contradict, and the purpose of the present invention is not violated, the technical solutions of the various embodiments can be arbitrarily combined and used in combination.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An optical fiber device, characterized in that: include: A packaging shell having a first side wall and a second side wall opposite to each other; A first optical fiber port is provided on the first side wall of the packaging shell, and the first optical fiber port is a light incident port; A second optical fiber port is provided on the second side wall of the packaging shell, and the second optical fiber port is a light emitting port; A half-wave plate, disposed in the packaging shell and close to the first optical fiber port; A polarization beam splitter prism is arranged in the packaging shell, the polarization beam splitter prism is arranged between the half-wave plate and the second optical fiber port, and the half-wave plate and the polarization beam splitter prism are arranged in sequence along the incident direction of the light; Among them, the first optical fiber port is used to input the first signal light into the packaging shell; the half-wave plate is used to change the polarization state of the first signal light into the second signal light, the polarization beam splitter prism is used to transmit the second signal light along the first optical path into the third signal light, and the second optical fiber port is used to output the third signal light.

2. The optical fiber device according to claim 1, characterized in that: Also includes: A first collimator, disposed on the first optical fiber port, the first collimator is used to convert the first signal light of the first optical fiber port into a collimated light beam and input it into the packaging shell; The second collimator is disposed on the second optical fiber port, and is used to couple the third signal light to the second optical fiber port for output.

3. The optical fiber device according to claim 1, characterized in that: The packaging shell further comprises a third side wall located between the first side wall and the second side wall; the optical fiber device further comprises: A third optical fiber port is disposed on the third side wall of the packaging shell; The second optical fiber port is also used to receive a fourth signal light after the third signal light is reflected by a measuring device, the polarization beam splitter is also used to reflect the fourth signal light into a fifth signal light along a second optical path, the third optical fiber port is used to output the fifth signal light, and the second optical path is perpendicular to the first optical path.

4. The optical fiber device according to claim 3, characterized in that: The packaging shell further comprises a fourth side wall arranged opposite to the third side wall; the optical fiber device further comprises: a fourth optical fiber port, disposed on the fourth side wall of the packaging shell; The polarization beam splitter prism is further used to reflect the second signal light into a sixth signal light along a third optical path, and the fourth optical fiber port is used to output the sixth signal light.

5. The optical fiber device according to claim 4, characterized in that: The half-wave plate is movably connected to the packaging shell, and the half-wave plate is used to adjust the power ratio of the third signal light and the sixth signal light.

6. The optical fiber device according to claim 4, characterized in that: Also includes: A third collimator is disposed on the third optical fiber port, and the third collimator is used to couple the fifth signal light to the third optical fiber port for output; as well as A fourth collimator is disposed at the fourth optical fiber port, and is used to couple the sixth signal light to the fourth optical fiber port for output.

7. A measurement system, characterized in that: include: The optical fiber device according to any one of claims 1 to 6; as well as A measuring device is connected to the second optical fiber port of the optical fiber device through an optical fiber.

8. The measuring system according to claim 7, characterized in that The measuring device is provided with a fifth optical fiber port, the fifth optical fiber port and the second optical fiber port are connected through an optical fiber, and a quarter wave plate and a reflector are sequentially arranged in the measuring device along the incident direction of light; The fifth optical fiber port is used to input the third signal light into the measuring device. The third signal light passes through the quarter wave plate and the reflector in sequence, and becomes the seventh signal light after being reflected by the reflector and then changing the polarization state through the quarter wave plate. The quarter wave plate and the reflector are used to make the optical paths of the third signal light and the seventh signal light coincide. The fifth optical fiber port is also used to output the seventh signal light to the second optical fiber port.

9. The measuring system according to claim 8, characterized in that The quarter wave plate and the reflector are both movably arranged in the measuring device, the quarter wave plate is used to adjust the polarization directions of the third signal light and the seventh signal light, and the reflector is used to adjust the degree of optical path overlap between the third signal light and the seventh signal light.

10. The measuring system according to claim 9, characterized in that Also includes: A fifth collimator is arranged at the fifth optical fiber port, and is used for converting the third signal light of the fifth optical fiber port into a collimated light beam to input into the measuring device, and coupling the seventh signal light to the fifth optical fiber port for output.

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