Optical fiber temperature measurement device and temperature measurement method based on solid-state quantum system

Abstract

The present invention discloses an optical fiber temperature measurement device and a temperature measurement method based on a solid-state quantum system. A non-polarization beam splitter is arranged on the exit optical path of a semiconductor continuous laser, and the exit optical path of the laser is divided into an orthogonal excitation optical path and an adjustment optical path; a first reflector is arranged on the excitation optical path of the non-polarization beam splitter, an aperture and a dichroic mirror are arranged in turn in the reflected light direction of the first reflector, an optical power meter and a five-dimensional optical fiber coupling mirror 1 are arranged in the exit direction of the dichroic mirror, and a multimode optical fiber probe is connected to the end of the five-dimensional optical fiber coupling mirror 1; a high-pass filter and a five-dimensional optical fiber coupling mirror 2 are arranged along the reflection direction of the multimode optical fiber probe and after the dichroic mirror; a multimode optical fiber connects the five-dimensional optical fiber coupling mirror 2 to a spectrum analyzer; a second reflector is arranged on the adjustment optical path of the non-polarization beam splitter, and an attenuation plate and a five-dimensional optical fiber coupling mirror 3 are arranged in the reflection direction of the second reflector. The present invention can improve the accuracy of the fluorescence signal and reduce the background scattering noise.

Description

Technical Field

[0001] The present invention relates to the field of high-precision temperature measurement, and in particular to an optical fiber temperature measurement device and a temperature measurement method based on a solid-state quantum system. Background Art

[0002] Temperature is one of the most important physical concepts. Whether in the process of chemical reactions or cell biochemical reactions, all energy exchanges and releases are accompanied by temperature changes. Temperature changes caused by biochemical reactions have a considerable impact on the objects of interest, whether in the chemical industry or in life sciences. For organisms, gene expression, protein stability, enzyme-ligand interactions, and enzyme activation are all affected by temperature. In small physical changes or biochemical reactions, such as low concentrations of reactants in a solution or a small amount of solid dissolved in a large amount of solvent, the hydration heat generated by the dissolution or the thermal effect of the reaction quickly tends to equilibrium under the conduction dilution of the solvent. By measuring these small thermal changes, we can understand the thermal effect of chemical reactions, which reflects the changes in energy during chemical reactions and is of great significance for us to monitor the process of related reactions.

[0003] Traditional temperature measurement methods such as thermal imaging and thermal radiation have low measurement accuracy and slow response time, making it difficult to measure tiny temperature changes in biochemical reactions. Recently, quantum precision measurement technology based on solid-state quantum spin systems can achieve high-precision measurement of temperature signals. The nitrogen-vacancy center (NV) in diamond is a stable luminescent defect. This solid-state single spin system has the advantages of easy initialization and readout, controllability, and long coherence time. It has the advantages of high precision and fast response time when used for physical field measurements such as temperature. When combined with fiber optic sensing technology, it can even achieve non-invasive and accurate measurement of organisms, etc., and has broad prospects in the field of temperature measurement.

[0004] In the fiber optic temperature measurement technology, when the laser enters the inside of the optical fiber, the optical fiber itself will also interact with the laser, generating elastic scattering (Rayleigh scattering) and inelastic scattering (Stokes scattering, anti-Stokes scattering), etc. When using fluorescence spectroscopy to measure temperature, the above-mentioned inelastic scattered light usually returns to the collection element such as the spectrometer or light detector along with the fluorescence signal, interfering with the real fluorescence spectrum signal. Usually, the fluorescence signal and the scattered background light signal are associated, and the reference noise measured in general is mainly the thermal noise of the system in the absence of incident light (such as a darkroom environment). Therefore, when the detector collects the fluorescence signal, it is inevitable to collect the scattered background light signal. If the wavelength of the inelastic scattered light is close to the target fluorescence signal to be measured, it will cause great interference and affect the collection of the real fluorescence signal. Therefore, in the fluorescence spectrum temperature measurement technology, there is an urgent need for a measurement method that can separate the fluorescence signal from the scattered background light signal, so as to improve the accuracy of signal measurement and reduce the noise caused by the scattered background light. Summary of the invention

[0005] The purpose of the present invention is to provide an optical fiber temperature measurement device and a temperature measurement method based on a solid-state quantum system, which can separate the fluorescence signal from the background scattered light signal, while improving the accuracy of signal measurement and reducing the noise caused by the scattered background light, and is easy to install and maintain.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] An optical fiber temperature measurement device based on a solid-state quantum system, comprising a semiconductor continuous laser, a non-polarization beam splitter, a first reflector, an aperture, a dichroic mirror, an optical power meter, a five-dimensional optical fiber coupling mirror 1, a multimode optical fiber probe, a high-pass filter, a five-dimensional optical fiber coupling mirror 2, a multimode optical fiber, a spectrum analyzer, a second reflector, an attenuation plate and a five-dimensional optical fiber coupling mirror 3;

[0008] The non-polarization beam splitter is arranged on the output light path of the semiconductor continuous laser, and divides the output light path of the semiconductor continuous laser into an orthogonal excitation light path and an adjustment light path; the first reflector is arranged on the excitation light path of the non-polarization beam splitter, the aperture and the dichroic mirror are arranged in sequence in the reflected light direction of the first reflector, the optical power meter and the five-dimensional fiber coupling mirror 1 are arranged in the output direction of the dichroic mirror, and the multimode fiber probe is connected to the end of the five-dimensional fiber coupling mirror 1; the high-pass filter and the five-dimensional fiber coupling mirror 2 are arranged along the reflection direction of the multimode fiber probe and are located after the dichroic mirror; the multimode optical fiber connects the five-dimensional fiber coupling mirror 2 to the spectrum analyzer; the second reflector is arranged on the adjustment light path of the non-polarization beam splitter, and the attenuation plate and the five-dimensional fiber coupling mirror 3 are arranged in the reflection direction of the second reflector.

[0009] Furthermore, the multimode optical fiber probe is a diamond probe containing NV color centers.

[0010] Furthermore, the operating wavelength of the semiconductor continuous laser is 532 nm, the output power is 0.1-100 mW, and the output spot diameter is 2 mm.

[0011] Furthermore, the non-polarization beam splitter has an operating wavelength of 400-700 nm, a beam splitting ratio of 50:50, and a size of 10 mm.

[0012] Furthermore, the iris is a continuously variable iris adjusted by a lever, and the maximum aperture is 15 mm.

[0013] Furthermore, the dichroic mirror is a long-wave pass dichroic mirror with a starting wavelength of 550 nm; the operating wavelength of the optical power meter is 200-1100 nm, and the receiving power range is 50 nW-50 mW.

[0014] Furthermore, the specifications of the five-dimensional fiber coupling mirror 1, the five-dimensional fiber coupling mirror 2 and the five-dimensional fiber coupling mirror 3 are exactly the same, with an anti-reflection range of 400-650 nm, a light aperture of 5 mm, a numerical aperture of 0.5, and a focal length of 6.67 mm.

[0015] Furthermore, the cut-off wavelength of the high-pass filter is 550 nm, and the transmission wavelength is 560-1100 nm; the attenuation plate is a continuously variable metal film neutral density filter coated with a 350-700 nm anti-reflection film.

[0016] Furthermore, the multimode optical fibers in the multimode optical fiber and the multimode optical fiber probe are selected to have an operating wavelength of 400-2200 nm, a core diameter of 200 μm, and a numerical aperture of 0.22.

[0017] A temperature measurement method of an optical fiber temperature measurement device based on a solid-state quantum system comprises the following steps:

[0018] Step 1: The semiconductor continuous laser emits laser light, which is divided into orthogonal excitation light and adjustment light through the non-polarization beam splitter; the aperture is opened, and the excitation light passes through the first reflector, the aperture, and the dichroic mirror in sequence to enter the five-dimensional fiber coupling mirror 1, and the excitation light is coupled with the fluorescent medium at the end of the multimode fiber probe; the five-dimensional fiber coupling mirror 1 is adjusted so that the returned fluorescence signal and the background scattered light signal inside the optical fiber enter the optical power meter along the outgoing light path, and the collected power at this time is recorded as P 0; Close the aperture, remove the multimode fiber probe at the end of the five-dimensional fiber coupling mirror one, and connect the five-dimensional fiber coupling mirror three at the end of the adjustment light path to the five-dimensional fiber coupling mirror one through an additional multimode optical fiber, so that the adjustment light enters the optical power meter, and the collection power at this time is recorded as P 1 ; Adjust the attenuation plate so that P 1 =P 0 ;

[0019] Step 2: Recall the five-dimensional fiber coupling mirror 1 so that the outgoing light path coincides with the original incident light path, and the regulated light passes through the dichroic mirror, the high-pass filter, the five-dimensional fiber coupling mirror 2 and the multimode optical fiber along the outgoing light path, and enters the spectrum analyzer, and the spectrum signal collected at this time is recorded as a signal without fluorescence background; the multimode optical fiber connecting the five-dimensional fiber coupling mirror 3 and the five-dimensional fiber coupling mirror 1 is disconnected;

[0020] Step three: placing the multimode fiber probe in a temperature control device, adjusting the temperature control device to change the temperature of the fluorescent medium in the multimode fiber probe; opening the aperture, and the excitation light passes through the first reflector, the aperture, and the dichroic mirror and then enters the five-dimensional fiber coupling mirror one, the excitation light is coupled with the fluorescent medium at the end of the multimode fiber probe, and the returned fluorescence signal and scattered light pass through the dichroic mirror, the high-pass filter, the five-dimensional fiber coupling mirror two and the multimode optical fiber, and enter the spectrum analyzer, and the spectrum signal collected at this time is recorded as a test signal containing background light; subtracting the non-fluorescent background signal obtained in step two from the test signal containing background light to obtain a low-noise, real fluorescence spectrum; fitting the real spectrum signal with an exponential function and a Lorentz function through the spectrum analyzer to obtain the temperature coefficient of the fluorescence spectrum frequency shift and related expressions;

[0021] Step 4: placing the multimode fiber probe near the sample to be tested, opening the aperture, and the excitation light enters the first five-dimensional fiber coupling mirror after passing through the first reflector, the aperture, and the dichroic mirror, and the excitation light is coupled with the fluorescent medium at the end of the multimode fiber probe, and the returned fluorescence signal and scattered light pass through the dichroic mirror, the high-pass filter, the five-dimensional fiber coupling mirror 2 and the multimode optical fiber, and enter the spectrum analyzer, and the spectrum signal collected at this time is recorded as the fluorescence signal containing the background light;

[0022] Step 5: Subtract the fluorescence signal containing background light obtained in step 4 from the non-fluorescent background signal obtained in step 2 to obtain a low-noise, true fluorescence spectrum of the test sample; obtain the frequency shift of the fluorescence signal through data processing of the spectrum analyzer, and combine it with the relevant expression of the fluorescence spectrum frequency shift obtained in step 3 to obtain the temperature of the sample to be tested at different times.

[0023] The beneficial effects of the present invention are as follows:

[0024] In order to separate the fluorescence signal from the background scattered light signal in the fluorescence spectroscopy temperature measurement, the present invention proposes a dual light path setting in which an excitation light path and an adjustment light path coexist. The background scattered light signal generated by the inside of the optical fiber during the excitation process is corrected by adjusting the light path, thereby realizing the separation of the background scattered light from the overall fluorescence signal, thereby improving the accuracy of the fluorescence signal and reducing the accompanying background scattering noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities may be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0026] The flowcharts shown in the accompanying drawings are only exemplary and do not necessarily include all the contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps can be decomposed, and some operations / steps can be combined or partially combined, so the actual execution order may change according to actual conditions.

[0027] Figure 1 It is a structural schematic diagram of the optical fiber temperature measuring device of the present invention.

[0028] Figure 2 It is a schematic flow chart of the temperature measurement method of the present invention.

[0029] Figure 3 Schematic diagram of the diamond multimode optical fiber probe in Example 1.

[0030] Figure 4 It is a curve diagram showing the change of the central peak position of the fluorescence spectrum with temperature during the temperature coefficient correction process of Example 1.

[0031] Figure 5 It is a scatter plot of the temperature change over time during the process of dissolving a trace amount of NaOH obtained in Example 1 in water.

[0032] Figure 1 In the figure, 1 is a semiconductor continuous laser, 2 is a non-polarization beam splitter, 3 is a first reflector, 4 is an aperture, 5 is a dichroic mirror, 6 is an optical power meter, 7 is a five-dimensional fiber coupling mirror 1, 8 is a multimode fiber probe, 9 is a high-pass filter, 10 is a five-dimensional fiber coupling mirror 2, 11 is a multimode optical fiber, 12 is a spectrum analyzer, 13 is a second reflector, 14 is an attenuator, and 15 is a five-dimensional fiber coupling mirror 3. DETAILED DESCRIPTION

[0033] The terms used in the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The singular forms of "a", "said" and "the" used in the present invention and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0034] It should be understood that although the terms first, second, third, etc. may be used in the present invention to describe various information, these information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present invention, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0035] like Figure 1 As shown, the fiber optic temperature measuring device based on the solid-state quantum system of the present invention includes a semiconductor continuous laser 1, a non-polarization beam splitter 2, a first reflector 3, an aperture 4, a dichroic mirror 5, an optical power meter 6, a five-dimensional fiber coupling mirror 1 7, a multimode fiber probe 8, a high-pass filter 9, a five-dimensional fiber coupling mirror 2 10, a multimode optical fiber 11, a spectrum analyzer 12, a second reflector 13, an attenuation plate 14 and a five-dimensional fiber coupling mirror 3 15.

[0036] Among them, the non-polarization beam splitter 2 is arranged on the output light path of the semiconductor continuous laser 1, and the output light path of the semiconductor continuous laser 1 is divided into an orthogonal excitation light path and an adjustment light path. The first reflector 3 is arranged on the excitation light path of the non-polarization beam splitter 2, and the aperture 4 and the dichroic mirror 5 are arranged along the reflected light direction of the first reflector 3. The optical power meter 6 and the five-dimensional fiber coupling mirror 1 7 are arranged in sequence in the output direction of the dichroic mirror 5. The end of the five-dimensional fiber coupling mirror 1 7 is connected to the multimode fiber probe 8, and along the reflection direction of the multimode fiber probe 8, a high-pass filter 9 and a five-dimensional fiber coupling mirror 2 10 are arranged in sequence after the dichroic mirror 5. The end of the five-dimensional fiber coupling mirror 2 10 is connected to the spectrum analyzer 12 through a multimode optical fiber. The second reflector 13 is arranged on the adjustment light path of the non-polarization beam splitter 2, and the attenuation plate 14 and the five-dimensional fiber coupling mirror 3 15 are arranged in sequence in the reflection direction of the second reflector 13.

[0037] The multimode optical fiber probe 8 is preferably a diamond probe containing NV color centers, but other probes may also be used.

[0038] like Figure 2 As shown, the method for measuring temperature using the optical fiber temperature measuring device based on the solid-state quantum system of the present invention comprises the following steps:

[0039] Step 1: Background scattered light correction:

[0040] A semiconductor continuous laser 1 emits laser light, which is divided into orthogonal excitation light and adjustment light through a non-polarization beam splitter 2; the aperture 4 is opened, and the excitation light passes through the first reflector 3, the aperture 4, and the dichroic mirror 5 in sequence to enter the five-dimensional fiber coupling mirror 7, and the excitation light is coupled with the fluorescent medium at the end of the multimode fiber probe 8. The five-dimensional fiber coupling mirror 7 is adjusted so that the returned fluorescent signal and the background scattered light signal inside the optical fiber enter the optical power meter 6 along the outgoing light path, and the collected power at this time is recorded as P 0 Close the aperture 4, remove the multimode fiber probe 8 at the end of the five-dimensional fiber coupling mirror 7, and connect the five-dimensional fiber coupling mirror 15 at the end of the adjustment light path to the five-dimensional fiber coupling mirror 7 through an additional multimode optical fiber, so that the adjustment light enters the optical power meter 6, and the collected power at this time is recorded as P 1 ; Adjust the attenuation plate 14 so that P 1 =P 0 ;

[0041] Step 2: Baseline signal collection:

[0042] The five-dimensional fiber coupling mirror 1 7 is adjusted back to make the outgoing light path coincide with the original incident light path, so that the adjusted light passes through the dichroic mirror 5, the high-pass filter 9, the five-dimensional fiber coupling mirror 2 10 and the multimode optical fiber 11 along the outgoing light path and enters the spectrum analyzer 12, and the spectrum signal collected at this time is recorded as a signal without fluorescence background; the multimode optical fiber connecting the five-dimensional fiber coupling mirror 3 15 and the five-dimensional fiber coupling mirror 1 7 is disconnected.

[0043] Step 3: Temperature coefficient correction:

[0044] The multimode fiber probe 8 is placed in a temperature control device, and the temperature control device is adjusted to change the temperature of the fluorescent medium in the multimode fiber probe 8; the aperture 4 is opened, and the excitation light passes through the first reflector 3, the aperture 4, and the dichroic mirror 5 and then enters the five-dimensional fiber coupling mirror 1 7, and the excitation light is coupled with the fluorescent medium at the end of the multimode fiber probe 8, and the returned fluorescence signal and scattered light pass through the dichroic mirror 5, the high-pass filter 9, the five-dimensional fiber coupling mirror 2 10 and the multimode optical fiber 11, and enter the spectrum analyzer 12, and the spectrum signal collected at this time is recorded as a test signal containing background light; the non-fluorescent background signal obtained in step 2 is subtracted from the test signal containing background light to obtain a low-noise, real fluorescence spectrum; the real spectrum signal is fitted with an exponential function and a Lorentz function through the spectrum analyzer 12 to obtain the temperature coefficient of the fluorescence spectrum frequency shift and related expressions;

[0045] Step 4: Sample testing:

[0046] The multimode fiber probe 8 is placed near the sample to be tested, and the aperture 4 is opened. The excitation light passes through the first reflector 3, the aperture 4, and the dichroic mirror 5 and then enters the five-dimensional fiber coupling mirror 1 7. The excitation light is coupled with the fluorescent medium at the end of the multimode fiber probe 8. The returned fluorescence signal and the scattered light pass through the dichroic mirror 5, the high-pass filter 9, the five-dimensional fiber coupling mirror 2 10 and the multimode optical fiber 11 along the outgoing light path and enter the spectrum analyzer 12. The spectrum signal collected at this time is recorded as the fluorescence signal containing the background light.

[0047] Step 5: Signal processing:

[0048] The fluorescence signal containing background light obtained in step 4 is subtracted from the non-fluorescent background signal obtained in step 2 to obtain a low-noise, true fluorescence spectrum of the test sample. The frequency shift of the fluorescence signal is obtained by data processing of the spectrum analyzer, and combined with the temperature coefficient and expression of the fluorescence spectrum frequency shift obtained in step 3, the temperature of the sample to be tested at different times can be obtained.

[0049] The multimode optical fiber connecting the five-dimensional optical fiber coupling mirror three 15 and the five-dimensional optical fiber coupling mirror one 7 is a multimode optical fiber of the same specification and batch as the multimode optical fiber in the multimode optical fiber probe 8.

[0050] Two specific embodiments are given below, in which the optical fiber temperature measuring device of the present invention is used to test two different samples, thereby verifying the effect of the temperature measuring device and method of the present invention.

[0051] In this embodiment, the specific parameters of each device selected are as follows:

[0052] The operating wavelength of the semiconductor continuous laser 1 is 532 nm, the output power is 0.1-100 mW, and the output spot diameter is 2 mm;

[0053] The working wavelength of the non-polarizing beam splitter 2 is visible light (400-700 nm), the beam splitting ratio is 50:50, and the size is 10 mm;

[0054] Aperture 4 is a continuously variable iris adjusted by a lever, with a maximum aperture of 15 mm;

[0055] The dichroic mirror 5 is a long-wave pass dichroic mirror with a starting wavelength of 550 nm (the long-wave pass dichroic mirror has high reflectivity for light shorter than the starting wavelength and high transmittance for light higher than the starting wavelength);

[0056] The working wavelength of the optical power meter 6 is 200-1100 nm, and the receiving power range is 50 nW-50 mW;

[0057] The specifications of the five-dimensional fiber coupling mirror 1 7, the five-dimensional fiber coupling mirror 2 10 and the five-dimensional fiber coupling mirror 3 15 are exactly the same, with an anti-reflection range of 400-650 nm, a light aperture of 5 mm, a numerical aperture of 0.5, and a focal length of 6.67 mm;

[0058] The cut-off wavelength of the high-pass filter 9 is 550 nm, and the transmission wavelength is 560-1100 nm.

[0059] The attenuation plate 14 is a continuously variable metal film neutral density filter coated with a 350-700 nm anti-reflection film.

[0060] The multimode optical fibers in the multimode optical fiber 11 and the multimode optical fiber probe 8 are both selected to have an operating wavelength of 400-2200 nm, a core diameter of 200 μm, and a numerical aperture of 0.22.

[0061] Preparation of multimode fiber probe 8: Use a fiber optic cutter to cut the multimode optical fiber to form the optical fiber end face, and carefully peel off the optical fiber cladding and coating layer on the periphery of the multimode optical fiber to make the final multimode optical fiber end face smooth and flat; select micron-sized diamond particles (NV color center concentration is about 1000 ppm, size is about 300μm) prepared by high temperature and high pressure method, mix the micron-sized diamond particles into a large amount of deionized water, ultrasonically disperse for 20 minutes, and then place on a glass slide to dry. After waiting for drying, mix the micron-sized diamond particles with a small amount of UV ultraviolet curing glue, and place the micron-sized diamond particles on the end face of the multimode optical fiber through a precision translation stage under a high-power microscope or CCD. After the bonding is relatively firm, place it under a UV lamp for curing for 30 minutes, so that the micron-sized diamond particles are firmly fixed on the end face of the optical fiber. The results are as follows: Figure 3 shown.

[0062] In this embodiment, the method for measuring the temperature of a trace amount of NaOH dissolved in water using an optical fiber temperature measuring device specifically includes the following steps:

[0063] S1: Correction of the intensity of background scattered light signal: The semiconductor continuous laser 1 emits a continuous laser with a wavelength of 532 nm, and the initial output light power is set to 3 mW. The laser is divided into excitation light and adjustment light after passing through the non-polarization beam splitter 2. Open the aperture 4, and the excitation light passes through the first reflector 3, the aperture 4, and the dichroic mirror 5 in turn to enter the five-dimensional fiber coupling mirror 7. The excitation light is coupled with the micron-sized diamond containing the NV color center at the end of the multimode fiber probe 8. The diamond emits a fluorescence signal and returns along the multimode fiber along with the background scattered light signal inside the optical fiber. Adjust the five-dimensional fiber coupling mirror 7 so that the light path of the light outlet forms an angle of 8° with the incident light, and the returned fluorescence signal and scattered light enter the optical power meter 6 along the output light path. Adjust the central wavelength of the optical power meter 6 to 532 nm, set the optical power level to μW, and record the collection power at this time as P0 Close the aperture 4, remove the multimode fiber probe 8 at the end of the five-dimensional fiber coupling mirror 7, and connect the five-dimensional fiber coupling mirror 3 15 at the end of the adjustment light path to the five-dimensional fiber coupling mirror 7 through an additional multimode fiber, so that the adjustment light enters the optical power meter 6, and the collected power at this time is recorded as P 1 ; Adjust the attenuation plate 14 so that P 1 =P 0 ;

[0064] S2: Collection of reference signal containing background scattered light: Rewind the five-dimensional fiber coupling mirror 1 7 so that the outgoing light path coincides with the original incident light path, and allow the adjusted light to pass through the dichroic mirror 5, high-pass filter 9, five-dimensional fiber coupling mirror 2 10 and multimode optical fiber 11 along the outgoing light path and enter the spectrum analyzer 12. Set the working wavelength of the spectrum analyzer 12 to 400-1000 nm and the integration time to 1 s. Record the spectrum signal collected at this time as a signal without fluorescence background. Disconnect the multimode optical fiber connecting the five-dimensional fiber coupling mirror 3 15 and the five-dimensional fiber coupling mirror 1 7.

[0065] S3: Temperature coefficient correction: Submerge the multimode fiber probe 8 in a water bath, with the diamond particles about 1 cm away from the water surface. Set the temperature of the water bath to 20-80 degrees Celsius, set the default heating power, and set the temperature interval to 5°C. After heating to the specified temperature, wait for 15 minutes until the temperature is constant. Open the aperture 4, and the excitation light passes through the first reflector 3, the aperture 4, and the dichroic mirror 5 and enters the five-dimensional fiber coupling mirror 1 7. The returned fluorescence signal and background scattered light pass through the dichroic mirror 5, the high-pass filter 9, the five-dimensional fiber coupling mirror 2 10 and the multimode fiber 11 along the outgoing light path and enter the spectrum analyzer 12. Set the working wavelength of the spectrometer to 400-1000 nm, the integration time to 1 s, and the number of repetitions to 30 times. Record the spectral signal collected at this time as the test signal containing background light. After the signal collection is completed, close the aperture 4, heat up, and repeat the above operation until 80°C. Subtract the non-fluorescent background signal from the test signal containing background light to obtain a low-noise, true fluorescence spectrum. The real spectrum signal is fitted with an exponential function and a Lorentz function by a spectrum analyzer 12 to obtain the temperature coefficient of the fluorescence spectrum frequency shift, such as Figure 4 shown. Figure 4 The graph shows the change of the central peak position of the fluorescence spectrum with temperature. From the graph, the temperature coefficient (curve slope) and the following expression can be obtained: central peak wavelength = temperature * temperature coefficient + initial value.

[0066] S4: Dissolution test: Wrap a quartz glass dish with a volume of 1 mL with a dense sponge pad and place it on a horizontal table. Submerge the multimode fiber probe 8 in water, with the diamond particles about 3 mm from the water surface. Put the weighed 1 mmol NaOH particles into the water near the diamond particles. Open the aperture 4, and the excitation light passes through the first reflector 3, the aperture 4, and the dichroic mirror 5 and enters the five-dimensional fiber coupling mirror 1 7. The returned fluorescence signal and background scattered light pass through the dichroic mirror 5, the high-pass filter 9, the five-dimensional fiber coupling mirror 2 10 and the multimode fiber 11 along the outgoing light path and enter the spectrum analyzer 12. Set the working wavelength of the spectrum analyzer 12 to 400-1000 nm, the integration time to 1 s, and the repeated measurement time to 5 min. Record the spectral signal collected at this time as the fluorescence signal containing the background light.

[0067] S5: Signal processing: Subtract the non-fluorescent background signal from the fluorescent signal containing background light to obtain a low-noise, true fluorescence spectrum. Use a spectrum analyzer to fit the true spectrum signal with an exponential function and a Lorentz function. The temperature of the system after a trace amount of NaOH is dissolved in water can be obtained through the expression in S3. The temperature at different times can be plotted into a scatter plot to obtain the temperature change trend of the entire system. Figure 5 As shown, Figure 5 The temperature change trend of the entire system when NaOH is dissolved in water over time is shown.

[0068] Treatment of neural cells in this embodiment: Rinse the newly purchased 10.0 mm x 10.0 mm coverslips with double distilled water and dry them, immerse them in 75% disinfectant alcohol overnight and dry them, sterilize them with ultraviolet light for later use. Place the above sterilized cell coverslips in the center of a 48-well culture plate, drop 300 μL of 0.1 g / L poly-lysine (PDL) coating solution in the center of the well, incubate at 37°C for at least 2 hours, then remove the coating solution, wash with sterile 0.1 mol / L PBS 3 times, and dry them for later use. Add the pre-cultured mouse spinal neural stem cells to 20 ml of culture medium (10% FBS-5% HS-2mM Glutamine-DMEM), and perform cell counting and activity detection (Countess 3 FL fully automatic cell counter based on trypan blue staining). According to the cell counting results, adjust the cell solution concentration to 1 x 10 6 Cells were inoculated into the well plate according to a certain concentration rule (e.g. 1×10 cells / mL were inoculated into a 48-well plate). 5 After 24 h, the medium was replaced with 2% B27-1% N2-2mM Glutamine-Neurobasal (cell / well). The medium was fully replaced, and then half of the medium was replaced every three days.

[0069] Preparation of multimode fiber probe 8: Select 0.5 mL of nanodiamond suspension (NV color center concentration is about 100 ppm, size is about 50nm, concentration is 1 μg / μL) prepared by high temperature and high pressure method, place it in a closed container for ultrasonic dispersion for 20 minutes, and place it on a glass slide to dry after cleaning. Select 0.5 mL of UV ultraviolet curing glue and mix it with the dried nanodiamond powder, and ultrasonicate it for 30 minutes. Apply the glue mixture containing nanodiamond particles evenly on the end face of the multimode optical fiber. After the bonding is relatively firm, place it under a UV lamp for curing for 30 minutes, so that the film containing nanodiamond particles is firmly fixed on the end face of the optical fiber.

[0070] The other components of the optical fiber temperature measuring device of this embodiment are the same as those of the first embodiment.

[0071] In this embodiment, the method of using an optical fiber temperature measuring device to detect temperature changes during the spontaneous discharge of mouse spinal nerve cells specifically includes the following steps:

[0072] S1~S3, S5 are the same as S1~S3, S5 in Example 1.

[0073] S4: Neural cell test: Place a quartz cuvette with a volume of 1 mL on a horizontal table, and place 0.8 ml of culture medium containing mouse spinal neural stem cells inside. Submerge the multimode fiber probe 8 in water, and the nanodiamond film is about 3 mm from the water surface. Drop 0.01 mL of picrotoxin (selective neuroinhibitor), open the aperture 4, and the excitation light passes through the first reflector 3, aperture 4, and dichroic mirror 5 before entering the five-dimensional fiber coupling mirror 1 7. The returned fluorescence signal and background scattered light pass through the dichroic mirror 5, high-pass filter 9, five-dimensional fiber coupling mirror 2 10 and multimode optical fiber 11 along the outgoing light path and enter the spectrum analyzer 12. Set the working wavelength of the spectrometer to 400-1000 nm, the integration time to 1 s, and the repeated measurement time to 5 min. Record the spectrum signal collected at this time as the fluorescence signal containing the background light.

[0074] Those skilled in the art can understand that the above are only preferred examples of the invention and are not intended to limit the invention. Although the invention is described in detail with reference to the above examples, those skilled in the art can still modify the technical solutions recorded in the above examples or replace some of the technical features therein with equivalents. Any modification, equivalent replacement, etc. made within the spirit and principle of the invention shall be included in the protection scope of the invention.

Claims

1. An optical fiber temperature measurement device based on a solid-state quantum system, characterized in that: It comprises a semiconductor continuous laser (1), a non-polarizing beam splitter (2), a first reflector (3), an aperture (4), a dichroic mirror (5), an optical power meter (6), a five-dimensional fiber coupling mirror (1) (7), a multimode fiber probe (8), a high-pass filter (9), a five-dimensional fiber coupling mirror (2) (10), a multimode optical fiber (11), a spectrum analyzer (12), a second reflector (13), an attenuation plate (14) and a five-dimensional fiber coupling mirror (3) (15); The non-polarizing beam splitter (2) is arranged on the output light path of the semiconductor continuous laser (1) to divide the output light path of the semiconductor continuous laser (1) into an orthogonal excitation light path and an adjustment light path; the first reflector (3) is arranged on the excitation light path of the non-polarizing beam splitter (2); the aperture (4) and the dichroic mirror (5) are arranged in sequence in the direction of the reflected light of the first reflector (3); the optical power meter (6) and the five-dimensional fiber coupling mirror (7) are arranged in the output direction of the dichroic mirror (5); the multimode fiber probe (8) is connected to the optical fiber probe (9) and the optical power meter (6) and the five-dimensional fiber coupling mirror (7) are arranged in the output direction of the dichroic mirror (5); The end of the five-dimensional fiber coupling mirror (7); the high-pass filter (9) and the five-dimensional fiber coupling mirror (10) are arranged along the reflection direction of the multimode fiber probe (8) and are located after the dichroic mirror (5); the multimode optical fiber (11) connects the five-dimensional fiber coupling mirror (10) to the optical spectrum analyzer (12); the second reflector (13) is arranged on the adjustment optical path of the non-polarization beam splitter (2), and the attenuation plate (14) and the five-dimensional fiber coupling mirror (15) are arranged in the reflection direction of the second reflector (13); The multimode fiber probe (8) can be removed from the end of the five-dimensional fiber coupling mirror (7), and the five-dimensional fiber coupling mirror (15) at the end of the adjustment light path can be connected to the five-dimensional fiber coupling mirror (7) via an additional multimode optical fiber.

2. The optical fiber temperature measurement device based on a solid-state quantum system according to claim 1 is characterized in that: The multimode optical fiber probe (8) is a diamond probe containing an NV color center.

3. The optical fiber temperature measurement device based on a solid-state quantum system according to claim 1, characterized in that: The semiconductor continuous laser (1) has an operating wavelength of 532 nm, an output power of 0.1-100 mW, and an output light spot diameter of 2 mm.

4. The optical fiber temperature measurement device based on a solid-state quantum system according to claim 1, characterized in that: The non-polarization beam splitter (2) has an operating wavelength of 400-700 nm, a beam splitting ratio of 50:50, and a size of 10 mm.

5. The optical fiber temperature measurement device based on a solid-state quantum system according to claim 1, characterized in that: The diaphragm (4) is a continuously variable diaphragm adjusted by a lever, and has a maximum aperture of 15 mm.

6. The optical fiber temperature measurement device based on a solid-state quantum system according to claim 1, characterized in that: The dichroic mirror (5) is a long-wave pass dichroic mirror with a starting wavelength of 550 nm; the optical power meter (6) has an operating wavelength of 200-1100 nm and a receiving power range of 50 nW-50 mW.

7. The optical fiber temperature measurement device based on a solid-state quantum system according to claim 1, characterized in that: The specifications of the five-dimensional fiber coupling mirror 1 (7), the five-dimensional fiber coupling mirror 2 (10) and the five-dimensional fiber coupling mirror 3 (15) are exactly the same, with an anti-reflection range of 400-650 nm, a light aperture of 5 mm, a numerical aperture of 0.5 and a focal length of 6.67 mm.

8. The optical fiber temperature measurement device based on a solid-state quantum system according to claim 1, characterized in that: The high-pass filter (9) has a cut-off wavelength of 550 nm and a transmission wavelength of 560-1100 nm; the attenuation plate (14) is a continuously variable metal film neutral density filter coated with a 350-700 nm anti-reflection film.

9. The optical fiber temperature measurement device based on a solid-state quantum system according to claim 1, characterized in that: The multimode optical fibers in the multimode optical fiber (11) and the multimode optical fiber probe (8) are both multimode optical fibers with an operating wavelength of 400-2200 nm, a core diameter of 200 μm, and a numerical aperture of 0.

22.

10. A temperature measurement method of an optical fiber temperature measurement device based on a solid-state quantum system according to any one of claims 1 to 9, characterized in that: The steps include: Step 1: The semiconductor continuous laser (1) emits laser light, which is divided into orthogonal excitation light and adjustment light through the non-polarization beam splitter (2); the aperture (4) is opened, and the excitation light passes through the first reflector (3), the aperture (4), and the dichroic mirror (5) in sequence and enters the five-dimensional fiber coupling mirror (7), and the excitation light is coupled with the fluorescent medium at the end of the multimode fiber probe (8); the five-dimensional fiber coupling mirror (7) is adjusted so that the returned fluorescent signal and the background scattered light signal inside the optical fiber enter the optical power meter (6) along the output light path, and the collected power at this time is recorded as P0; the aperture (4) is closed, the multimode fiber probe (8) at the end of the five-dimensional fiber coupling mirror (7) is removed, and the five-dimensional fiber coupling mirror (15) at the end of the adjustment light path is connected to the five-dimensional fiber coupling mirror (7) through an additional multimode optical fiber, so that the adjustment light enters the optical power meter (6), and the collected power at this time is recorded as P1; Adjusting the attenuation plate (14) so ​​that P1 = P0; Step 2: Recall the five-dimensional fiber coupling mirror 1 (7) so that the outgoing light path coincides with the original incident light path, and the regulated light passes through the dichroic mirror (5), the high-pass filter (9), the five-dimensional fiber coupling mirror 2 (10) and the multimode optical fiber (11) along the outgoing light path, and enters the spectrum analyzer (12), and records the spectrum signal collected at this time as a signal without fluorescence background; disconnect the multimode optical fiber connecting the five-dimensional fiber coupling mirror 3 (15) and the five-dimensional fiber coupling mirror 1 (7); Step 3: placing the multimode optical fiber probe (8) in a temperature control device, adjusting the temperature control device to change the temperature of the fluorescent medium in the multimode optical fiber probe (8); opening the aperture (4), allowing the excitation light to pass through the first reflector (3), the aperture (4), and the dichroic mirror (5) before entering the five-dimensional optical fiber coupling mirror 1 (7), where the excitation light is coupled with the fluorescent medium at the end of the multimode optical fiber probe (8); the returned fluorescent signal and scattered light pass through the dichroic mirror (5), the high-pass filter (9), the five-dimensional optical fiber coupling mirror 2 (10) and the multimode optical fiber (11) and enter the spectrum analyzer (12), recording the spectrum signal collected at this time as a test signal containing background light; subtracting the non-fluorescent background signal obtained in step 2 from the test signal containing background light to obtain a low-noise, real fluorescence spectrum; fitting the real spectrum signal with an exponential function and a Lorentz function through the spectrum analyzer (12) to obtain the temperature coefficient of the fluorescence spectrum frequency shift and related expressions; Step 4: placing the multimode fiber probe (8) near the sample to be tested, opening the aperture (4), and allowing the excitation light to pass through the first reflector (3), the aperture (4), and the dichroic mirror (5) before entering the five-dimensional fiber coupling mirror 1 (7), wherein the excitation light is coupled with the fluorescent medium at the end of the multimode fiber probe (8), and the returned fluorescent signal and scattered light pass through the dichroic mirror (5), the high-pass filter (9), the five-dimensional fiber coupling mirror 2 (10), and the multimode optical fiber (11) and enter the spectrum analyzer (12), and the spectrum signal collected at this time is recorded as the fluorescent signal containing the background light; Step 5: Subtract the fluorescence signal containing background light obtained in step 4 from the background signal without fluorescence obtained in step 2, so as to obtain a low-noise, true fluorescence spectrum of the test sample; obtain the frequency shift of the fluorescence signal by data processing of the spectrum analyzer (12), and combine it with the relevant expression of the fluorescence spectrum frequency shift obtained in step 3 to obtain the temperature of the sample to be tested at different times.

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