Optical sensor

Abstract

An optical sensor, comprising a laser light source, a filtering device used for filtering laser light, a sensing device used for sensing external factors, and a measurement device at least used for measuring the number of longitudinal modes of the laser light. The sensing device is connected to the filtering device, and the measurement device is arranged on an output path of the filtering device. Laser light of the laser light source is filtered by the filtering device and then outputted, and is transmitted to the measurement device for measurement. The filtering device, the sensing device, and the measurement device are provided, and the sensing device senses environmental factors and exerts an influence on the filtering device, so that a bandpass position and / or a bandpass width of the filtering device changes, thereby affecting the number of longitudinal modes and / or longitudinal mode positions of laser light outputted after the laser light passes through the filtering device. The measurement module measures changes in the number of longitudinal modes and / or longitudinal mode positions of the laser light, thereby enabling measurement and monitoring of extremely small changes in external factors. The present invention has high measurement accuracy and a wide application range.

Description

Optical sensor TECHNICAL FIELD

[0001] The present application relates to the field of optical technology, more particularly to an optical sensor. BACKGROUND

[0002] As one of the foundations of information technology, sensor technology plays a vital role in the development of the Internet of Things and information technology, and is highly concerned and researched by countries around the world.

[0003] With the complication and diversification of application scenarios, the market has higher and higher requirements for the detection accuracy of sensors. The traditional sensor technology based on electrical principle has large transmission loss and is easily disturbed by external electromagnetic field, thus having great disadvantages, and its application is greatly limited in many special environments, and the accuracy is low, which cannot meet the use requirements.

[0004] The above shortcomings still need to be improved. TECHNICAL PROBLEM

[0005] The purpose of the embodiments of the present application is to provide an optical sensor to solve the technical problem of low measurement accuracy of the sensor in the prior art. TECHNICAL SOLUTION

[0006] To solve the above technical problems, the technical scheme adopted by the embodiments of the present application is to provide an optical sensor, comprising:

[0007] A laser light source for outputting laser light;

[0008] A filtering device for filtering the laser light;

[0009] A sensing device connected to the filtering device for sensing external factors;

[0010] A measuring device provided on the output path of the filtering device, and used for measuring at least the number of longitudinal modes of the laser light.

[0011] In one embodiment, the filtering device comprises a first filtering unit and a second filtering unit for filtering the laser light, and the filtering range of the first filtering unit partially overlaps with the filtering range of the second filtering unit.

[0012] The sensing device is connected to the first filtering unit and / or the second filtering unit.

[0013] In one embodiment, the first filtering unit is a transmission type filtering unit, which is connected to the laser light source and used for transmission filtering of the laser light.

[0014] The second filter unit is a transmissive filter unit, configured to perform transmissive filtering on the laser and output the laser.

[0015] In one embodiment, the first filter unit is a transmissive filter unit, configured to perform transmissive filtering on the laser.

[0016] The second filter unit is a reflective filter unit, configured to perform reflective filtering on the laser.

[0017] In one embodiment, the first filter unit is further configured to be connected with the laser source, and the laser is sequentially transmitted by the first filter unit, reflected by the second filter unit, and then emitted through the first filter unit.

[0018] In one embodiment, the optical sensor further comprises an output unit, configured to output the laser at a side end of the filter device.

[0019] The first filter unit is further configured to be connected with the laser source, and the laser is sequentially transmitted by the first filter unit, reflected by the second filter unit, and then emitted through the output unit.

[0020] In one embodiment, the optical sensor further comprises a coupling unit, configured to couple the laser of the laser source into the filter device.

[0021] The laser is sequentially coupled by the coupling unit, reflected by the second filter unit, and transmitted by the first filter unit, and then emitted.

[0022] In one embodiment, the first filter unit is a reflective filter unit, configured to perform reflective filtering on the laser.

[0023] The second filter unit is a reflective filter unit, configured to perform reflective filtering on the laser.

[0024] The optical sensor further comprises:

[0025] a coupling unit, configured to couple the laser of the laser source into the filter device;

[0026] an output unit, configured to output the laser at a side end of the filter device.

[0027] In one embodiment, the optical sensor further comprises:

[0028] a tuning device, connected with the filter device, configured to adjust a bandpass position and a bandpass width of the filter device.

[0029] In one embodiment, the measuring device comprises:

[0030] The measurement device filtering module is configured to filter the laser light. The laser light output from the measurement device filtering module is single longitudinal mode laser light.

[0031] The measurement device tuning module is connected to the measurement device filtering module and is configured to adjust at least the band-pass position of the measurement device filtering module.

[0032] The measurement device detection module is arranged on the output path of the measurement device filtering module and is configured to detect the laser light.

[0033] In one embodiment, the measurement device filtering module comprises a measurement device first filtering unit and a measurement device second filtering unit, and the measurement device tuning module is connected to the measurement device first filtering unit and / or the measurement device second filtering unit. Advantages

[0034] The optical sensor provided by the embodiments of the present application has the following advantages: the filtering device, the sensing device and the measurement device are arranged. The sensing device senses the environmental factors and has an influence on the filtering device, so that the band-pass position and / or the band-pass width of the filtering device are changed, thereby affecting the number and / or the position of the longitudinal modes of the laser light output from the filtering device. The measurement module measures the changes in the number and / or the position of the longitudinal modes of the laser light, so that the measurement and monitoring of the slight changes of the external factors can be realized, the measurement precision is high, and the application field is wide. BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0036] Fig. 1 is a working principle schematic diagram of the filtering device of the optical sensor provided by the embodiments of the present application;

[0037] Fig. 2 is a working principle schematic diagram of the filtering device of the optical sensor provided by the embodiments of the present application;

[0038] Fig. 3 is a working principle schematic diagram of the filtering device of the optical sensor provided by the embodiments of the present application;

[0039] Fig. 4 is a working principle schematic diagram of the band-pass position adjustment of the tuning module of the optical sensor provided by the embodiments of the present application;

[0040] Fig. 5 is a working principle schematic diagram of the band-pass width adjustment of the tuning module of the optical sensor provided by the embodiments of the present application;

[0041] FIG. 6 is a schematic diagram of a laser emission spectrum of a laser light source of an optical sensor according to an embodiment of the present application;

[0042] FIG. 7 is a schematic diagram of a structure of an optical sensor according to an embodiment of the present application;

[0043] FIG. 8 is a schematic diagram of a structure of an optical sensor according to an embodiment of the present application;

[0044] FIG. 9 is a schematic diagram of a structure of an optical sensor according to an embodiment of the present application;

[0045] FIG. 10 is a schematic diagram of a structure of an optical sensor according to an embodiment of the present application;

[0046] FIG. 11 is a schematic diagram of a structure of an optical sensor according to an embodiment of the present application;

[0047] FIG. 12 is a schematic diagram of a structure of an optical sensor according to an embodiment of the present application;

[0048] FIG. 13 is a schematic diagram of a structure of an optical sensor according to an embodiment of the present application;

[0049] FIG. 14 is a schematic diagram of a structure of an optical sensor according to an embodiment of the present application;

[0050] FIG. 15 is a schematic diagram of a structure of an optical sensor according to an embodiment of the present application;

[0051] FIG. 16 is a schematic diagram of a structure of an optical sensor according to an embodiment of the present application;

[0052] FIG. 17 is a schematic diagram of a structure of an optical sensor according to an embodiment of the present application;

[0053] FIG. 18 is a schematic diagram of a working principle of a filter module of a measuring device of an optical sensor according to an embodiment of the present application;

[0054] FIG. 19 is a schematic diagram of a working principle of a filter module of a measuring device of an optical sensor according to an embodiment of the present application;

[0055] FIG. 20 is a schematic diagram of a working principle of a filter module of a measuring device of an optical sensor according to an embodiment of the present application;

[0056] FIG. 21 is a schematic diagram of a working principle of a band-pass position adjustment of a tuning module of a measuring device of an optical sensor according to an embodiment of the present application;

[0057] FIG. 22 is a schematic diagram of a working principle of a band-pass width adjustment of a tuning module of a measuring device of an optical sensor according to an embodiment of the present application;

[0058] FIG. 23 is a schematic diagram of a laser exit of a filter module of a measurement device of an optical sensor according to an embodiment of the present application;

[0059] FIG. 24 is a schematic diagram of a structure of a measurement device of an optical sensor according to an embodiment of the present application;

[0060] FIG. 25 is a schematic diagram of a structure of a measurement device of an optical sensor according to an embodiment of the present application;

[0061] FIG. 26 is a schematic diagram of a structure of a measurement device of an optical sensor according to an embodiment of the present application;

[0062] FIG. 27 is a schematic diagram of a structure of a measurement device of an optical sensor according to an embodiment of the present application;

[0063] FIG. 28 is a schematic diagram of a structure of a measurement device of an optical sensor according to an embodiment of the present application;

[0064] FIG. 29 is a schematic diagram of a structure of a measurement device of an optical sensor according to an embodiment of the present application;

[0065] FIG. 30 is a schematic diagram of a structure of a measurement device of an optical sensor according to an embodiment of the present application;

[0066] FIG. 31 is a schematic diagram of a structure of a measurement device of an optical sensor according to an embodiment of the present application;

[0067] FIG. 32 is a schematic diagram of a structure of a measurement device of an optical sensor according to an embodiment of the present application. Embodiments of the present application

[0068] In order to make the technical problems to be solved, technical solutions and beneficial effects of the present application clearer, further detailed description will be made to the present application in combination with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0069] It should be noted that when a component is referred to as "fixed to" or "disposed on" another component, it can be directly or indirectly on the other component. When a component is referred to as "connected to" another component, it can be directly or indirectly connected to the other component. The terms "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate the orientation or position based on the orientation or position shown in the drawings, and are only for the convenience of description, and cannot be understood as a limitation on the technical solutions. The terms "first", "second" are only for the purpose of convenient description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features. The meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0070] Fig. 1 to Fig. 32 are structural schematic diagrams of an optical sensor provided by the embodiment.

[0071] Referring to Fig. 7, an optical sensor comprises a laser light source 10 for outputting laser light, a filtering device 20 for filtering the laser light, a sensing device 30 for sensing an external factor, and a measuring device 40 for measuring at least the number of longitudinal modes of the laser light, the sensing device 30 is connected to the filtering device 20, and the measuring device 40 is arranged on an output path of the filtering device 20. The laser light generated by the laser light source 10 is filtered by the filtering device 20 and then transmitted to the measuring device 40 for measurement.

[0072] The working principle of the optical sensor provided by the embodiment is as follows:

[0073] The laser light generated by the laser light source 10 is transmitted to the filtering device 20 for filtering and then transmitted to the measuring device 40 for measurement, so as to obtain the number of longitudinal modes of the laser light;

[0074] When the external factor (such as temperature, pressure, stress, etc.) changes, the sensing device 30 senses the change of the external factor and has an influence on the filtering device 20, so that the passband position and / or the passband width of the filtering device 20 changes, and thus the number and / or position of the longitudinal modes of the laser light changes when the laser light is filtered by the filtering device 20 and then emitted, and the measuring device 40 measures the laser light, so as to obtain the number of longitudinal modes of the laser light;

[0075] Through the change of the number and / or position of the longitudinal modes of the laser light, the corresponding external factor can be obtained, so that the external factor can be monitored.

[0076] In one embodiment, the external factor is temperature, and the temperature has an influence on the filtering device 20, so that the passband position and / or the passband width changes. Through the change of the number and / or position of the longitudinal modes measured by the measuring device 40, the corresponding temperature and / or temperature change information can be obtained, so that the temperature can be monitored.

[0077] In one embodiment, the external factor is pressure, and the pressure has an influence on the filtering device 20, so that the passband position and / or the passband width changes. Through the change of the number and / or position of the longitudinal modes measured by the measuring device 40, the corresponding pressure and / or pressure change information can be obtained, so that the pressure can be monitored.

[0078] In one embodiment, the external factor is stress, which can affect the filter device 20, so that the passband position and / or the passband width are changed. The change of the number of longitudinal modes and / or the longitudinal mode position measured by the measuring device 40 can be used to obtain the corresponding stress and / or stress change, so that the stress can be monitored.

[0079] It should be understood that the external factor is not limited to the above, but can also be other factors, which are not limited herein.

[0080] The optical sensor provided by the embodiment has the beneficial effect that the filter device 20, the sensing device 30 and the measuring device 40 are arranged, the sensing device 30 senses the environmental factor and affects the filter device 20, so that the passband position and / or the passband width of the filter device 20 are changed, which further affects the number of longitudinal modes and / or the longitudinal mode position of the laser output by the filter device 20, and the change of the number of longitudinal modes and / or the longitudinal mode position of the laser is measured by the measuring device 40, so that the measurement and monitoring of the slight change of the external factor can be realized, the measurement precision is high, and the application field is wide.

[0081] Please refer to FIG. 8, further, the filter device 20 includes a first filter unit 201 and a second filter unit 202 for filtering the laser, the filtering range of the first filter unit 201 partially overlaps the filtering range of the second filter unit 202; the sensing device 30 is connected with the first filter unit 201 and / or the second filter unit 202. The filtering described in the embodiment is frequency filtering, and the frequency range of the output laser is the overlapping part of the filtering range of the first filter unit 201 and the filtering range of the second filter unit 202 (please refer to the filtering range L30 in FIG. 6). Through the sensing device 30, the first filter unit 201 or the second filter unit 202 connected therewith can be affected, so that the overlapping position and / or range of the filtering range of the first filter unit 201 and the filtering range of the second filter unit 202 is affected, that is, the passband position and / or the passband width of the filter device 20 is affected, which further affects the number of longitudinal modes and / or the longitudinal mode position of the laser output by the filter device 20.

[0082] Please refer to FIG. 1 and FIG. 8, in one embodiment, the first filter unit 201 is a transmission filter unit for transmitting the laser, the first filter unit 201 is connected with the laser source 10, so that part of the laser generated by the laser source 10 can enter the filter device 20 through the first filter unit 201; the second filter unit 202 is a transmission filter unit for transmitting the laser, part of the laser in the filter device 20 is transmitted after passing through the second filter unit, so that the laser is output.

[0083] The laser light generated by the laser light source 10 passes through the first filtering unit 201. Due to the reflectivity of the first filtering unit 201 in the frequency domain, the laser light within the reflection range of the first filtering unit 201 (i.e., the first reflection range L11) is filtered and cannot pass through the first filtering unit 201, while the laser light outside the first reflection range L11 passes through the first filtering unit 201 and enters the filtering device 20. The laser light entering the filtering device 20 continues to propagate to the second filtering unit 202. Due to the reflectivity of the second filtering unit 202 in the frequency domain, the laser light within the reflection range of the second filtering unit 202 (i.e., the second reflection range L21) is filtered and cannot pass through the second filtering unit 202, while the laser light outside the second reflection range L21 passes through the second filtering unit 202 and is emitted. The part of the frequency domain outside the first reflection range L11 and the frequency domain outside the second reflection range L21 overlap, which is the filtering range L30. The laser light output after passing through the second filtering unit 202 is the laser light of the filtering range L30.

[0084] It should be understood that the first filtering unit 201 can also transmit part of the laser light, and the part of the laser light that cannot be transmitted will be absorbed by the first filtering unit 201; the second filtering unit 202 can also transmit part of the laser light, and the part of the laser light that cannot be transmitted will be absorbed by the second filtering unit 202.

[0085] Please refer to FIG. 2. In an embodiment, the first filtering unit 201 is a transmission type filtering unit for transmitting filtering of laser light, the reflection range of the first filtering unit 201 is the first reflection range L11, and the laser light outside the first reflection range L11 passes through the first filtering unit 201 and enters or is emitted from the filtering device 20; the second filtering unit 202 is a reflection type filtering unit for reflecting filtering of laser light, the transmission range of the second filtering unit 202 is the second transmission range L22, and the laser light outside the second transmission range L22 is reflected at the second filtering unit 202; the part of the frequency domain outside the first reflection range L11 and the frequency domain outside the second transmission range L22 overlap, which is the filtering range L30. The laser light output after passing through the filtering device 20 is the laser light of the filtering range L30.

[0086] Please refer to FIG. 2 and FIG. 9. In an embodiment, the first filtering unit 201 is a transmission type filtering unit, and the second filtering unit 202 is a reflection type filtering unit. The first filtering unit 201 is connected with the laser light source 10, so that the laser light of the laser light source 10 can pass through the first filtering unit 201 and enter the filtering device 20. The laser light entering the filtering device 20 continues to propagate to the second filtering unit 202 and is reflected. Part of the reflected laser light returns to the first filtering unit 201 and is filtered by the first filtering unit 201 and emitted. The output laser light is the laser light of the filtering range L30.

[0087] It should be understood that the first filtering unit 201 can also make part of the laser light be transmitted, and the part of the laser light that cannot be transmitted is absorbed by the first filtering unit 201; the second transmission range L22 of the second filtering unit 202 can also be an absorption range, that is, the laser light in the range is absorbed by the second filtering unit 202.

[0088] Please refer to FIG. 2, FIG. 10 to FIG. 11, in an embodiment, the first filtering unit 201 is a transmission type filtering unit, the second filtering unit 202 is a reflection type filtering unit, and the optical sensor further comprises a first coupling unit 50, the first coupling unit 50 is connected with the first filtering unit 201, and the first coupling unit 50 is connected with the laser light source 10, so as to couple the laser light of the laser light source 10 into the filtering device 20, at this time, the laser light transmitted by the first filtering unit 201 can be directly emitted out of the first filtering unit 201, or transmitted to the first coupling unit 50 and then emitted out. Please refer to FIG. 12, the first coupling unit 50 can also be located in the filtering device 20, and the first coupling unit 50 is connected with the laser light source 10, so as to couple the laser light of the laser light source 10 into the filtering device 20, the laser light enters the filtering device 20 first, is reflected at the second filtering unit 202, and then the part of the laser light reflected returns to the first filtering unit 201 and is filtered by the first filtering unit 201 and then emitted out, and the output laser light is the laser light in the filtering range L30.

[0089] Please refer to FIG. 13, in an embodiment, the first filtering unit 201 is a transmission type filtering unit, the first filtering unit 201 is connected with the laser light source 10, the second filtering unit 202 is a reflection type filtering unit, and the optical sensor further comprises a first output unit 60 for outputting the laser light at the side end of the filtering device 20. The laser light of the laser light source 10 is transmitted by the first filtering unit 201, reflected by the second filtering unit 202, and then emitted out of the first output unit 60, and the output laser light is the laser light in the filtering range L30. The first output unit 60 can also be located outside the filtering device 20 and connected with the first filtering unit 201, so that the laser light is transmitted by the first filtering unit 201, reflected by the second filtering unit 202, and then transmitted by the first filtering unit 201 and emitted out of the first output unit 60.

[0090] Please refer to FIG. 3 and FIG. 14, in one embodiment, the first filter unit 201 is a reflective filter unit for reflecting the laser, the transmission range of the first filter unit 201 is the first transmission range L12, and the laser outside the first transmission range L12 is reflected at the first filter unit 201; the second filter unit 202 is a reflective filter unit for reflecting the laser, the transmission range of the second filter unit 202 is the second transmission range L22, and the laser outside the second transmission range L22 is reflected at the second filter unit 202; the part of the frequency domain outside the first transmission range L12 and the frequency domain outside the second transmission range L22 that overlap is the filter range L30, and the laser output after passing through the filter device 20 is the laser of the filter range L30.

[0091] The optical sensor further comprises a first coupling unit 50 and a first output unit 60, the first coupling unit 50 is located in the filter device 20, and the first coupling unit 50 is connected with the laser light source 10, so as to couple the laser of the laser light source 10 into the filter device 20; the first output unit 60 is used for outputting the laser at the side end of the filter device 20. The laser of the laser light source 10 enters the filter device 20 through the first coupling unit 50, and is output through the first output unit 60 after being reflected by the first filter unit 201 and the second filter unit 202, and the output laser is the laser of the filter range L30. It should be understood that the first transmission range L12 of the first filter unit 201 can also be an absorption range, that is, the laser in the range is absorbed by the first filter unit 201; the second transmission range L22 of the second filter unit 202 can also be an absorption range, that is, the laser in the range is absorbed by the second filter unit 202.

[0092] Please refer to FIG. 15, further, the optical sensor provided by the embodiment further comprises a tuning device 70 connected with the filter device 20, which is used for adjusting the bandpass position and the bandpass width of the filter device 20.

[0093] In one embodiment, the tuning device 70 comprises a first tuning unit 701 connected with the first filter unit 201, which is used for adjusting the bandpass position and the bandpass width of the first filter unit 201. By adjusting the bandpass position of the first filter unit 201, the bandpass position of the overlapping part of the first filter unit 201 and the second filter unit 202 can be adjusted; by adjusting the bandpass width of the first filter unit 201, the bandpass width of the overlapping part of the first filter unit 201 and the second filter unit 202 can be adjusted.

[0094] In one embodiment, the tuning device 70 comprises a second tuning unit 702, which is connected with the second filtering unit 202, for adjusting the band-pass position and / or the band-pass width of the second filtering unit 202. By adjusting the band-pass position of the second filtering unit 202, the band-pass position of the overlapping part of the first filtering unit 201 and the second filtering unit 202 can be adjusted; by adjusting the band-pass width of the second filtering unit 202, the band-pass width of the overlapping part of the first filtering unit 201 and the second filtering unit 202 can be adjusted.

[0095] Referring to FIG. 16, in one embodiment, the tuning device 70 comprises a first tuning unit 701 connected with the first filtering unit 201 and a second tuning unit 702 connected with the second filtering unit 202. By adjusting the band-pass position of the first filtering unit 201 and the second filtering unit 202, the band-pass position of the overlapping part of the first filtering unit 201 and the second filtering unit 202 can be adjusted (see FIG. 4, L30' is the band-pass position before adjustment, and L30 is the band-pass position after adjustment); by adjusting the band-pass width of the first filtering unit 201 and the second filtering unit 202, the band-pass width of the overlapping part of the first filtering unit 201 and the second filtering unit 202 can be adjusted (see FIG. 5, L30' is the band-pass width before adjustment, and L30 is the band-pass width after adjustment). The first tuning unit 701 is connected with the first filtering unit 201, and the second tuning unit 702 is connected with the second filtering unit 202, and by affecting the physical properties of the gratings (including temperature, stress, pressure, etc.), the adjustment of the band-pass position and the band-pass width can be realized to meet the specific use requirements.

[0096] Referring to FIG. 17, further, the optical sensor provided in the embodiment can comprise a first isolating unit 80 arranged on the output path of the filtering device 20, which is arranged between the filtering device 20 and the measuring device 40, for isolating the reverse laser light, thereby protecting the optical sensor.

[0097] Further, the optical sensor provided in the embodiment can further comprise a first circulator arranged on the output path of the filtering device 20, which can be used for outputting laser light and can also be used for returning the laser light to the filtering device 20.

[0098] Further, the first filtering unit 201 can be a high-reflection fiber Bragg grating, and the second filtering unit 202 can also be a high-reflection fiber Bragg grating. Because of the reflection property of the frequency domain of the high-reflection fiber Bragg grating, the light (including laser light) in the reflection range of the frequency domain is filtered.

[0099] Referring to FIG. 24, further, the measuring device 40 comprises a measuring device filtering module 401 for filtering the laser, a measuring device tuning module 402 for adjusting the band-pass position and the band-pass width of the measuring device filtering module 401, and a measuring device detecting module 403 for detecting the longitudinal modes of the laser. The laser output from the measuring device filtering module 401 is single longitudinal mode laser, the measuring device tuning module 402 is connected with the measuring device filtering module 401, and the measuring device detecting module 403 is arranged on the output path of the measuring device filtering module 401. The laser from the filtering device 20 is filtered by the measuring device filtering module 401 and then output and transmitted to the measuring device detecting module 403 for measurement. In this embodiment, the measuring device detecting module 403 is used for detecting whether there is laser output; in the detection process, the single longitudinal mode laser signal detected by the measuring device detecting module 403 appears and disappears in a cycle, and the number of longitudinal modes is obtained by recording the number of times of appearing single longitudinal mode laser signal.

[0100] When the longitudinal modes of the laser need to be measured, first, the band-pass position of the measuring device filtering module 401 is adjusted by the measuring device tuning module 402, so that the band-pass position of the measuring device filtering module 401 is outside the frequency of the laser, at this time, the measuring device detecting module 403 cannot detect laser output. The laser from the filtering device 20 enters the measuring device filtering module 401, is filtered by the measuring device filtering module 401 and then output and transmitted to the measuring device detecting module 403, and the measuring device detecting module 403 detects whether there is laser output. In the detection process, the band-pass position of the measuring device filtering module 401 is adjusted by the measuring device tuning module 402, so that the band-pass position scans the frequency range of the laser in turn (the scanning order can be from low frequency to high frequency, or from high frequency to low frequency). When the longitudinal mode of the laser is in the band-pass range of the measuring device filtering module 401, the laser with the longitudinal mode is output to the measuring device detecting module 403, and the measuring device detecting module 403 detects laser output. After the band-pass position of the measuring device filtering module 401 scans the frequency range of the laser, the measuring device detecting module 403 records the number of times of laser output, so that the number of longitudinal modes can be obtained.

[0101] The measurement device filtering module 401 is configured to filter the laser, so that the single longitudinal mode laser is obtained after the laser passes through the measurement device filtering module 401, and the measurement device tuning module 402 is configured to adjust the band-pass position of the measurement device filtering module 401, so that the frequency range of the laser can be scanned in sequence, and the measurement device detection module 403 is configured to detect the number of times of laser output, so that the number of longitudinal modes is obtained; when the external factors change, the number and / or position of the longitudinal modes in the laser change, so that the number and / or position of the longitudinal modes detected by the measurement device detection module 403 change, the measurement and monitoring of the small change of the external factors can be realized, the measurement precision is high, and the application field is wide.

[0102] Referring to FIG. 23, further, the measurement device tuning module 402 is further configured to adjust the measurement device band-pass width L60 of the measurement device filtering module 401, so that the band-pass width L60 of the measurement device filtering module 401 is narrow enough, and is smaller than the width L61 between the adjacent longitudinal modes in the multi-longitudinal mode laser, so that the laser output after passing through the measurement device filtering module 401 is ensured to be the single longitudinal mode laser.

[0103] Referring to FIG. 25, in an embodiment, the measurement device filtering module 401 includes a measurement device first filtering unit 4011 and a measurement device second filtering unit 4012 configured to filter the laser, the measurement device tuning module 402 is connected with the measurement device first filtering unit 4011 and / or the measurement device second filtering unit 4012, so that the band-pass position and / or the band-pass width of the measurement device first filtering unit 4011 and / or the measurement device second filtering unit 4012 can be adjusted. The filtering range of the measurement device first filtering unit 4011 and the filtering range of the measurement device second filtering unit 4012 partially overlap, the single longitudinal mode laser is obtained after the laser is filtered by the measurement device first filtering unit 4011 and the measurement device second filtering unit 4012, and is output to the measurement device detection module 403.

[0104] The adjustment mode of the measurement device tuning module 402 at least includes:

[0105] adjusting the band-pass position and the band-pass width of the measurement device first filtering unit 4011 or the measurement device second filtering unit 4012;

[0106] adjusting the band-pass position and the band-pass width of the measurement device first filtering unit 4011 and the measurement device second filtering unit 4012;

[0107] adjusting the band-pass position of the measurement device first filtering unit 4011 and adjusting the band-pass width of the measurement device second filtering unit 4012;

[0108] The bandpass width of the first filter unit 4011 of the measuring device is adjusted, and the bandpass position of the second filter unit 4012 of the measuring device is adjusted.

[0109] Since the two filter units (the first filter unit 4011 of the measuring device and the second filter unit 4012 of the measuring device) in the filter module 401 of the measuring device have partially overlapped filter ranges, even if the filter range of each filter unit is wide, a laser with an extremely narrow line width can be obtained by adjusting the first filter unit 4011 of the measuring device and / or the second filter unit 4012 of the measuring device through the tuning module 402 of the measuring device, and thus single-longitudinal-mode filtering output can be realized. Since the filter range requirement of each filter unit is not high, a filter unit with lower parameters and a wider filter range can be used, which greatly reduces the process difficulty.

[0110] In one embodiment, the tuning module 402 of the measuring device includes a first tuning unit 4021 of the measuring device, which is connected with the first filter unit 4011 of the measuring device and is used to adjust the bandpass position and / or the bandpass width of the first filter unit 4011 of the measuring device. By adjusting the bandpass position of the first filter unit 4011 of the measuring device, the bandpass position of the overlapped part of the first filter unit 4011 of the measuring device and the second filter unit 4012 of the measuring device can be adjusted; by adjusting the bandpass width of the first filter unit 4011 of the measuring device, the bandpass width of the overlapped part of the first filter unit 4011 of the measuring device and the second filter unit 4012 of the measuring device can be adjusted.

[0111] In one embodiment, the tuning module 402 of the measuring device includes a second tuning unit 4022 of the measuring device, which is connected with the second filter unit 4012 of the measuring device and is used to adjust the bandpass position and / or the bandpass width of the second filter unit 4012 of the measuring device. By adjusting the bandpass position of the second filter unit 4012 of the measuring device, the bandpass position of the overlapped part of the first filter unit 4011 of the measuring device and the second filter unit 4012 of the measuring device can be adjusted; by adjusting the bandpass width of the second filter unit 4012 of the measuring device, the bandpass width of the overlapped part of the first filter unit 4011 of the measuring device and the second filter unit 4012 of the measuring device can be adjusted.

[0112] Referring to FIG. 25, in an embodiment, the measurement device tuning module 402 comprises a measurement device first tuning unit 4021 and a measurement device second tuning unit 4022, the measurement device first tuning unit 4021 is connected with the measurement device first filter unit 4011, and the measurement device second tuning unit 4022 is connected with the measurement device second filter unit 4012. By adjusting the band-pass position of the measurement device first filter unit 4011 and the measurement device second tuning unit 4022, the band-pass position of the overlapping part of the measurement device first filter unit 4011 and the measurement device second filter unit 4012 can be adjusted (see FIG. 21, L60' is the band-pass position before adjustment, and L60 is the band-pass position after adjustment); by adjusting the band-pass width of the measurement device first filter unit 4011 and the measurement device second filter unit 4012, the band-pass width of the overlapping part of the measurement device first filter unit 4011 and the measurement device second filter unit 4012 can be adjusted (see FIG. 22, L60' is the band-pass width before adjustment, and L60 is the band-pass width after adjustment).

[0113] Referring to FIG. 18 and FIG. 25, in an embodiment, the measurement device first filter unit 4011 is a transmission filter unit for transmitting filtering of laser, and a part of the laser from the filtering device 20 enters the measurement device filtering module 401 through the measurement device first filter unit 4011; the measurement device second filter unit 4012 is a transmission filter unit for transmitting filtering of laser, and part of the laser in the measurement device filtering module 401 is transmitted after passing through the second filter unit, thereby outputting to the measurement device detection module 403.

[0114] The laser passes through the first filtering unit 4011 of the measuring device. Due to the reflectivity of the first filtering unit 4011 of the measuring device in the frequency domain, the laser within the reflection range of the first filtering unit 4011 of the measuring device (i.e., the first reflection range L41 of the measuring device) is filtered and cannot pass through the first filtering unit 4011 of the measuring device, while the laser outside the first reflection range L41 of the measuring device passes through the first filtering unit 4011 of the measuring device and enters the filtering module 401 of the measuring device. The laser entering the filtering module 401 of the measuring device continues to propagate to the second filtering unit 4012 of the measuring device. Due to the reflectivity of the second filtering unit 4012 of the measuring device in the frequency domain, the laser within the reflection range of the second filtering unit 4012 of the measuring device (i.e., the second reflection range L51 of the measuring device) is filtered and cannot pass through the second filtering unit 4012 of the measuring device, while the laser outside the second reflection range L51 of the measuring device passes through the second filtering unit 4012 of the measuring device and exits. The part of the frequency domain outside the first reflection range L41 of the measuring device and the frequency domain outside the second reflection range L51 of the measuring device overlap, which is the filtering range L60 of the measuring device (the filtering range L60 of the measuring device is smaller than the width between adjacent longitudinal modes in the multi-longitudinal mode laser), and the laser output after passing through the second filtering unit 4012 of the measuring device is the single-longitudinal mode laser of the filtering range L60 of the measuring device.

[0115] It should be understood that the first filtering unit 4011 of the measuring device can also transmit part of the laser, and the part of the laser that cannot be transmitted will be absorbed by the first filtering unit 4011 of the measuring device; the second filtering unit 4012 of the measuring device can also transmit part of the laser, and the part of the laser that cannot be transmitted will be absorbed by the second filtering unit 4012 of the measuring device.

[0116] In one embodiment, the first filtering unit 4011 of the measuring device is a transmission filtering unit for transmitting the laser, the reflection range of the first filtering unit 4011 of the measuring device is the first reflection range L41 of the measuring device, and the laser outside the first reflection range L41 of the measuring device passes through the first filtering unit 4011 of the measuring device or exits from the filtering module 401 of the measuring device; the second filtering unit 4012 of the measuring device is a reflection filtering unit for reflecting the laser, the transmission range of the second filtering unit 4012 of the measuring device is the second transmission range L52 of the measuring device, and the laser outside the second transmission range L52 of the measuring device is reflected at the second filtering unit 4012 of the measuring device; the part of the frequency domain outside the first reflection range L41 of the measuring device and the frequency domain outside the second transmission range L52 of the measuring device overlap, which is the filtering range L60 of the measuring device (the filtering range L60 of the measuring device is smaller than the width between adjacent longitudinal modes in the multi-longitudinal mode laser), and the laser output after passing through the filtering module 401 of the measuring device is the single-longitudinal mode laser of the filtering range L60 of the measuring device.

[0117] Please refer to FIG. 19 and FIG. 26, in an embodiment, the first filter unit 4011 of the measuring device is a transmission filter unit, the second filter unit 4012 of the measuring device is a reflection filter unit, and the laser enters the measuring device filter module 401 through the first filter unit 4011 of the measuring device. The laser entering the measuring device filter module 401 continues to transmit to the second filter unit 4012 of the measuring device to reflect, and the reflected part of the laser returns to the first filter unit 4011 of the measuring device and is filtered by the first filter unit 4011 of the measuring device to exit, and the output laser is the laser of the measuring device filtering range L60.

[0118] It should be understood that the first filter unit 4011 of the measuring device can also make part of the laser transmit, and the part of the laser that cannot transmit will be absorbed by the first filter unit 4011 of the measuring device; the second transmission range L52 of the second filter unit 4012 of the measuring device can also be an absorption range, that is, the laser in the range will be absorbed by the second filter unit 4012 of the measuring device.

[0119] Please refer to FIG. 19, FIG. 27 to FIG. 28, in an embodiment, the first filter unit 4011 of the measuring device is a transmission filter unit, the second filter unit 4012 of the measuring device is a reflection filter unit, and the optical sensor further comprises a second coupling unit 404, the second coupling unit 404 is connected with the first filter unit 4011 of the measuring device, and the second coupling unit 404 couples the laser into the measuring device filter module 401, at this time, the laser transmitted by the first filter unit 4011 of the measuring device can directly exit through the first filter unit 4011 of the measuring device, or exit after transmitting to the second coupling unit 404. Please refer to FIG. 29, the second coupling unit 404 can also be located in the measuring device filter module 401, and the second coupling unit couples the laser into the measuring device filter module 401, the laser enters the measuring device filter module 401 first, and then transmits to the second filter unit 4012 of the measuring device to reflect, and the reflected part of the laser returns to the first filter unit 4011 of the measuring device and is filtered by the first filter unit 4011 of the measuring device to exit, and the output laser is the laser of the measuring device filtering range L60.

[0120] Please refer to FIG. 19 and FIG. 30, in one embodiment, the first filter unit 4011 of the measuring device is a transmission filter unit, the second filter unit 4012 of the measuring device is a reflection filter unit, and the optical sensor further comprises a second output unit 405 for outputting the laser light at the side end of the measuring device filter module 401, and the laser light is transmitted to the measuring device detection module 403 after being emitted by the second output unit 405. The laser light is emitted by the second output unit 405 after being transmitted by the first filter unit 4011 of the measuring device and reflected by the second filter unit 4012 of the measuring device in sequence, and the output laser light is the laser light of the measuring device filter range L60. The second output unit 405 can also be located outside the measuring device filter module 401 and connected with the first filter unit 4011 of the measuring device, so that the laser light is emitted by the second output unit 405 to the measuring device detection module 403 after being transmitted by the first filter unit 4011 of the measuring device, reflected by the second filter unit 4012 of the measuring device, and then transmitted by the first filter unit 4011 of the measuring device in sequence.

[0121] Please refer to FIG. 20 and FIG. 31, in one embodiment, the first filter unit 4011 of the measuring device is a reflection filter unit for reflecting and filtering the laser light, the transmission range of the first filter unit 4011 of the measuring device is the first transmission range L42 of the measuring device, and the laser light outside the first transmission range L42 of the measuring device is reflected at the first filter unit 4011 of the measuring device; the second filter unit 4012 of the measuring device is a reflection filter unit for reflecting and filtering the laser light, the transmission range of the second filter unit 4012 of the measuring device is the second transmission range L52 of the measuring device, and the laser light outside the second transmission range L52 of the measuring device is reflected at the second filter unit 4012 of the measuring device; the part of the frequency domain outside the first transmission range L42 of the measuring device and the frequency domain outside the second transmission range L52 of the measuring device that overlap is the filter range L60, the filter range L60 is smaller than the width between adjacent longitudinal modes in the multi-longitudinal-mode laser light, and the output laser light after passing through the measuring device filter module 401 is the laser light of the measuring device filter range L60.

[0122] The optical sensor further comprises a second coupling unit 404 and a second output unit 405, the second coupling unit 404 is located in the measuring device filter module 401 and couples the laser light into the measuring device filter module 401, and the second output unit 405 is used for outputting the laser light at the side end of the measuring device filter module 401 to the measuring device detection module 403. The laser light from the filter device 20 enters the measuring device filter module 401 through the second coupling unit 404, and is output to the measuring device detection module 403 through the second output unit 405 after being reflected by the first filter unit 4011 of the measuring device and the second filter unit 4012 of the measuring device, and the output laser light is the laser light of the measuring device filter range L60.

[0123] It should be understood that the measurement device first transmission range L42 of the measurement device first filter unit 4011 can also be an absorption range, i.e. the laser light within the range is absorbed by the measurement device first filter unit 4011; the measurement device second transmission range L52 of the measurement device second filter unit 4012 can also be an absorption range, i.e. the laser light within the range is absorbed by the measurement device second filter unit 4012.

[0124] Referring to FIG. 32, further, the optical sensor provided by the embodiment can further include a second isolation unit 406 arranged on the output path of the measurement device filter module 401, the second isolation unit 406 being arranged between the measurement device filter module 401 and the measurement device detection module 403, and used for isolating the reverse laser light, thereby protecting the optical sensor.

[0125] Further, the measurement device first filter unit 4011 can be a high-reflection fiber Bragg grating, and the measurement device second filter unit 4012 can also be a high-reflection fiber Bragg grating. Because of the reflection in the frequency domain of the high-reflection fiber Bragg grating, the light (including laser light) in the reflection range is filtered. The measurement device first tuning unit 4021 is connected with the measurement device first filter unit 4011, and the measurement device second tuning unit 4022 is connected with the measurement device second filter unit 4012. By influencing the physical and chemical properties of the grating (including temperature, stress, pressure, etc.), the tuning of the bandpass position and the bandpass width is realized, thereby meeting the specific use requirements.

[0126] Further, the laser light source 10, the filter device 20, the measurement device 40, etc. can be connected through optical fibers, thereby realizing an all-fiber optical filter, having higher sensitivity, larger dynamic range, faster response speed, etc. Some of the devices can be connected through optical fibers, thereby realizing a partial-fiber optical filter. The optical transmission can also be performed through free space, which is not limited here.

[0127] The above only describes the preferred embodiments of the present application and should not be used to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. An optical sensor, characterized by: The optical sensor comprises: a laser light source for outputting laser light; a filtering device for filtering the laser light; a sensing device connected with the filtering device for sensing external factors; a measuring device arranged on an output path of the filtering device for measuring at least the number of longitudinal modes of the laser light.

2. The optical sensor of claim 1, wherein: The filtering device comprises a first filtering unit and a second filtering unit for filtering the laser light, and a filtering range of the first filtering unit partially overlaps with a filtering range of the second filtering unit. The sensing device is connected with the first filtering unit and / or the second filtering unit.

3. The optical sensor of claim 2, wherein: The first filtering unit is a transmission filtering unit for being connected with the laser light source and for performing transmission filtering on the laser light. The second filtering unit is a transmission filtering unit for performing transmission filtering on the laser light and for outputting the laser light.

4. The optical sensor of claim 2, wherein: The first filtering unit is a transmission filtering unit for performing transmission filtering on the laser light. The second filtering unit is a reflection filtering unit for performing reflection filtering on the laser light.

5. The optical sensor of claim 4, wherein: The first filtering unit is further used for being connected with the laser light source, and the laser light is sequentially transmitted through the first filtering unit, reflected by the second filtering unit, and then emitted through the first filtering unit.

6. The optical sensor of claim 4, wherein: The optical sensor further comprises an output unit for outputting the laser light at a side end of the filtering device. The first filtering unit is further used for being connected with the laser light source, and the laser light is sequentially transmitted through the first filtering unit, reflected by the second filtering unit, and then emitted through the output unit.

7. The optical sensor of claim 4, wherein: The optical sensor further comprises a coupling unit for coupling the laser light of the laser light source into the filtering device. The laser light is sequentially coupled through the coupling unit, reflected by the second filtering unit, and then transmitted through the first filtering unit.

8. The optical sensor of claim 2, wherein: The first filtering unit is a reflection filtering unit for performing reflection filtering on the laser light. The second filtering unit is a reflection filtering unit for performing reflection filtering on the laser light. The optical sensor further comprises: a coupling unit for coupling the laser light of the laser light source into the filtering device; an output unit for outputting the laser light at a side end of the filtering device.

9. The optical sensor of claim 1, wherein: The optical sensor further comprises: a tuning device connected with the filtering device for adjusting a band-pass position and a band-pass width of the filtering device.

10. The optical sensor according to any one of claims 1 to 9, characterized in that: The measuring device comprises: a measuring device filtering module for filtering the laser light, and the laser light outputted after passing through the measuring device filtering module is single longitudinal mode laser light; a measuring device tuning module connected with the measuring device filtering module for adjusting at least a band-pass position of the measuring device filtering module; a measuring device detection module arranged on an output path of the measuring device filtering module for detecting the laser light.

11. The optical sensor of claim 10, wherein: The measuring device filtering module comprises a measuring device first filtering unit and a measuring device second filtering unit for filtering the laser light, and the measuring device tuning module is connected with the measuring device first filtering unit and / or the measuring device second filtering unit.

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