A variable-temperature upconversion fluorescence lifetime measurement device

Abstract

This invention discloses a variable-temperature upconversion fluorescence lifetime measurement device, relating to the fields of precision optical measurement, precision temperature control, and weak signal detection. The device includes: an excitation optical path module, a sample temperature control module, a signal acquisition module, a data processing module, and a housing assembly. This invention enables variable-temperature fluorescence lifetime measurement above room temperature. It features a sample temperature probe that extends into the sample to accurately display its real-time temperature. A low-cost diode laser is used, and a signal source modulates the continuous laser into pulsed laser light. A high-precision oscilloscope replaces the dedicated TCSPC module for data acquisition, significantly reducing costs and facilitating widespread use. It enables rapid real-time detection, solving the problems of long acquisition times and slow speeds in traditional equipment, which are insufficient for real-time dynamic measurement.

Description

Technical Field

[0001] This utility model relates to the fields of precision optical measurement, precision temperature control and weak signal detection technology, and specifically to a variable temperature upconversion fluorescence lifetime measurement device. Background Technology

[0002] When a substance absorbs light of a specific wavelength, its atoms or molecules are excited to an excited state, and then transition back to the ground state within a very short time, emitting light with a wavelength different from the excitation wavelength. This luminescence is called fluorescence. Upconversion luminescence is a phenomenon in which a substance emits visible fluorescence after absorbing infrared excitation photons. Theoretically, the time required for the fluorescence intensity to decay to 1 / e of its maximum intensity after excitation stops is defined as the fluorescence lifetime. The fluorescence decay of an ideal pure component substance satisfies a single exponential decay equation: ,in, express t fluorescence intensity at time, Indicates the initial time ( t The maximum fluorescence intensity at (=0), τ Represents fluorescence lifetime, t This represents time. However, real-world samples are often complex systems, such as mixtures, defect states, or heterogeneous systems. The fluorescence emitted by complex systems is a combined result of the fluorescence of multiple components, and its fluorescence decay is a superposition of multiple exponentials. ,in τ i For the first i Fluorescence lifetime of each component A i For the first i The amplitude (weight) of each component. For complex systems in real samples, it is necessary to use software to perform multi-exponential fitting and calculate the average fluorescence lifetime using a weighted average method.

[0003] Fluorescence lifetime, as an inherent characteristic of matter, is closely related to the molecular structure and ambient temperature. Compared to fluorescence intensity measurement, fluorescence lifetime offers advantages such as independence from sample concentration, high detection accuracy, and less susceptibility to stray light and photobleaching. Upconversion fluorescence lifetime is widely used in cutting-edge fields such as rare-earth luminescence, temperature sensing, anti-counterfeiting technology, semiconductors, new energy (photovoltaics), intelligent sensing, environmental monitoring, biomedicine, and materials science. To further investigate the temperature response characteristics of materials, precise measurement of upconversion fluorescence lifetime under varying temperature conditions is necessary. Variable-temperature fluorescence lifetime measurement devices are used to accurately measure the fluorescence lifetime of samples under different temperature environments, providing reliable technical support for research and development and quality control in related fields.

[0004] Existing fluorescence lifetime testing devices have the following problems: 1. Most fluorescence lifetime testing devices are mainly used for measurements at room temperature. These devices cannot achieve continuous temperature control and real-time lifetime detection over a wide temperature range, making it difficult to meet the measurement requirements of upconversion materials at non-room temperature.

[0005] 2. Among the few instruments with variable temperature measurement functions, there are still many structural and usage defects. For example, there is no temperature detector inside the sample. The thermocouple is simply attached to the sample stage or the outer wall of the sample cell for temperature measurement. The temperature displayed by the instrument is the temperature of the heater or sample stage, not the actual temperature of the sample. This is because the internal temperature of the sample will lag and be lower than the temperature of the heater or sample stage, resulting in a deviation in the relationship between the measured sample fluorescence lifetime and temperature.

[0006] 3. High cost: Traditional fluorescence lifetime testing equipment often uses expensive components such as time-correlated single-photon counting technology (TCSPC) and pulsed lasers. The entire set of equipment costs hundreds of thousands to more than one million RMB. Instruments that can perform temperature-dependent fluorescence lifetime measurement are even more expensive, making it difficult for upconversion fluorescence lifetime measurement equipment to be widely used.

[0007] 4. Time-correlated single-photon counting is currently the most widely used fluorescence lifetime testing method, but it has the problems of long acquisition time and slow speed, making it difficult to meet the needs of real-time dynamic measurement. The long time required for single-point measurement significantly slows down the imaging speed and makes it impossible to capture dynamic processes. Utility Model Content

[0008] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a variable-temperature upconversion fluorescence lifetime measurement device. This device solves the technical problems of deviation between the temperature control design and the actual sample temperature, high cost, slow testing speed, and insufficient variable-temperature upconversion fluorescence lifetime testing capability of existing devices, and enables accurate, rapid, and low-cost measurement of upconversion fluorescence lifetime under different temperature conditions.

[0009] To achieve the above objectives, this utility model provides a variable-temperature upconversion fluorescence lifetime measurement device, including an excitation optical path module, a sample temperature control module, a signal acquisition module, a data processing module, and a housing assembly. The excitation optical path module, the sample temperature control module, and the signal acquisition module are all connected to the housing assembly, and the excitation optical path module is sequentially connected to the sample temperature control module, the signal acquisition module, and the data processing module.

[0010] Furthermore, the excitation optical path module includes a diode laser, a signal source, a laser collimator, a laser collimator support, and a slit controller; the diode laser is connected to the signal source to modulate the continuous laser into a pulsed laser; the laser collimator is mounted on the laser collimator support; the laser output from the diode laser passes sequentially through the laser collimator and the slit controller before irradiating the sample under test.

[0011] Furthermore, the sample temperature control module includes a sample cell, a sample temperature monitor, a sample temperature probe, a heater, a sample cell sealing cover, a high-transmittance quartz glass window, and a sample cell support. The sample cell is an isosceles right-angled triangular prism structure made of high thermal conductivity pure copper. A high-transmittance quartz glass window is embedded on the hypotenuse side, and the normal to the plane of the high-transmittance quartz glass window forms a 45° angle with the incident excitation ray. The top of the sample cell is equipped with a sample cell sealing cover, and a through hole is opened in the middle of the sample cell sealing cover. The sample temperature probe extends into the sample cell through the through hole and is electrically connected to the sample temperature monitor. The heater is attached to the outer wall of the sample cell, and the top of the sample cell support is equipped with an isosceles right-angled triangular prism-shaped cavity adapted to the sample cell, in which the sample cell is embedded.

[0012] Furthermore, the signal acquisition module includes a filter slot, a bandpass narrowband filter, a converging lens, and an avalanche photodiode detector (APD); the bandpass narrowband filter is detachably installed in the filter slot, and the half-bandwidth of the bandpass narrowband filter is ≤5nm; the converging lens and the avalanche photodiode detector (APD) are sequentially arranged behind the bandpass narrowband filter.

[0013] Furthermore, the data processing module includes an oscilloscope, a data transmission line, and a computer; the output terminal of the avalanche photodiode detector (APD) is connected to the input terminal of the oscilloscope via a data output line, and the oscilloscope is connected to the computer via a data transmission line; the oscilloscope has a bandwidth ≥ 400MHz.

[0014] Furthermore, the enclosure assembly includes a bottom surface, a first outer shell panel, a second outer shell panel, a third outer shell panel, a fourth outer shell panel, a first partition, a second partition, a top cover, a door, and a hinge. The bottom surface, the first outer shell panel, the second outer shell panel, the third outer shell panel, the fourth outer shell panel, and the top cover form a sealed enclosure. The first partition and the second partition are vertically arranged inside the enclosure. Light-transmitting holes are respectively opened on the first and second partitions. A slit controller is installed at the light-transmitting hole of the first partition, and a filter slot is installed at the light-transmitting hole of the second partition. The top cover is connected to the door via a hinge, and the door is located directly above the sample cell. A control panel window is provided on the second outer shell panel, and the control panels for the sample temperature monitor and the heater are embedded in the control panel window.

[0015] Furthermore, the sample cell is loaded with a solid powder sample or a liquid sample, and the sample height is higher than the upper edge of the high-transmittance quartz glass window.

[0016] Furthermore, the diode laser is selected based on the absorption wavelength of the sample to be tested, preferably a 980nm infrared diode laser, which is suitable for upconversion luminescence measurement scenarios containing rare earth elements such as Er, Yb, Ho, and Tm.

[0017] Furthermore, the diode laser is provided with a TTL interface for connecting an external signal source.

[0018] This invention also provides a method for measuring the lifetime of upconversion fluorescence at varying temperatures, based on the aforementioned device, comprising the following steps: Step 1: Sample loading: Open the hatch, remove the sample cell sealing cover, load the sample to be tested into the sample cell, the sample height must be higher than the upper edge of the high transmittance quartz glass window, place the sample cell in the recess of the sample cell support, insert the sample temperature probe into the sample, the end of the sample temperature probe must not be lower than the upper edge of the high transmittance quartz glass window to prevent light blocking, and cover the sample cell sealing cover. Step 2: Optical path adjustment: Select the corresponding bandpass narrowband filter according to the fluorescence wavelength to be measured and install it in the filter slot; start the diode laser and signal source to output pulsed laser; after the pulsed laser is collimated by the laser collimator and controlled by the slit controller, it illuminates the high transmittance quartz glass window, exciting the sample to produce upconversion fluorescence. At this time, the visible fluorescence emitted by the sample can be observed; close the chamber door. Step 3: Temperature control: Set the target temperature through the heater, collect the actual internal temperature of the sample in real time through the sample temperature probe, display the temperature data in real time through the sample temperature monitor, and fine-tune the heater to stabilize the value of the sample temperature detector at the target value. Step 4: Signal Acquisition: The fluorescence emitted by the sample is filtered out by a narrow bandpass filter to remove stray light, and then converged by a converging lens before being transmitted to an avalanche photodiode detector (APD). The APD converts the optical signal into an electrical signal and transmits it to an oscilloscope via a data output line. The oscilloscope displays the fluorescence decay curve of the sample in real time. Step 5: Lifetime Calculation: The oscilloscope displays and stores the fluorescence decay signal, the signal data is transmitted to the computer, and the fluorescence lifetime is calculated by performing e-exponential fitting on the fluorescence decay data curve using computer software. Step 6: Variable temperature measurement: Adjust the heater to different target temperatures, repeat steps 3-5, and complete the fluorescence lifetime measurement at multiple temperature points.

[0019] Compared with the prior art, the beneficial effects of this utility model are as follows: 1. Capable of precise temperature control for samples Existing temperature control testing devices control the temperature of the sample heating stage or sample pool, rather than the temperature of the sample itself, which deviates from the actual temperature of the sample. In contrast, this invention includes a sample temperature probe that extends into the sample and can accurately display the real-time temperature of the sample, resulting in more accurate temperature control.

[0020] 2. Low cost, compact structure, enabling rapid real-time detection. This invention employs a low-cost diode laser, modulates continuous laser light into pulsed laser light using a signal source, and uses a high-precision oscilloscope to replace the dedicated TCSPC module for data acquisition, significantly reducing costs. It enables rapid real-time detection, solving the problems of traditional equipment being bulky, having long acquisition times, being slow, and unable to meet real-time dynamic measurement requirements. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure and optical path of a variable-temperature upconversion fluorescence lifetime measurement device according to the present invention. The arrows in the diagram represent excitation light and fluorescence light. Figure 2 This is a schematic diagram of the sample cell structure of a variable-temperature upconversion fluorescence lifetime measurement device according to the present invention; Figure 3 This is a schematic diagram of the sample cell support structure of a variable-temperature upconversion fluorescence lifetime measurement device according to this utility model; Figure 4 This is a schematic diagram of the upper cover structure of the box of the variable temperature upconversion fluorescence lifetime measuring device according to the present invention; Figure 5 This is a schematic diagram of the overall appearance of the variable-temperature upconversion fluorescence lifetime measuring device after installation.

[0022] In the diagram: 1. Diode laser; 100. Signal source; 101. Laser collimator; 102. Laser collimator support; 103. Slit controller; 2. Sample cell; 21. Sample temperature monitor; 22. Sample temperature probe; 23. Heater; 201. Sample cell sealing cover; 202. High-transmittance quartz glass window; 3. Sample cell support; 31. Cavity; 32. Base; 33. Fixing screw hole; 4. Filter slot; 5. Bandpass / narrow band filter 6. Converging lens; 7. Avalanche photodiode detector (APD); 71. Data output line; 8. Oscilloscope; 9. Data transmission line; 10. Computer; 11. First partition; 12. Second partition; 13. First housing outer shell panel; 14. Second housing outer shell panel; 15. Third housing outer shell panel; 16. Fourth housing outer shell panel; 141. Control panel window; 17. Housing top cover; 18. Door; 19. Hinge; 20. Housing bottom surface. Detailed Implementation

[0023] The technical solution of this utility model will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] like Figures 1-5As shown, this utility model provides a variable-temperature upconversion fluorescence lifetime measurement device, including an excitation optical path module, a sample temperature control module, a signal acquisition module, a data processing module, and a housing assembly. The excitation optical path module, the sample temperature control module, and the signal acquisition module are all connected to the housing assembly. The sample temperature control module and the signal acquisition module are located inside the housing, and the data processing module is located outside the housing. The excitation optical path module is sequentially connected to the sample temperature control module, the signal acquisition module, and the data processing module.

[0025] The excitation optical path module includes a diode laser 1, a signal source 100, a laser collimator 101, a laser collimator support 102, and a slit controller 103. The diode laser 1 is equipped with a TTL interface, which is connected to the signal source 100. The pulsed laser output is achieved through the regulation of the signal source 100. The pulsed laser passes through the laser collimator 101 and the slit controller 103 in sequence to achieve laser collimation and beam control. The laser collimator 101 is mounted on the laser collimator support 102, and the slit of the slit controller 103 is at the same height as the output end of the laser collimator 101.

[0026] A sample temperature control module is installed after the slit controller 103. The sample temperature control module includes a sample cell 2, a sample temperature monitor 21, a sample temperature probe 22, a heater 23, a sample cell sealing cover 201, a high-transmittance quartz glass window 202, and a sample cell support 3. The sample cell 2 is an isosceles right-angled triangular prism structure made of high thermal conductivity pure copper. A high-transmittance quartz glass window 202 is embedded on its hypotenuse, and the normal to the plane containing the high-transmittance quartz glass window 202 forms a 45° angle with the incident excitation ray. A sample cell sealing cover 2 is provided on the top of the sample cell 2. 01. A through hole is provided in the middle of the sample cell sealing cover 201; the sample temperature probe 22 extends into the sample cell 2 through the through hole and is electrically connected to the sample temperature monitor 21; the lowest point of the sample temperature probe 22 must not be lower than the upper edge of the high light transmittance quartz glass window 202 to prevent light blockage; the heater 23 is attached to the outer wall of the sample cell 2; the top of the sample cell support 3 is provided with an isosceles right-angled triangular prism cavity 31 adapted to the sample cell 2; the bottom is provided with a base 32; the base 32 is provided with fixing screw holes 33; it is fixed to the box body by bolts; the sample cell 2 is embedded in the cavity 31.

[0027] The signal acquisition module includes a filter slot 4, a bandpass narrowband filter 5, a converging lens 6, and an avalanche photodiode detector (APD7). The filter slot 4 is provided at the light-passing hole of the second partition 12. The bandpass narrowband filter 5 is detachably installed in the filter slot 4, and the half-bandwidth of the bandpass narrowband filter 5 is ≤5nm. The converging lens 6 and the avalanche photodiode detector (APD7) are arranged in sequence behind the bandpass narrowband filter 5, and the light inlet of the avalanche photodiode detector (APD7) is located at the focal point of the converging lens 6.

[0028] The data processing module includes an oscilloscope 8, a data transmission line 9, and a computer 10; the output terminal of the avalanche photodiode detector APD7 is connected to the input terminal of the oscilloscope 8 via a data output line 71, and the oscilloscope 8 is connected to the computer 10 via the data transmission line 9 to realize signal display, storage, and data fitting; the bandwidth of the oscilloscope 8 is ≥400MHz.

[0029] The enclosure assembly includes a bottom surface 20, a first outer shell panel 13, a second outer shell panel 14, a third outer shell panel 15, a fourth outer shell panel 16, a first partition 11, a second partition 12, a top cover 17, a door 18, and a hinge 19. The bottom surface 20, the first outer shell panel 13, the second outer shell panel 14, the third outer shell panel 15, the fourth outer shell panel 16, and the top cover 17 enclose a sealed enclosure, and a first partition 11 is vertically arranged inside the enclosure. The first partition 11 and the second partition 12 are respectively provided with light-transmitting holes. A slit controller 103 is installed at the light-transmitting hole of the first partition 11 and a filter slot 4 is installed at the light-transmitting hole of the second partition 12. The top cover 17 of the box is connected to the door 18 through the hinge 19. The door 18 is located directly above the sample pool 2. The outer shell plate 14 of the second box is provided with a control panel window 141. The control panels of the sample temperature monitor 21 and the heater 23 are embedded in the control panel window 141.

[0030] A small hole is made on the fourth housing outer plate 16, the size of which is referenced to the data output line 71 of the avalanche photodiode detector APD7; a small hole is made on the first housing outer plate 13, which allows the laser collimator 101 to pass through.

[0031] Wiring was completed at all openings and windows on the outer casing, and then a unified sealing treatment was applied.

[0032] The sample cell 2 is loaded with solid powder or liquid samples, and the sample height must be higher than the upper edge of the high-transmittance quartz glass window 202.

[0033] The diode laser 1 is selected according to the absorption wavelength of the sample to be tested, preferably a 980nm infrared diode laser, which is suitable for upconversion luminescence measurement scenarios containing rare earth elements such as Er, Yb, Ho, and Tm.

[0034] This invention also provides a method for measuring the upconversion fluorescence lifetime at varying temperatures, based on the aforementioned apparatus, to measure La2MoO6:Er 3+ Taking the temperature-dependent upconversion fluorescence lifetime of a powder sample as an example, the following steps are included: Step 1: Sample loading: Open the hatch 18, remove the sample cell sealing cover 201, load the sample to be tested into the sample cell 2, the sample height must be higher than the upper edge of the high transmittance quartz glass window 202, place the sample cell 2 into the cavity 31 of the sample cell support 3, insert the sample temperature probe 22 into the sample, the end of the sample temperature probe 22 must not be lower than the upper edge of the high transmittance quartz glass window 202 to prevent light blocking, and cover the sample cell sealing cover 201. Step 2: Optical path adjustment: to measure La2MoO6:Er 3+ Taking the emitted 553nm green fluorescence lifetime as an example, a 553nm bandpass narrow-band filter 5 is selected and installed in the filter slot 4; the diode laser 1 and signal source 100 are started to output pulsed laser; after the pulsed laser is collimated by the laser collimator 101 and controlled by the slit controller 103, it illuminates the high-transmittance quartz glass window 202, exciting the sample to generate upconversion fluorescence, at which time the visible fluorescence emitted by the sample can be observed; the chamber door 18 is closed; Step 3: Temperature control: Set the target temperature to 25℃ through heater 23, sample temperature probe 22 collects the internal temperature of the sample in real time, sample temperature monitor 21 displays the sample temperature, and fine-tune heater 23 to stabilize the sample temperature displayed by sample temperature monitor 21 at 25℃. Step 4: Signal Acquisition: After collimation and beam control, the pulsed laser shines on the sample through the high-transmittance quartz glass window 202, exciting the sample to emit green upconversion fluorescence; the fluorescence is filtered by the bandpass narrow-band filter 5 to remove stray light, and then focused by the converging lens 6 before being transmitted to the avalanche photodiode detector APD7. The avalanche photodiode detector APD7 converts the optical signal into an electrical signal and transmits it to the oscilloscope 8 through the data output line 71; Step 5: Lifetime calculation: The fluorescence decay curve is displayed on the oscilloscope 8, and the signal data is transmitted to the computer 10. The software fits the data and finds that the lifetime of the green fluorescence at 553nm of the sample at 25℃ is 197.4μs. Step 6: Repeat the measurement: Set the target temperature to 75℃ and 125℃ in sequence, and repeat steps 3-5. The fluorescence lifetimes at the corresponding temperatures were measured to be 179.7μs and 166.7μs, respectively, to complete the variable temperature measurement.

[0035] The above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A variable-temperature upconversion fluorescence lifetime measurement device, characterized in that: It includes an excitation optical path module, a sample temperature control module, a signal acquisition module, a data processing module, and a housing assembly. The excitation optical path module, the sample temperature control module, and the signal acquisition module are all connected to the housing assembly. The excitation optical path module is sequentially connected to the sample temperature control module, the signal acquisition module, and the data processing module.

2. The variable-temperature upconversion fluorescence lifetime measurement device according to claim 1, characterized in that: The excitation optical path module includes a diode laser (1), a signal source (100), a laser collimator (101), a laser collimator support (102), and a slit controller (103); the diode laser (1) is connected to the signal source (100), and the laser collimator (101) is mounted on the laser collimator support (102); the laser output from the diode laser (1) passes through the laser collimator (101) and the slit controller (103) in sequence before irradiating the sample to be tested.

3. The variable-temperature upconversion fluorescence lifetime measurement device according to claim 1, characterized in that: The sample temperature control module includes a sample cell (2), a sample temperature monitor (21), a sample temperature probe (22), a heater (23), a sample cell sealing cover (201), a high-transmittance quartz glass window (202), and a sample cell support (3); the sample cell (2) is an isosceles right-angled triangular prism structure, and a high-transmittance quartz glass window (202) is embedded on the side where its hypotenuse is located. The normal of the plane where the high-transmittance quartz glass window (202) is located forms a 45° angle with the incident excitation light. The sample cell (2) is provided with a sample cell sealing cover (201) at the top, and a through hole is provided in the middle of the sample cell sealing cover (201); the sample temperature probe (22) extends into the sample cell (2) through the through hole and is electrically connected to the sample temperature monitor (21); the heater (23) is attached to the outer wall of the sample cell (2), and the sample cell support (3) is provided with an isosceles right-angled triangular prism cavity (31) adapted to the sample cell (2) at the top, and the sample cell (2) is embedded in the cavity (31).

4. The variable-temperature upconversion fluorescence lifetime measurement device according to claim 1, characterized in that: The signal acquisition module includes a filter slot (4), a bandpass narrowband filter (5), a converging lens (6), and an avalanche photodiode detector (APD) (7); the bandpass narrowband filter (5) can be detachably installed in the filter slot (4), and the half bandwidth of the bandpass narrowband filter (5) is ≤5nm; the converging lens (6) and the avalanche photodiode detector (APD) (7) are arranged in sequence behind the bandpass narrowband filter (5).

5. The variable-temperature upconversion fluorescence lifetime measurement device according to claim 4, characterized in that: The data processing module includes an oscilloscope (8), a data transmission line (9), and a computer (10); the output terminal of the avalanche photodiode detector (APD) (7) is connected to the input terminal of the oscilloscope (8) via a data output line (71), and the oscilloscope (8) is connected to the computer (10) via the data transmission line (9); the bandwidth of the oscilloscope (8) is ≥400MHz.

6. The variable-temperature upconversion fluorescence lifetime measurement device according to claim 1, characterized in that: The enclosure assembly includes a bottom surface (20), a first outer shell panel (13), a second outer shell panel (14), a third outer shell panel (15), a fourth outer shell panel (16), a first partition (11), a second partition (12), a top cover (17), a door (18), and a hinge (19); the bottom surface (20), the first outer shell panel (13), the second outer shell panel (14), the third outer shell panel (15), the fourth outer shell panel (16), and the top cover (17) enclose a sealed enclosure, and a first partition (18) is vertically arranged inside the enclosure. 1) The second partition (12) has light-transmitting holes on the first partition (11) and the second partition (12). A slit controller (103) is installed at the light-transmitting hole of the first partition (11), and a filter slot (4) is installed at the light-transmitting hole of the second partition (12). The top cover (17) of the box is connected to the door (18) through a hinge (19). The door (18) is located directly above the sample pool (2). The outer shell plate (14) of the second box is provided with a control panel window (141). The control panels of the sample temperature monitor (21) and the heater (23) are installed in the control panel window (141).

7. The variable-temperature upconversion fluorescence lifetime measurement device according to claim 3, characterized in that: The sample cell (2) contains a solid powder sample or a liquid sample, the height of which is higher than the upper edge of the high-transmittance quartz glass window (202).

8. The variable-temperature upconversion fluorescence lifetime measurement device according to claim 2, characterized in that: The diode laser (1) is an infrared diode laser.

9. The variable-temperature upconversion fluorescence lifetime measurement device according to claim 2, characterized in that: The diode laser (1) is provided with a TTL interface for connecting an external signal source (100).

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