A dual-wavelength laser temperature measurement device based on optical fiber transmission signal

Abstract

A dual-wavelength laser temperature measurement device based on optical fiber transmission of optical signals, comprising: a first branch optical fiber for transmitting a first wavelength laser; a second branch optical fiber for transmitting a second wavelength laser; a third branch optical fiber for transmitting a first wavelength radiation energy of a target surface; a fourth branch optical fiber for transmitting a second wavelength radiation energy of a target surface; an optical fiber main line for aggregating the branch optical fibers and forming a unified optical fiber end face; an optical fiber combiner for connecting the optical fiber branch line and the optical fiber main line; a concave reflector for guiding the first and second wavelength laser signals and the radiation energy of the target surface; a first photothermal effect detector and a second photothermal effect detector for respectively converting the optical signals of the two wavelengths into electrical signals. The device can effectively simplify the optical system of the dual-wavelength radiation temperature measurement device, reduce the overall complexity of the device, reduce the interference of the external environment on the temperature measurement process, and improve the stability of the measurement.

Description

Technical Field

[0001] The present invention relates to the technical field of radiation temperature measurement, and in particular to a dual-wavelength laser temperature measurement device based on optical fiber transmission signals. Background Art

[0002] Dual-wavelength laser temperature measurement is a non-contact radiation temperature measurement method with broad application prospects. This method does not require the emissivity of the target surface to be measured in advance, and breaks away from the limitations of traditional radiation temperature measurement methods in obtaining the emissivity of the object surface.

[0003] The dual-wavelength laser temperature measurement device mainly includes laser emission module, optical signal transmission module, optical signal receiving module and signal processing module. Among them, the optical signal transmission module is usually composed of different numbers of optical components such as reflectors, spectroscopes and lenses. The optical components need to be precisely matched. More optical components increase the complexity of the dual-wavelength laser temperature measurement device, which brings certain challenges to the promotion and application of the temperature measurement device.

[0004] Therefore, it is necessary to simplify the modules of the device and reduce the overall complexity of the device to reduce the interference of the external environment on the temperature measurement process and further improve the stability of the measurement. Summary of the invention

[0005] The purpose of the present invention is to provide a dual-wavelength laser temperature measurement device based on optical fiber transmission signals to solve the problem of simplifying the optical signal transmission module and reduce the complexity of the device.

[0006] In order to achieve the above object, the present invention provides a dual-wavelength laser temperature measurement device based on optical fiber transmission of optical signals, which includes:

[0007] A first branch optical fiber, which is used to transmit a laser of a first wavelength;

[0008] A second branch optical fiber, which is used to transmit a second wavelength laser;

[0009] A third optical fiber, which is used to transmit radiation energy of the first wavelength to the target surface;

[0010] A fourth optical fiber, which is used to transmit radiation energy of a second wavelength to the target surface;

[0011] The optical fiber main line is used to aggregate the optical fibers and form a unified optical fiber end face;

[0012] Fiber combiner, which is used to connect the fiber branch and the fiber main;

[0013] A concave mirror reflector, which is used to collect the first and second laser signals and the radiation energy of the target surface;

[0014] A first laser emitter that generates a first laser having a first wavelength;

[0015] a second laser emitter generating a second laser having a second wavelength;

[0016] A laser modulator, used to control the frequency of the lasers emitted by the first and second laser emitters;

[0017] The first and second detection paths convert the optical signals of the two wavelengths into electrical signals respectively;

[0018] The signal amplifier takes the electrical signal and amplifies it;

[0019] The calculation circuit converts the amplified electrical signal into a temperature value through a preset program;

[0020] The numerical display shows the specific temperature value.

[0021] Among them, the core diameters of the first to fourth branch optical fibers and the optical fiber main line are 3-100 microns, and are made of a high refractive index light-guiding material, such as silica doped with a certain proportion of germanium dioxide; the core is covered by a cladding, and the cladding has a low outer diameter of 100-160 microns, and is made of a refractive index light-guiding material, such as silica doped with a certain proportion of boron oxide; the cladding is wrapped by a primary and a secondary coating layer respectively, which plays a role in protection and improving strength.

[0022] The optical fiber combiner integrates the first to fourth optical fibers and connects them to the optical fiber main line;

[0023] The reflector is a concave mirror, which reflects the laser emitted from the optical fiber main end face to the target surface and also reflects the thermal radiation light signal of the target surface to the optical fiber main end face.

[0024] Among them, the laser modulator, the first laser emitter and the second laser emitter constitute a laser emission module: the first laser emitter emits a laser with a center wavelength of 900-1200nm and a power of 1-9W; the second laser emitter emits a laser with a center wavelength of 1300-1800nm ​​and a power of 1-9W; the laser modulator controls the power supply of the laser emitter by outputting high and low level signals through a function generator to achieve the required laser frequency modulation function.

[0025] Among them, the first detection path includes a first collimating lens group, a first filter and a first photothermal effect detector: the working center wavelength range of the first filter is 900-1200nm, and the bandwidth is 3-25nm; the core component of the first photothermal effect detector is formed of photoelectric materials, which can convert optical signals into electrical signals; the filter needs to be equipped with a constant temperature auxiliary system to keep the working temperature of the filter constant.

[0026] Among them, the second detection path includes a second collimating lens group, a second filter and a second photothermal effect detector: the working center wavelength range of the second filter is 1300-1800nm, and the bandwidth is 5-50nm; the core component of the second photothermal effect detector is formed of photoelectric materials, which can convert optical signals into electrical signals; the filter needs to be equipped with a constant temperature auxiliary system to keep the working temperature of the filter constant.

[0027] The amplifier includes a low noise amplifier and a phase-locked amplifier, the calculation circuit converts the received electrical signal into a temperature value through a preset calculation program, and the display is used to display the target surface temperature value obtained by measurement.

[0028] It can be seen from the technical solution of the dual-wavelength laser temperature measurement device based on optical fiber transmission of optical signals of the present invention that the core components of the system of the present invention include: a laser emission module, an optical signal transmission module, a first detection path and a second detection path. Through the coordinated work of the laser emission module and the first and second detection path systems, the surface temperature can be accurately measured under the condition that the emissivity of the surface of the object is unknown; the optical signal transmission module is used to transmit the lasers generated by the first and second laser generators and the radiation energy emitted by the target surface.

[0029] The present invention provides a dual-wavelength laser temperature measuring device based on optical fiber transmission of optical signals. The optical fiber is used to transmit signals such as infrared laser and target surface radiation energy, so that the optical signal transmission module of the dual-wavelength radiation temperature measuring device is effectively simplified, the overall complexity of the device is reduced, the interference of the external environment on the temperature measurement process is reduced, and the stability of the measurement is further improved.

[0030] Additional aspects and advantages of the present invention will be given in part in the following description, which will become obvious from the following description, or may be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0032] Figure 1 The figure is a schematic diagram of a dual-wavelength laser temperature measurement device based on optical fiber transmission of optical signals according to an embodiment of the present invention. DETAILED DESCRIPTION

[0033] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be interpreted as limiting the present invention.

[0034] It will be understood by those skilled in the art that, unless expressly stated, the singular forms "one", "said", and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present invention refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. It should be understood that when we refer to an element as being "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or there may be intermediate elements. In addition, the "connection" or "coupling" used herein may include wireless connection or coupling. The term "and / or" used herein includes any unit and all combinations of one or more associated listed items.

[0035] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those generally understood by those skilled in the art in the art to which the present invention belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless defined as herein.

[0036] To facilitate understanding of the embodiments of the present invention, further explanation will be given below using specific embodiments as examples in conjunction with the accompanying drawings.

[0037] Example

[0038] Figure 1 FIG. 1 is a schematic diagram of a dual-wavelength laser temperature measurement device based on optical fiber transmission signals according to an embodiment of the present invention. Figure 1 As shown, the temperature measuring device includes: a laser modulator 1, which is used to output high and low level signals of different frequencies; a first laser emitter 2, which generates a first laser with a first wavelength; a second laser emitter 3, which generates a second laser with a second wavelength; the laser modulator 1 is connected with the first laser emitter 2 and the second laser emitter 3 to form a laser emission module, and the high and low level signals output by the laser modulator 1 are used to control the first laser emitter 2 or the second laser emitter 3 to generate laser of the required frequency. The laser light source system is not limited to the laser modulator 1, the first laser emitter 2 and the second laser emitter 3, and may also include other optical and electrical components.

[0039] Among them, the laser modulator 1, the first laser emitter 2 and the second laser emitter 3 cooperate with each other as a laser emission module: the first laser emitter 2 emits a laser with a center wavelength of 900-1200nm and a power of 1-9W; the second laser emitter 3 emits a laser with a center wavelength of 1300nm-1800nm ​​and a power of 1-9W; the laser modulator 1 directly controls the power supply of the first laser emitter 2 and the second laser emitter 3 by outputting high and low level signals through a function generator, thereby realizing the required laser frequency modulation function.

[0040] Under the control of the laser modulator 1, the first laser emitted by the first laser generator 2 enters the first branch fiber 4, enters the fiber bus 6 after passing through the fiber combiner 5, and reaches the target surface after passing through the concave reflector 7; the second laser emitted by the second laser generator 3 enters the second branch fiber 8, enters the fiber bus 6 after passing through the fiber combiner 5, and reaches the target surface after passing through the concave reflector 7; the target surface generates a temperature rise ΔT under the heating of the laser, and the radiation energy emitted by the target surface within a certain solid angle is reflected by the concave reflector 7, enters the fiber bus 6, and enters the third branch fiber 9 and the fourth branch fiber 10 after passing through the fiber combiner 5; the radiation signal of the target surface is emitted from the third branch fiber 8. After the optical fiber 9, the radiation signal of the target surface becomes a radiation beam with a first wavelength as the central wavelength under the action of the first collimating lens group 11 and the first filter 12, and then reaches the first photothermal effect detector 13; after the radiation signal of the target surface exits the fourth optical fiber 10, it becomes a radiation beam with a second wavelength as the central wavelength under the action of the second collimating lens group 14 and the second filter 15, and then reaches the second photothermal effect detector 16; the first photothermal effect detector 13 and the second photothermal effect detector 16 input the obtained electrical signal into the amplifier 17, and the calculation circuit 18 converts the signal from the amplifier 17 into a corresponding temperature value and displays it on the display instrument 19. Among them, the amplifier includes a low noise amplifier and a phase-locked amplifier, and the calculation circuit converts the received electrical signal into a temperature value according to a preset calculation program.

[0041] The first to fourth optical fibers (4, 8, 9, 10), the optical fiber combiner 5, the optical fiber bus 6 and the concave reflector group 7 cooperate with each other as an optical signal transmission module for transmitting the lasers generated by the first and second laser emitters (2, 3) and the radiation energy emitted by the target surface. The optical signal transmission module is not limited to the above components and can also include or be replaced by other optical elements; the first collimating lens group 11, the first filter 12 and the first photothermal effect detector 13 cooperate with each other as a first detection path, and the working center wavelength range of the first filter 12 is preferably 900-1200nm, and the bandwidth is preferably 3-25nm; the second collimating lens group 14, the second filter 15 and the second photothermal effect detector 16 cooperate with each other as a second detection path, and the working center wavelength range of the second filter 15 is preferably 1300-1800nm, and the bandwidth is preferably 5-50nm; the filters in the first detection path and the second detection path are required to be equipped with a constant temperature auxiliary system to keep the working temperature of the filters constant.

[0042] The specific process of using the measuring device of the present invention to perform radiation temperature measurement includes the following steps:

[0043] First, the laser modulator 1 outputs high and low level signals to directly control the power supply of the laser transmitter. The first laser transmitter 2 emits a laser beam with a wavelength of λ1 (980nm). The laser beam enters the first optical fiber 4 for transmission, passes through the optical fiber combiner 5, enters the optical fiber bus 6, and is reflected to the target surface by the concave reflector 7 after exiting the end face of the optical fiber bus 6, causing it to generate a temperature rise of ΔT1. The radiation energy emitted by the target surface within a certain solid angle is reflected to the optical fiber bus 6 by the objective lens concave reflector 7 and transmitted, and reaches the fourth optical fiber 10 through the optical fiber combiner 5. The radiation beam with a central wavelength of λ2 (1550nm) passes through the second collimating lens group 14 and the second filter 15, and then reaches the second photothermal effect detector 16, generating a photocurrent I under the action of the photothermal effect. p (λ2).

[0044] Similarly, the laser modulator 1 outputs high and low level signals to directly control the power supply of the laser. The second laser emitter 3 emits a laser beam with a wavelength of λ2 (1550nm). The laser beam enters the second optical fiber 8 for transmission, passes through the optical fiber combiner 5, enters the optical fiber bus 6, and is reflected to the target surface by the concave reflector 7 after exiting the end face of the optical fiber bus 6, causing it to generate a temperature rise of ΔT2. The radiation energy emitted by the target surface within a certain solid angle is reflected to the optical fiber bus by the objective lens concave reflector 7 and transmitted, and reaches the third optical fiber 9 after passing through the optical fiber combiner 5. The radiation beam with a central wavelength of λ1 (980nm) passes through the first collimating lens group 11 and the first filter 12, and then reaches the second photothermal effect detector 13, generating a photocurrent I under the action of the photothermal effect. p (λ1).

[0045] I p (λ2) and I p (λ1) can be separated into variables to obtain a proportionality coefficient consisting of the product of the surface emissivity of the target surface at two wavelengths of λ1 and λ2. p (λ2) and I p (λ1) can eliminate the influence of emissivity. p (λ2) and I p The ratio of (λ1) is only related to the instrument constant, wavelength, second radiation constant and target surface temperature, and the instrument constant can be accurately determined by laboratory calibration. p (λ2) and I p The ratio of (λ1) can be converted to the surface temperature of the target to be measured. The algorithm is programmed and preset in the calculation circuit in advance, and the electrical signal can be converted into a temperature value during the measurement process.

[0046] The present invention provides a dual-wavelength laser temperature measurement device based on optical fiber transmission of optical signals. Through the coordinated work of a laser emission module, an optical signal transmission module and first and second detection path systems, the surface temperature can be accurately measured under the condition that the surface emissivity of an object is unknown. The lasers generated by the first and second laser generators and the radiation energy emitted by the target surface are transmitted through the optical fiber, which effectively simplifies the optical signal transmission module, reduces the overall complexity of the device, reduces the interference of the external environment on the temperature measurement process, and further improves the stability of the measurement.

[0047] Those skilled in the art should understand that the above-mentioned application types are only examples, and other existing or future application types, if applicable to the embodiments of the present invention, should also be included in the protection scope of the present invention and are included here by reference.

[0048] Those skilled in the art should understand that Figure 1 The number of various components shown for simplicity may be smaller than that in an actual system, but such omission is undoubtedly based on the premise that it will not affect the clear and sufficient disclosure of the embodiments of the invention.

[0049] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A dual-wavelength laser temperature measurement device based on optical fiber transmission signal, comprising: A first laser emitter that generates a first laser having a first wavelength; a second laser emitter generating a second laser having a second wavelength; A laser modulator, used to control the frequency of the lasers emitted by the first and second laser emitters, the laser modulator directly controls the power supply of the first laser emitter and the second laser emitter by outputting high and low level signals through a function generator, thereby realizing the required laser frequency modulation function; A first branch optical fiber, used for transmitting a laser of a first wavelength; A second branch optical fiber is used to transmit a second wavelength laser; The third optical fiber is used to transmit the radiation energy of the first wavelength generated by the target surface; The fourth optical fiber is used to transmit the second wavelength radiation energy generated by the target surface; Optical fiber bus, used to aggregate the optical fibers and form a unified optical fiber end face; The optical fiber combiner is used to connect the first to fourth optical fibers and the optical fiber bus; the characteristics are: A concave mirror reflector is used to guide the first and second laser signals and the radiation energy of the target surface; the concave mirror reflector reflects the laser emitted from the end face of the optical fiber main line to the target surface and also reflects the thermal radiation light signal of the target surface to the end face of the optical fiber main line; A detection path, which converts the optical signal into an electrical signal, wherein the detection path includes a collimating lens group, a filter, and a photothermal effect detector; Under the control of the laser modulator, the first laser emitted by the first laser generator enters the first branch fiber, enters the fiber bus after passing through the fiber combiner, and reaches the target surface after passing through the concave reflector; the second laser emitted by the second laser generator enters the second branch fiber, enters the fiber bus after passing through the fiber combiner, and reaches the target surface after passing through the concave reflector; the target surface generates a temperature rise ΔT under the heating of the laser, and the radiation energy emitted by the target surface within a certain solid angle enters the fiber bus after being reflected by the concave reflector, and enters the third branch fiber and the fourth branch fiber after passing through the fiber combiner; after the radiation signal of the target surface exits the third branch fiber, it becomes a radiation beam with a central wavelength of the first wavelength under the action of the first collimating lens group and the first filter, and then reaches the first photothermal effect detector; After the radiation signal exits the fourth optical fiber, it becomes a radiation beam with a central wavelength of the second wavelength under the action of the second collimating lens group and the second filter, and then reaches the second photothermal effect detector; the first to fourth optical fibers, the optical fiber combiner, the optical fiber bus and the concave reflector group cooperate with each other as an optical signal transmission module, which is used to transmit the laser generated by the first and second laser transmitters and the radiation energy emitted by the target surface; the first photothermal effect detector and the second photothermal effect detector input the obtained electrical signal into the amplifier, and the calculation circuit converts the signal from the amplifier into a corresponding temperature value and displays it on the display instrument; wherein, the amplifier includes a low-noise amplifier and a phase-locked amplifier, and the calculation circuit converts the received electrical signal into a temperature value according to a pre-set calculation program.

2. The device according to claim 1, characterized in that The core diameters of the first to fourth branch optical fibers and the optical fiber main circuit are 3-100 microns and are made of light-guiding materials with high refractive index.

3. The device according to claim 1, characterized in that The optical fiber combiner integrates the first to fourth branch optical fibers and connects them to the optical fiber bus.

4. The device according to claim 1, characterized in that The first laser emitter emits a laser with a central wavelength of 900-1200 nm and a power of 1-9W; the second laser emitter emits a laser with a central wavelength of 1300-1800 nm and a power of 1-9W.

5. The device according to claim 4, characterized in that The working center wavelength range of the filter is 1300-1800 nm, and the bandwidth is 5-50 nm; the photothermal effect detector can convert the optical signal into an electrical signal.

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