Optical sensor

Abstract

The utility model relates to the technical field of optics, and provides an optical sensor which comprises a laser light source, a filtering device used for filtering laser, a sensing device used for sensing external factors and a measuring device at least used for measuring the number of longitudinal modes of the laser. The measuring device is arranged on an output path of the filtering device; laser of the laser light source is output after being filtered by the filtering device, and is transmitted to the measuring device for measurement; a filtering device, a sensing device and a measuring device are arranged, environmental factors are sensed through the sensing device, the filtering device is influenced, the band-pass position and / or the band-pass width of the filtering device are / is changed, and then the longitudinal mode number and / or the longitudinal mode position of laser output after passing through the filtering device are / is influenced. The measurement module is used for measuring changes of the number and / or the position of longitudinal modes in laser, so that measurement and monitoring of tiny changes of external factors can be achieved, the measurement precision is high, and the application field is wide.

Description

Technical Field

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

[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 has received high attention and research from countries around the world.

[0003] As application scenarios become more complex and diverse, market demands for sensor detection accuracy are increasing. Traditional sensor technology based on electrical principles suffers from high transmission loss and susceptibility to interference from external electromagnetic fields, resulting in significant drawbacks. Its application is severely limited in many special environments, and its low accuracy cannot meet application requirements.

[0004] The above shortcomings need to be improved. Utility Model Content

[0005] The purpose of the utility model is to provide an optical sensor to solve the technical problem of low measurement accuracy of sensors in the prior art.

[0006] To achieve the above objectives, the technical solution adopted in this application is to provide an optical sensor, comprising:

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

[0008] A filtering device, used for filtering the laser;

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

[0010] The measuring device is arranged on the output path of the filtering device and is at least used to measure the number of longitudinal modes of the laser.

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

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

[0013] In one embodiment, the first filtering unit is a transmission filtering unit, which is used to connect to the laser light source and perform transmission filtering on the laser;

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

[0015] In one embodiment, the first filtering unit is a transmission filtering unit that performs transmission filtering on the laser;

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

[0017] In one embodiment, the first filter unit is further configured to be connected to the laser light source, and the laser light is sequentially transmitted through 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 for outputting the laser light at a side end of the filtering device;

[0019] The first filter unit is further configured to be connected to the laser light source. The laser light is sequentially transmitted through 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 for coupling the laser light from the laser light source into the filtering device;

[0021] The laser is reflected by the coupling unit, the second filtering unit, and the first filtering unit in sequence before being emitted.

[0022] In one embodiment, the first filtering unit is a reflective filtering unit that performs reflective filtering on the laser;

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

[0024] The optical sensor further comprises:

[0025] a coupling unit, configured to couple the laser light from the laser light source into the filtering device;

[0026] An output unit is used to output the laser at a side end of the filtering device.

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

[0028] A tuning device is connected to the filtering device and is used to adjust the passband position and passband width of the filtering device.

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

[0030] A measuring device filter module, used for filtering the laser light, wherein the laser light outputted after passing through the measuring device filter module is a single longitudinal mode laser light;

[0031] a measuring device tuning module, connected to the measuring device filtering module, and at least used to adjust the bandpass position of the measuring device filtering module;

[0032] The measuring device detection module is provided on the output path of the measuring device filter module and is used to detect the laser.

[0033] In one embodiment, the measuring device filtering module includes a first measuring device filtering unit and a second measuring device filtering unit for filtering the laser, and the measuring device tuning module is connected to the first measuring device filtering unit and / or the second measuring device filtering unit.

[0034] The beneficial effect of an optical sensor provided by this embodiment is that: a filtering device, a sensing device and a measuring device are provided, and the environmental factors are sensed by the sensing device and affect the filtering device, so that the bandpass position and / or bandpass width of the filtering device changes, thereby affecting the number and / or longitudinal mode position of the laser output after passing through the filtering device. The change in the number and / or longitudinal mode position of the longitudinal mode in the laser is measured by the measuring module, thereby realizing the measurement and monitoring of extremely small changes in external factors, with high measurement accuracy and a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0036] Figure 1 Schematic diagram of the working principle of the filtering device of the optical sensor provided in the embodiment of the present application Figure 1 ;

[0037] Figure 2 Schematic diagram of the working principle of the filtering device of the optical sensor provided in the embodiment of the present application Figure 2 ;

[0038] Figure 3 Schematic diagram of the working principle of the filtering device of the optical sensor provided in the embodiment of the present application Figure 3 ;

[0039] Figure 4 A schematic diagram of the working principle of the bandpass position adjustment of the tuning module of the optical sensor provided in an embodiment of the present application;

[0040] Figure 5 A schematic diagram of the working principle of the bandpass width adjustment of the tuning module of the optical sensor provided in an embodiment of the present application;

[0041] Figure 6 A schematic diagram of the laser emission spectrum of the laser light source of the optical sensor provided in an embodiment of the present application;

[0042] Figure 7 Schematic diagram of the structure of the optical sensor provided in the embodiment of the present application Figure 1 ;

[0043] Figure 8 Schematic diagram of the structure of the optical sensor provided in the embodiment of the present application Figure 2 ;

[0044] Figure 9 Schematic diagram of the structure of the optical sensor provided in the embodiment of the present application Figure 3 ;

[0045] Figure 10 Schematic diagram of the structure of the optical sensor provided in the embodiment of the present application Figure 4 ;

[0046] Figure 11 Schematic diagram of the structure of the optical sensor provided in the embodiment of the present application Figure 5 ;

[0047] Figure 12 Schematic diagram of the structure of the optical sensor provided in the embodiment of the present application Figure 6 ;

[0048] Figure 13 Schematic diagram of the structure of the optical sensor provided in the embodiment of the present application Figure 7 ;

[0049] Figure 14 Schematic diagram of the structure of the optical sensor provided in the embodiment of the present application Figure 8 ;

[0050] Figure 15 Schematic diagram of the structure of the optical sensor provided in the embodiment of the present application Figure 9 ;

[0051] Figure 16 Schematic diagram of the structure of the optical sensor provided in the embodiment of the present application Figure 10 ;

[0052] Figure 17 Schematic diagram of the structure of the optical sensor provided in the embodiment of the present application Figure 10 one;

[0053] Figure 18 Schematic diagram of the working principle of the filter module of the optical sensor measurement device provided in the embodiment of the present application Figure 1 ;

[0054] Figure 19Schematic diagram of the working principle of the filter module of the optical sensor measurement device provided in the embodiment of the present application Figure 2 ;

[0055] Figure 20 Schematic diagram of the working principle of the filter module of the optical sensor measurement device provided in the embodiment of the present application Figure 3 ;

[0056] Figure 21 A schematic diagram of the working principle of the bandpass position adjustment of the tuning module of the measuring device of the optical sensor provided in an embodiment of the present application;

[0057] Figure 22 A schematic diagram of the working principle of the bandpass width adjustment of the tuning module of the measuring device of the optical sensor provided in an embodiment of the present application;

[0058] Figure 23 A schematic diagram of laser emission from a filter module of a measuring device of an optical sensor provided in an embodiment of the present application;

[0059] Figure 24 Schematic diagram of the structure of the measuring device of the optical sensor provided in the embodiment of the present application Figure 1 ;

[0060] Figure 25 Schematic diagram of the structure of the measuring device of the optical sensor provided in the embodiment of the present application Figure 2 ;

[0061] Figure 26 Schematic diagram of the structure of the measuring device of the optical sensor provided in the embodiment of the present application Figure 3 ;

[0062] Figure 27 Schematic diagram of the structure of the measuring device of the optical sensor provided in the embodiment of the present application Figure 4 ;

[0063] Figure 28 Schematic diagram of the structure of the measuring device of the optical sensor provided in the embodiment of the present application Figure 5 ;

[0064] Figure 29 Schematic diagram of the structure of the measuring device of the optical sensor provided in the embodiment of the present application Figure 6 ;

[0065] Figure 30 Schematic diagram of the structure of the measuring device of the optical sensor provided in the embodiment of the present application Figure 7 ;

[0066] Figure 31 Schematic diagram of the structure of the measuring device of the optical sensor provided in the embodiment of the present application Figure 8 ;

[0067] Figure 32 Schematic diagram of the structure of the measuring device of the optical sensor provided in the embodiment of the present application Figure 9 .

[0068] Among them, the reference numerals in the figures are:

[0069] 10-laser light source; 20-filter device;

[0070] 201-first filtering unit; 202-second filtering unit;

[0071] 30-sensing device; 40-measuring device;

[0072] 50-first coupling unit; 60-first output unit;

[0073] 70-tuning device; 701-first tuning unit;

[0074] 702-second tuning unit; 80-first isolation unit;

[0075] 401-measuring device filtering module; 4011-measuring device first filtering unit;

[0076] 4012 - second filter unit of the measuring device; 402 - tuning module of the measuring device;

[0077] 4021 - first tuning unit of the measuring device; 4022 - second tuning unit of the measuring device;

[0078] 403 - measuring device detection module; 404 - second coupling unit;

[0079] 405 - second output unit; 406 - second isolation unit. DETAILED DESCRIPTION

[0080] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, this application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0081] It should be noted that when a component is referred to as being "fixed on" or "disposed on" another component, it may be located directly or indirectly on the other component. When a component is referred to as being "connected to" another component, it may be directly or indirectly connected to the other component. The directions or positions indicated by the terms "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the directions or positions shown in the accompanying drawings and are only for the convenience of description and cannot be understood as limitations on this technical solution. The terms "first" and "second" are only used for the purpose of convenience of description and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features. "Multiple" means two or more, unless otherwise clearly and specifically defined.

[0082] Figures 1 to 32 This is a schematic structural diagram of an optical sensor provided in this embodiment.

[0083] See also Figure 7 An optical sensor includes a laser light source 10 for outputting laser light, a filtering device 20 for filtering the laser light, a sensing device 30 for sensing external factors, and a measuring device 40 for at least measuring 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 provided on the output path of the filtering device 20. The laser light from the laser light source 10 is filtered by the filtering device 20, output, and transmitted to the measuring device 40 for measurement.

[0084] The working principle of the optical sensor provided in this embodiment is as follows:

[0085] The laser light generated by the laser light source 10 is transmitted to the filtering device 20 for filtering, and then the laser light is further transmitted to the measuring device 40 for measurement, thereby obtaining the number of longitudinal modes in the laser light;

[0086] When external factors (such as temperature, pressure, and stress) change, the sensor device 30 senses the change in the external factor and affects the filter device 20, thereby causing the bandpass position and / or bandpass width of the filter device 20 to change, thereby causing the number and / or position of the longitudinal modes of the laser light after being filtered by the filter device 20 to change. The measuring device 40 measures the laser light to obtain the number of longitudinal modes in the laser light.

[0087] By observing the changes in the number and / or position of longitudinal modes in the laser, the corresponding external factors can be known, thereby monitoring the external factors.

[0088] In one embodiment, the external factor is temperature, which affects the filter device 20, thereby causing changes in the passband position and / or passband width. By measuring the changes in the number and / or position of longitudinal modes by the measuring device 40, the corresponding temperature and / or temperature change information can be obtained, thereby enabling temperature monitoring.

[0089] In one embodiment, the external factor is pressure, which affects the filter device 20, thereby causing changes in the passband position and / or passband width. By measuring the changes in the number and / or position of longitudinal modes by the measuring device 40, corresponding information such as pressure and / or pressure changes can be obtained, thereby enabling pressure monitoring.

[0090] In one embodiment, the external factor is stress, which can affect the filter device 20, thereby causing changes in the passband position and / or passband width. By measuring the changes in the number and / or position of longitudinal modes by the measuring device 40, information such as the corresponding stress and / or stress change can be obtained, thereby enabling stress monitoring.

[0091] It should be understood that external factors are not limited to the above-mentioned situations, and may also be other factors, which are not limited here.

[0092] The beneficial effect of an optical sensor provided by this embodiment is that: a filtering device 20, a sensing device 30 and a measuring device 40 are provided, and the sensing device 30 senses environmental factors and affects the filtering device 20, so that the bandpass position and / or bandpass width of the filtering device 20 changes, thereby affecting the number and / or longitudinal mode positions of the laser output after passing through the filtering device 20. The measuring device 40 measures the changes in the number and / or longitudinal mode positions in the laser, thereby realizing the measurement and monitoring of extremely small changes in external factors, with high measurement accuracy and a wide range of applications.

[0093] See also Figure 8 Furthermore, the filtering device 20 includes a first filtering unit 201 and a second filtering unit 202 for filtering the laser light. The filtering range of the first filtering unit 201 partially overlaps with the filtering range of the second filtering unit 202. The sensing device 30 is connected to the first filtering unit 201 and / or the second filtering unit 202. The filtering described in this embodiment is frequency filtering, and the frequency range of the output laser light is the portion where the filtering range of the first filtering unit 201 and the filtering range of the second filtering unit 202 overlap (see Figure 6The sensing device 30 can affect the first filtering unit 201 or the second filtering unit 202 connected thereto, thereby affecting the position and / or range of overlap between the filtering range of the first filtering unit 201 and the filtering range of the second filtering unit 202, that is, affecting the passband position and / or passband width of the filtering device 20, and further affecting the number and / or position of longitudinal modes of the laser light output after passing through the filtering device 20.

[0094] See also Figure 1 and Figure 8 In one embodiment, the first filter unit 201 is a transmission filter unit that performs transmission filtering on the laser. The first filter unit 201 is connected to the laser light source 10, so that a portion of the laser generated by the laser light source 10 can enter the filter device 20 through the first filter unit 201; the second filter unit 202 is a transmission filter unit that performs transmission filtering on the laser. After passing through the second filter unit, the laser in the filter device 20 is partially transmitted and output.

[0095] When the laser light generated by the laser light source 10 passes through the first filter unit 201, due to the frequency domain reflectivity of the first filter unit 201, the laser light within the reflection range of the first filter unit 201 (i.e., the first reflection range L11) is filtered out and cannot pass through the first filter unit 201. However, the laser light outside the first reflection range L11 passes through the first filter unit 201 and enters the filter device 20. The laser light entering the filter device 20 continues to propagate to the second filter unit 202. Due to the frequency domain reflectivity of the second filter unit 202, the laser light within the reflection range of the second filter unit 202 (i.e., the second reflection range L21) is filtered out and cannot pass through the second filter unit 202. However, the laser light outside the second reflection range L21 passes through the second filter unit 202 and is emitted. The overlapping portion of the frequency domain outside the first reflection range L11 and the frequency domain outside the second reflection range L21 constitutes the filter range L30. The laser light output after passing through the second filter unit 202 is the laser light within the filter range L30.

[0096] It should be understood that the first filtering unit 201 can also allow part of the laser to be transmitted, while the part of the laser that cannot be transmitted will be absorbed by the first filtering unit 201; the second filtering unit 202 can also allow part of the laser to be transmitted, while the part of the laser that cannot be transmitted will be absorbed by the second filtering unit 202.

[0097] See also Figure 2In one embodiment, the first filter unit 201 is a transmission filter unit that performs transmission filtering on the laser. The reflection range of the first filter unit 201 is the first reflection range L11, and the laser outside the first reflection range L11 passes through the first filter unit 201 to enter the filter device 20 or is emitted from the filter device 20; the second filter unit 202 is a reflection filter unit that performs reflection filtering on 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 will be reflected at the second filter unit 202; the overlapping part of the frequency domain outside the first reflection range L11 and the frequency domain outside the second transmission range L22 is the filter range L30, and the laser output after passing through the filter device 20 is the laser in the filter range L30.

[0098] See also Figure 2 and Figure 9 In one embodiment, the first filter unit 201 is a transmissive filter unit, and the second filter unit 202 is a reflective filter unit. The first filter unit 201 is connected to the laser light source 10, so that the laser light from the laser light source 10 can pass through the first filter unit 201 and enter the filter device 20. The laser light entering the filter device 20 is further transmitted to the second filter unit 202 and reflected. The reflected portion of the laser light returns to the first filter unit 201 and is filtered by the first filter unit 201 before being emitted. The output laser light is the laser light within the filtering range L30.

[0099] It should be understood that the first filtering unit 201 can also allow part of the laser to be transmitted, while the part of the laser that cannot be transmitted will be 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 within this range will be absorbed by the second filtering unit 202.

[0100] See also Figure 2 、 Figures 10 and 11 In one embodiment, the first filter unit 201 is a transmission filter unit, the second filter unit 202 is a reflection filter unit, and the optical sensor further includes a first coupling unit 50. The first coupling unit 50 is connected to the first filter unit 201, and the first coupling unit 50 is connected to the laser light source 10, thereby coupling the laser light from the laser light source 10 into the filter device 20. At this time, the laser light transmitted by the first filter unit 201 can be directly emitted through the first filter unit 201, or transmitted to the first coupling unit 50 before being emitted. Figure 12The first coupling unit 50 can also be located in the filtering device 20, and the first coupling unit 50 is connected to the laser light source 10, so that the laser of the laser light source 10 is coupled into the filtering device 20. After the laser enters the filtering device 20, it is first transmitted to the second filtering unit 202 for reflection. The reflected part of the laser returns to the first filtering unit 201 and is filtered by the first filtering unit 201 before being emitted. The output laser is the laser within the filtering range L30.

[0101] See also Figure 13 In one embodiment, the first filter unit 201 is a transmissive filter unit connected to the laser light source 10, and the second filter unit 202 is a reflective filter unit. The optical sensor further includes a first output unit 60 for outputting laser light at a side end of the filter device 20. Laser light from the laser light source 10 is sequentially transmitted through the first filter unit 201, reflected by the second filter unit 202, and then emitted through the first output unit 60. The output laser light is within the filtering range L30. The first output unit 60 can also be located outside the filter device 20 and connected to the first filter unit 201, so that the laser light is sequentially transmitted through the first filter unit 201, reflected by the second filter unit 202, and transmitted through the first filter unit 201 before being emitted through the first output unit 60.

[0102] See also Figure 3 and Figure 14 In one embodiment, the first filter unit 201 is a reflective filter unit that performs reflection filtering on 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 will be reflected at the first filter unit 201; the second filter unit 202 is a reflective filter unit that performs reflection filtering on 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 will be reflected at the second filter unit 202; the overlapping part of the frequency domain outside the first transmission range L12 and the frequency domain outside the second transmission range L22 is the filter range L30, and the laser output after passing through the filter device 20 is the laser within the filter range L30.

[0103] The optical sensor also includes a first coupling unit 50 and a first output unit 60. The first coupling unit 50 is located within the filter device 20 and is connected to the laser light source 10, thereby coupling laser light from the laser light source 10 into the filter device 20. The first output unit 60 is used to output laser light at the side of the filter device 20. Laser light from the laser light source 10 enters the filter device 20 through the first coupling unit 50, is reflected by the first filter unit 201 and the second filter unit 202, and is output through the first output unit 60. The output laser light is within 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, meaning that laser light within this range is absorbed by the first filter unit 201; and the second transmission range L22 of the second filter unit 202 can also be an absorption range, meaning that laser light within this range is absorbed by the second filter unit 202.

[0104] See also Figure 15 Furthermore, the optical sensor provided in this embodiment also includes a tuning device 70 connected to the filtering device 20 for adjusting the bandpass position and bandpass width of the filtering device 20.

[0105] In one embodiment, the tuning device 70 includes a first tuning unit 701, which is connected to the first filtering unit 201 and is used to adjust the passband position and passband width of the first filtering unit 201. By adjusting the passband position of the first filtering unit 201, the passband position of the overlapping portion of the first filtering unit 201 and the second filtering unit 202 can be adjusted; by adjusting the passband width of the first filtering unit 201, the passband width of the overlapping portion of the first filtering unit 201 and the second filtering unit 202 can be adjusted.

[0106] In one embodiment, the tuning device 70 includes a second tuning unit 702, which is connected to the second filtering unit 202 and is configured to adjust the passband position and / or passband width of the second filtering unit 202. By adjusting the passband position of the second filtering unit 202, the passband position of the overlapping portion of the first filtering unit 201 and the second filtering unit 202 can be adjusted; by adjusting the passband width of the second filtering unit 202, the passband width of the overlapping portion of the first filtering unit 201 and the second filtering unit 202 can be adjusted.

[0107] See also Figure 16In one embodiment, the tuning device 70 includes a first tuning unit 701 and a second tuning unit 702. The first tuning unit 701 is connected to the first filtering unit 201, and the second tuning unit 702 is connected to the second filtering unit 202. By adjusting the passband positions of the first filtering unit 201 and the second filtering unit 202, the passband positions of the overlapping portions of the first filtering unit 201 and the second filtering unit 202 can be adjusted (see Figure 4 , L30' is the bandpass position before adjustment, L30 is the bandpass position after adjustment); by adjusting the bandpass width of the first filtering unit 201 and the second filtering unit 202, the bandpass width of the overlapping portion of the first filtering unit 201 and the second filtering unit 202 can be adjusted (see Figure 5 , L30' is the bandpass width before adjustment, and L30 is the bandpass width after adjustment. The first tuning unit 701 is connected to the first filtering unit 201, and the second tuning unit 702 is connected to the second filtering unit 202. By affecting the physical and chemical properties of the grating (including temperature, stress, pressure, etc.), the bandpass position and bandpass width can be adjusted to meet specific usage requirements.

[0108] See also Figure 17 Furthermore, the optical sensor provided in this embodiment may include a first isolation unit 80 arranged on the output path of the filtering device 20. The first isolation unit 80 is arranged between the filtering device 20 and the measuring device 40 to isolate the reverse laser, thereby protecting the optical sensor.

[0109] Furthermore, the optical sensor provided in this embodiment may also include a first circulator provided on the output path of the filtering device 20 , which can be used to output the laser on the one hand and transmit the laser back to the filtering device 20 on the other hand.

[0110] Furthermore, the first filtering unit 201 may be a high-reflection fiber Bragg grating, and the second filtering unit 202 may be a high-reflection fiber Bragg grating. Due to its frequency domain reflectivity, the high-reflection fiber Bragg grating filters the light (including laser) in the frequency domain within its reflection range.

[0111] See also Figure 24Furthermore, the measuring device 40 includes a measuring device filtering module 401 for filtering laser light, a measuring device tuning module 402 for adjusting the passband position and passband width of the measuring device filtering module 401, and a measuring device detection module 403 for detecting laser longitudinal modes. The laser light output after passing through the measuring device filtering module 401 is single longitudinal mode laser light. The measuring device tuning module 402 is connected to the measuring device filtering module 401, and the measuring device detection module 403 is located on the output path of the measuring device filtering module 401. Laser light from the filtering device 20 is filtered by the measuring device filtering module 401 and then output and transmitted to the measuring device detection module 403 for measurement. In this embodiment, the measuring device detection module 403 is used to detect whether laser light is being output. During the detection process, the single longitudinal mode laser signal detected by the measuring device detection module 403 will exhibit a cycle of appearance and disappearance. By recording the number of appearances of the single longitudinal mode laser signal, the number of longitudinal modes can be obtained.

[0112] When it is necessary to measure the laser longitudinal mode, the measurement device tuning module 402 first adjusts the bandpass position of the measurement device filter module 401 so that the bandpass position of the measurement device filter module 401 is outside the laser frequency. At this time, the measurement device detection module 403 cannot detect any laser output. The laser light from the filter device 20 enters the measurement device filter module 401, is filtered by the measurement device filter module 401, and is output and transmitted to the measurement device detection module 403. The measurement device detection module 403 detects whether there is laser output. During the detection process, the measurement device tuning module 402 adjusts the bandpass position of the measurement device filter module 401 so that the bandpass position sequentially sweeps across the laser frequency range (the scanning sequence can be from low frequency to high frequency or from high frequency to low frequency). When the laser longitudinal mode is within the bandpass range of the measurement device filter module 401, the laser light having this longitudinal mode is output to the measurement device detection module 403, and the measurement device detection module 403 detects the laser output. After the bandpass position of the filter module 401 of the measuring device sweeps through the frequency range of the laser, the detection module 403 of the measuring device records the number of times the laser is output, thereby obtaining the number of longitudinal modes.

[0113] By setting up a measuring device filter module 401, a single longitudinal mode laser can be obtained after the laser is filtered by the measuring device filter module 401. At the same time, the bandpass position of the measuring device filter module 401 is adjusted by the measuring device tuning module 402, and the frequency range of the laser can be scanned in sequence. The number of laser outputs is detected by the measuring device detection module 403, so that the number of longitudinal modes can be obtained; when external factors change, the number and / or longitudinal mode positions in the laser will change, so that the number and / or longitudinal mode positions detected by the measuring device detection module 403 will change, which can realize the measurement and monitoring of extremely small changes in external factors, with high measurement accuracy and a wide range of applications.

[0114] See also Figure 23 Furthermore, the measuring device tuning module 402 is also used to adjust the measuring device bandpass width L60 of the measuring device filter module 401, so that the bandpass width L60 of the measuring device filter module 401 can be adjusted to be narrow enough to be smaller than the width L61 between adjacent longitudinal modes in the multi-longitudinal mode laser, thereby ensuring that the laser output after passing through the measuring device filter module 401 is a single longitudinal mode laser.

[0115] See also Figure 25 In one embodiment, the measurement device filtering module 401 includes a first measurement device filtering unit 4011 and a second measurement device filtering unit 4012 for filtering laser light. The measurement device tuning module 402 is connected to the first measurement device filtering unit 4011 and / or the second measurement device filtering unit 4012, thereby adjusting the passband position and / or passband width of the first measurement device filtering unit 4011 and / or the second measurement device filtering unit 4012. The filtering range of the first measurement device filtering unit 4011 partially overlaps with the filtering range of the second measurement device filtering unit 4012. After filtering by the first measurement device filtering unit 4011 and the second measurement device filtering unit 4012, the laser light is converted into a single longitudinal mode laser and output to the measurement device detection module 403.

[0116] The adjustment method of the measurement device tuning module 402 includes at least:

[0117] Adjusting the passband position and passband width of the first filter unit 4011 or the second filter unit 4012 of the measuring device;

[0118] Adjust the passband position and passband width of the first filter unit 4011 and the second filter unit 4012 of the measuring device;

[0119] Adjust the passband position of the first filter unit 4011 of the measuring device, and adjust the passband width of the second filter unit 4012 of the measuring device;

[0120] The passband width of the first filter unit 4011 of the measuring device is adjusted, and the passband position of the second filter unit 4012 of the measuring device is adjusted.

[0121] Because the measurement device filter module 401 includes two filter units (a first measurement device filter unit 4011 and a second measurement device filter unit 4012) with partially overlapping filtering ranges, even if each filter unit has a relatively wide filtering range, by adjusting the first measurement device filter unit 4011 and / or the second measurement device filter unit 4012 via the measurement device tuning module 402, a laser with an extremely narrow linewidth can be obtained, thereby achieving single longitudinal mode filtering output. Because the filtering range requirements for each filter unit are relatively low, filter units with lower parameters and wider filtering ranges can be utilized, significantly reducing process complexity.

[0122] In one embodiment, the measuring device tuning module 402 includes a first measuring device tuning unit 4021, which is connected to the first measuring device filtering unit 4011 and is configured to adjust the passband position and / or passband width of the first measuring device filtering unit 4011. By adjusting the passband position of the first measuring device filtering unit 4011, the passband position of the overlapping portion of the first measuring device filtering unit 4011 and the second measuring device filtering unit 4012 can be adjusted; by adjusting the passband width of the first measuring device filtering unit 4011, the passband width of the overlapping portion of the first measuring device filtering unit 4011 and the second measuring device filtering unit 4012 can be adjusted.

[0123] In one embodiment, the measuring device tuning module 402 includes a measuring device second tuning unit 4022, which is connected to the measuring device second filtering unit 4012 and is configured to adjust the passband position and / or passband width of the measuring device second filtering unit 4012. By adjusting the passband position of the measuring device second filtering unit 4012, the passband position of the overlapping portion of the measuring device first filtering unit 4011 and the measuring device second filtering unit 4012 can be adjusted; by adjusting the passband width of the measuring device second filtering unit 4012, the passband width of the overlapping portion of the measuring device first filtering unit 4011 and the measuring device second filtering unit 4012 can be adjusted.

[0124] See also Figure 25In one embodiment, the measuring device tuning module 402 includes a first measuring device tuning unit 4021 and a second measuring device tuning unit 4022. The first measuring device tuning unit 4021 is connected to the first measuring device filtering unit 4011, and the second measuring device tuning unit 4022 is connected to the second measuring device filtering unit 4012. By adjusting the passband positions of the first measuring device filtering unit 4011 and the second measuring device tuning unit 4022, the passband position of the overlapping portion of the first measuring device filtering unit 4011 and the second measuring device filtering unit 4012 can be adjusted (see Figure 21 , L60' is the bandpass position before adjustment, L60 is the bandpass position after adjustment); by adjusting the bandpass width of the first filter unit 4011 of the measuring device and the second filter unit 4012 of the measuring device, the bandpass width of the overlapping portion of the first filter unit 4011 and the second filter unit 4012 of the measuring device can be adjusted (see Figure 22 , L60' is the bandpass width before adjustment, and L60 is the bandpass width after adjustment).

[0125] See also Figure 18 and Figure 25 In one embodiment, the first filtering unit 4011 of the measuring device is a transmission filtering unit that performs transmission filtering on the laser. A portion of the laser from the filtering device 20 passes through the first filtering unit 4011 of the measuring device and enters the filtering module 401 of the measuring device. The second filtering unit 4012 of the measuring device is a transmission filtering unit that performs transmission filtering on the laser. After passing through the second filtering unit, a portion of the laser in the filtering module 401 of the measuring device is transmitted, thereby being output to the detection module 403 of the measuring device.

[0126] When the laser light passes through the first filter unit 4011 of the measuring device, due to the frequency domain reflectivity of the first filter unit 4011, the laser light within the reflection range of the first filter unit 4011 (i.e., the first reflection range L41 of the measuring device) is filtered out and cannot pass through the first filter unit 4011. However, the laser light outside the first reflection range L41 of the measuring device passes through the first filter unit 4011 and enters the filter module 401 of the measuring device. The laser light entering the filter module 401 of the measuring device continues to propagate to the second filter unit 4012 of the measuring device. Due to the frequency domain reflectivity of the second filter unit 4012, the laser light within the reflection range of the second filter unit 4012 (i.e., the second reflection range L51 of the measuring device) is filtered out and cannot pass through the second filter unit 4012. However, the laser light outside the second reflection range L51 of the measuring device passes through the second filter unit 4012 and exits. The overlapping 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 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.

[0127] It should be understood that the first filter unit 4011 of the measuring device can also allow part of the laser to be transmitted, while the part of the laser that cannot be transmitted will be absorbed by the first filter unit 4011 of the measuring device; the second filter unit 4012 of the measuring device can also allow part of the laser to be transmitted, while the part of the laser that cannot be transmitted will be absorbed by the second filter unit 4012 of the measuring device.

[0128] In one embodiment, the first filter unit 4011 of the measuring device is a transmission filter unit that performs transmission filtering on the laser. The reflection range of the first filter unit 4011 of the measuring device is the first reflection range L41 of the measuring device. Laser light outside the first reflection range L41 of the measuring device passes through the first filter unit 4011 and enters the filter module 401 of the measuring device or is emitted from the filter module 401 of the measuring device. The second filter unit 4012 of the measuring device is a reflection filter unit that performs reflection filtering on the laser. The transmission range of the second filter unit 4012 of the measuring device is the second transmission range L52 of the measuring device. 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 overlapping portion 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 is the filter range L60 of the measuring device (the filter range L60 of the measuring device is less than the width between adjacent longitudinal modes in a multi-longitudinal mode laser). The laser light output after passing through the filter module 401 of the measuring device is a single longitudinal mode laser light within the filter range L60 of the measuring device.

[0129] See also Figure 19 and Figure 26 In one embodiment, the first filter unit 4011 of the measuring device is a transmissive filter unit, and the second filter unit 4012 of the measuring device is a reflective filter unit. Laser light passes through the first filter unit 4011 and enters the filter module 401 of the measuring device. The laser light that enters the filter module 401 is then transmitted to the second filter unit 4012, where it is reflected. The reflected portion of the laser light then returns to the first filter unit 4011, where it is filtered by the first filter unit 4011 before being emitted. The output laser light then falls within the filter range L60 of the measuring device.

[0130] It should be understood that the first filtering unit 4011 of the measuring device can also allow part of the laser to be transmitted, while the part of the laser that cannot be transmitted will be absorbed by the first filtering unit 4011 of the measuring device; the second transmission range L52 of the measuring device second filtering unit 4012 of the measuring device can also be an absorption range, that is, the laser within this range will be absorbed by the second filtering unit 4012 of the measuring device.

[0131] See also Figure 19 、 Figures 27 and 28 In one embodiment, the first filter unit 4011 of the measuring device is a transmission filter unit, and the second filter unit 4012 of the measuring device is a reflection filter unit. The optical sensor further includes a second coupling unit 404, which is connected to the first filter unit 4011 of the measuring device and couples the laser light into the filter module 401 of the measuring device. In this case, the laser light transmitted through the first filter unit 4011 of the measuring device can be directly emitted through the first filter unit 4011 of the measuring device, or can be transmitted to the second coupling unit 404 before being emitted. Figure 29 The second coupling unit 404 may also be located in the filter module 401 of the measuring device, and the second coupling unit couples the laser into the filter module 401 of the measuring device. After the laser enters the filter module 401 of the measuring device, it is first transmitted to the second filter unit 4012 of the measuring device and reflected. 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 before being emitted. The output laser is the laser within the filter range L60 of the measuring device.

[0132] See also Figure 19 and Figure 30In one embodiment, the first filter unit 4011 of the measuring device is a transmissive filter unit, and the second filter unit 4012 of the measuring device is a reflective filter unit. The optical sensor further includes a second output unit 405 for outputting laser light at a side end of the measuring device filter module 401. The laser light is emitted from the second output unit 405 and then transmitted to the measuring device detection module 403. The laser light is sequentially transmitted through the first filter unit 4011, reflected from the second filter unit 4012, and then emitted through the second output unit 405. The output laser light is within the measuring device's filtering range L60. The second output unit 405 can also be located outside the measuring device filter module 401 and connected to the first filter unit 4011. The laser light is then sequentially transmitted through the first filter unit 4011, reflected from the second filter unit 4012, and then transmitted through the first filter unit 4011, before being emitted through the second output unit 405 to the measuring device detection module 403.

[0133] See also Figure 20 and Figure 31 In one embodiment, the first filter unit 4011 of the measuring device is a reflective filter unit that performs reflection filtering on the laser. 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 will be reflected at the first filter unit 4011 of the measuring device. The second filter unit 4012 of the measuring device is a reflective filter unit that performs reflection filtering on 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 will be reflected at the second filter unit 4012 of the measuring device. The overlapping portion 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 is the filter range L60. The filter range L60 is smaller than the width between adjacent longitudinal modes in the multi-longitudinal mode laser. The laser light output after passing through the filter module 401 of the measuring device is the laser light within the filter range L60 of the measuring device.

[0134] The optical sensor also includes a second coupling unit 404 and a second output unit 405. The second coupling unit 404 is located within the measuring device filter module 401 and couples laser light into the measuring device filter module 401. The second output unit 405 is configured to output laser light to the measuring device detection module 403 at the side of the measuring device filter module 401. Laser light from the filter device 20 enters the measuring device filter module 401 through the second coupling unit 404, is reflected by the first measuring device filter unit 4011 and the second measuring device filter unit 4012, and is then output to the measuring device detection module 403 through the second output unit 405. The output laser light is within the measuring device filter range L60.

[0135] It should be understood that the first transmission range L42 of the measuring device of the first filtering unit 4011 of the measuring device can also be an absorption range, that is, the laser within this range will be absorbed by the first filtering unit 4011 of the measuring device; the second transmission range L52 of the measuring device of the second filtering unit 4012 of the measuring device can also be an absorption range, that is, the laser within this range will be absorbed by the second filtering unit 4012 of the measuring device.

[0136] See also Figure 32 Furthermore, the optical sensor provided in this embodiment may include a second isolation unit 406 arranged on the output path of the measuring device filter module 401, and the second isolation unit 406 is arranged between the measuring device filter module 401 and the measuring device detection module 403, and is used to isolate the reverse laser, thereby protecting the optical sensor.

[0137] Furthermore, the first filter unit 4011 of the measuring device can be a highly reflective fiber Bragg grating, and the second filter unit 4012 of the measuring device can be a highly reflective fiber Bragg grating. Due to its frequency domain reflectivity, the highly reflective fiber Bragg grating filters light (including laser light) within its frequency domain reflection range. The first tuning unit 4021 of the measuring device is connected to the first filter unit 4011 of the measuring device, and the second tuning unit 4022 of the measuring device is connected to the second filter unit 4012 of the measuring device. By influencing the physical and chemical properties of the grating (including temperature, stress, pressure, etc.), the bandpass position and bandpass width can be adjusted to meet specific usage requirements.

[0138] Furthermore, the laser light source 10, the filtering device 20, the measuring device 40 and other devices can be connected by optical fibers to realize an all-fiber optical filter with higher sensitivity, larger dynamic range, faster response speed, etc.; some devices can also be connected by optical fibers to realize a partial fiber optical filter; and light can also be transmitted through free space, which is not restricted here.

[0139] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. An optical sensor, characterized in that: include A laser light source, used for outputting laser light; A filtering device, used for filtering the laser; a sensing device, connected to the filtering device, for sensing external factors; The measuring device is arranged on the output path of the filtering device and is at least used to measure the number of longitudinal modes of the laser.

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

3. The optical sensor according to claim 2, wherein: The first filtering unit is a transmission filtering unit, which is used to connect to the laser light source and perform transmission filtering on the laser; The second filtering unit is a transmission filtering unit, configured to perform transmission filtering on the laser and output the laser.

4. The optical sensor according to claim 2, wherein: The first filtering unit is a transmission filtering unit that performs transmission filtering on the laser; The second filtering unit is a reflective filtering unit, configured to perform reflective filtering on the laser.

5. The optical sensor according to claim 4, wherein: The first filter unit is further configured to be connected to the laser light source. The laser light is sequentially transmitted through the first filter unit, reflected by the second filter unit, and then emitted through the first filter unit.

6. The optical sensor according to claim 4, wherein: The optical sensor further includes an output unit for outputting the laser light at a side end of the filtering device; The first filter unit is further configured to be connected to the laser light source. The laser light is sequentially transmitted through the first filter unit, reflected by the second filter unit, and then emitted through the output unit.

7. The optical sensor according to claim 4, wherein: The optical sensor further comprises a coupling unit for coupling the laser light from the laser light source into the filtering device; The laser is reflected by the coupling unit, the second filtering unit, and the first filtering unit in sequence before being emitted.

8. The optical sensor according to claim 2, wherein: The first filtering unit is a reflective filtering unit that performs reflective filtering on the laser; The second filtering unit is a reflective filtering unit, configured to perform reflective filtering on the laser; The optical sensor further comprises: a coupling unit, configured to couple the laser light from the laser light source into the filtering device; An output unit is used to output the laser at a side end of the filtering device.

9. The optical sensor according to claim 1, wherein: The optical sensor further comprises: A tuning device is connected to the filtering device and is used to adjust the passband position and passband width of the filtering device.

10. The optical sensor according to any one of claims 1 to 9, wherein: The measuring device includes: A measuring device filter module, used for filtering the laser light, wherein the laser light outputted after passing through the measuring device filter module is a single longitudinal mode laser light; a measuring device tuning module, connected to the measuring device filtering module, and at least used to adjust the bandpass position of the measuring device filtering module; The measuring device detection module is provided on the output path of the measuring device filter module and is used to detect the laser.

11. The optical sensor according to claim 10, wherein: The measuring device filtering module includes a first measuring device filtering unit and a second measuring device filtering unit for filtering the laser, and the measuring device tuning module is connected to the first measuring device filtering unit and / or the second measuring device filtering unit.

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