A fluorescence lifetime detection device for pulse current excitation

Abstract

The present invention provides a fluorescence lifetime detection device for pulse current excitation, comprising: a central control unit, used to send out a trigger signal, wherein the trigger signal comprises a first trigger signal, a second trigger signal, and a third trigger signal; a pulse generator, used to generate a pulse current under the action of the first trigger signal, wherein the pulse current acts on a sample to be tested; a laser, used to send out a pulse laser with the same frequency as the pulse current under the action of a second trigger signal; a data acquisition unit, used to irradiate the sample to be tested after processing the pulse laser, and collect the sample fluorescence generated by the sample to be tested before and after the pulse current acts on the sample to be tested, and convert the sample fluorescence into a sample fluorescence intensity electrical signal; and a data processing and imaging unit, used to process the sample fluorescence intensity electrical signal to obtain a sample fluorescence lifetime image.

Description

Technical Field

[0001] The present disclosure relates to the technical field of fluorescence lifetime detection, and in particular to a fluorescence lifetime detection device for pulse current excitation. Background Art

[0002] Fluorescent materials can absorb photons irradiated on them, so that ground state electrons are excited to an excited state. When the excited state electrons are slightly disturbed, they return to the ground state in the form of spontaneous radiation transition and non-radiative transition. The fluorescence lifetime of fluorescent materials is mainly determined by the spontaneous radiation transition lifetime and the non-radiative transition lifetime.

[0003] The fluorescence lifetime of a fluorescent substance refers to the time required for the fluorescence intensity of the fluorescent substance to drop to 1 / e of the maximum fluorescence intensity when the excitation stops. From the fluorescence lifetime, we can obtain information such as the carrier dynamics, radiation lifetime, non-radiation lifetime, and energy transfer. Compared with the photoluminescence intensity, the fluorescence lifetime is not affected by the excitation intensity, so we can obtain more accurate information when the fluorescent substance emits fluorescence.

[0004] At present, there are several methods for measuring fluorescence lifetime, including time-correlated single-photon counting (TCSPC), strobe techniques, phase modulation methods, streak cameras, and up-conversion methods. TCSPC is the main fluorescence lifetime measurement technology currently used. Fluorescence lifetime is usually in the order of picoseconds to microseconds. When measuring on such a short time scale, TCSPC technology is the most mature and accurate test method.

[0005] The fluorescence lifetime will change due to the influence of temperature, environment, charge, and external field. By analyzing the change information of fluorescence lifetime with the change of environment, temperature, charge, external field and other factors, we can obtain the change information of physical and chemical properties of fluorescent substances with the change of the above conditions.

[0006] Current excitation is required in fields such as LEDs, electrolasers, photodetectors and solar cells. The instantaneous changes in the physical and chemical properties of samples with current injection during current excitation are extremely important in studying the principles of such devices and improving device performance. However, there is currently no effective means to obtain information on the instantaneous changes in the physical and chemical properties of samples in the above fields when current is injected.

[0007] Conventional methods for testing the luminescence lifetime of the above-mentioned neighborhood include TCSPC technology and transient electroluminescence (Tr-EL). The working principles of TCSPC fluorescence lifetime measurement and Tr-EL device are as follows: TCSPC fluorescence lifetime measurement uses a pulsed laser to excite the sample to make it transition from the ground state to the excited state, and collects fluorescence intensity information at different times through APD (Avalanche PhotoDiode) or PMT (Photomultiplier Tube), which is collected and stored through a counter, and the fluorescence lifetime information of the sample to be tested is obtained through data processing; the Tr-EL device is excited by a pulsed electrical signal, and collects electroluminescence intensity information at different times through APD or PMT, which is collected and stored through a counter, and the transient electroluminescence information of the sample to be tested is obtained through data processing. However, the TCSPC fluorescence lifetime measurement device is limited by the fact that the device excitation mode is light excitation, and it is difficult to obtain the exciton information of the sample when the carrier is injected by the electrode, and it is also impossible to know the carrier or exciton information when a single electron or single hole is injected; and Tr-EL is limited by the fact that it can only test the light intensity information of the electroluminescent sample at different times, and it is impossible to obtain the changes in the physical and chemical properties of the sample when the carrier is injected at a single time, and it is also impossible to test the changes in the physical and chemical properties of the non-luminescent sample under electrical excitation at different times of carrier injection. However, in the research of devices such as LEDs, electrolasers, photodetectors, and solar cells, the information such as the charged state of the sample at different times of carrier injection, the influence of the injected carriers on the dynamics of the excited state, the diffusion of carriers, and the filling of defect states is extremely important for reflecting the performance of the above-mentioned devices. Therefore, the present invention provides a device for detecting the changes in fluorescence lifetime at different times before and after pulse current excitation, and the device is characterized in that the time difference between the pulse current signal and the pulse light signal is adjusted by a delay device in combination with electrical excitation to detect the fluorescence lifetime, and the fluorescence lifetime information of the sample under different time differences between the pulse current signal and the pulse light signal is collected. Summary of the invention

[0008] 1. Technical issues to be resolved

[0009] Based on the above problems, the present disclosure provides a fluorescence lifetime detection device for pulse current excitation to alleviate technical problems in the prior art that the instantaneous change information of the physical and chemical properties of samples such as LEDs, electrolasers, photodetectors and solar cells cannot be effectively obtained when current is injected.

[0010] (II) Technical solution

[0011] The present disclosure provides a fluorescence lifetime detection device for pulse current excitation, comprising:

[0012] A central control unit, used to send a trigger signal, wherein the trigger signal includes a first trigger signal, a second trigger signal, and a third trigger signal;

[0013] A pulse generator, used for generating a pulse current under the action of a first trigger signal, wherein the pulse current acts on the sample to be tested;

[0014] A laser, used for emitting a pulse laser with the same frequency as the pulse current under the action of a second trigger signal;

[0015] A data acquisition unit, used to irradiate the sample to be tested after processing the pulse laser, collect the sample fluorescence generated by the sample to be tested before and after being acted upon by the pulse current, and convert the sample fluorescence into an electrical signal of sample fluorescence intensity; and

[0016] The data processing and imaging unit is used to process the sample fluorescence intensity electrical signal to obtain the sample fluorescence lifetime image.

[0017] In the embodiment of the present disclosure, the data acquisition unit includes:

[0018] A microscopic imaging system, used to irradiate the sample to be tested after processing the pulse laser, and collect the sample fluorescence generated by the sample to be tested before and after being acted upon by the pulse current;

[0019] A photodetector, used to receive the sample fluorescence and convert it into an electrical signal of fluorescence intensity; and

[0020] A counter is used to measure and store the fluorescence intensity electrical signal.

[0021] In the disclosed embodiment, the microscopic imaging system processes the pulsed laser and then irradiates the sample to be tested. The sample fluorescence generated by the sample to be tested before being acted upon by the pulsed current is the first fluorescence, and the sample fluorescence generated by the sample to be tested after being acted upon by the pulsed current is the second fluorescence.

[0022] In an embodiment of the present disclosure, the microscopic imaging system comprises:

[0023] A convex lens group, capable of converting the pulsed laser into parallel light and emitting the parallel light;

[0024] A dichroic mirror, used for receiving the parallel light and reflecting it;

[0025] An objective lens, used for receiving the parallel light reflected by the dichroic mirror, focusing the parallel light and irradiating it onto the sample to be tested, and collecting the sample fluorescence generated by the sample to be tested before and after being acted upon by the pulse current;

[0026] A filter that can pass light of the same wavelength as the light emitted by the sample to be tested, is used to filter stray light and laser signals, and only passes light of the sample's fluorescence wavelength; and

[0027] The convex lens is used to focus the sample fluorescence transmitted through the filter onto the optical fiber, and transmit the sample fluorescence to the photodetector through the optical fiber.

[0028] In the disclosed embodiment, the microscopic imaging system further comprises:

[0029] The eyepiece is used to cooperate with the movable reflector to observe the state of the objective lens focusing on the sample to be tested.

[0030] In the embodiment of the present disclosure, the pulse generator can emit pulse currents of different frequencies, sizes and shapes under the action of the first trigger signal.

[0031] In the disclosed embodiment, the laser is a frequency-adjustable short-pulse laser.

[0032] In the disclosed embodiment, a delay device is provided in the central control unit, and the delay device is used to adjust the time difference between the first trigger signal and the second trigger signal.

[0033] In the disclosed embodiment, the delay device is also used to regulate the sending of the third trigger signal to the counter to coordinate the operation of various components.

[0034] In the embodiment of the present disclosure, the delay device is an optical delay device or an electronic board delay device.

[0035] (III) Beneficial effects

[0036] It can be seen from the above technical solutions that the fluorescence lifetime detection device for pulse current excitation disclosed in the present invention has at least one or part of the following beneficial effects:

[0037] (1) The instantaneous lifetime of current injection when the sample is excited by pulse current is measured;

[0038] (2) The current response process of the electrically excited sample is measured;

[0039] (3) It is possible to obtain the fluorescence lifetime change of the sample under pulse current excitation, regardless of whether the sample emits light or not under electrical excitation; and

[0040] (4) It is possible to obtain information on the instantaneous changes in the physical and chemical properties of the sample caused by pulse current stimulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a schematic diagram of the composition of the fluorescence lifetime detection device for pulse current excitation according to an embodiment of the present disclosure.

[0042] Figure 2 This is an optical path diagram of a data acquisition unit of a fluorescence lifetime detection device for pulse current excitation according to an embodiment of the present disclosure.

[0043] Figure 3 This is a pulse sequence diagram of a fluorescence lifetime detection device for pulse current excitation according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0044] The present disclosure provides a fluorescence lifetime detection device for pulse current excitation, which can detect the fluorescence lifetime at each moment during the pulse current excitation process. It is a device for electrically excited luminescence detection of fluorescence lifetime, and is suitable for detecting fluorescence lifetime changes in the electrical response process of devices in the fields of LEDs, electrolasers, photodetectors and solar cells.

[0045] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0046] In an embodiment of the present disclosure, a fluorescence lifetime detection device for pulse current excitation is provided, such as Figure 1 As shown, the fluorescence lifetime detection device includes: a central control unit for sending a trigger signal; a pulse generator for receiving a first trigger signal sent by the central control unit and generating a pulse current under the action of the first trigger signal, wherein the pulse current acts on the sample to be tested; a laser for receiving a second trigger signal sent by the central control unit and emitting a pulse laser with the same frequency as the pulse current under the action of the second trigger signal, wherein the pulse laser acts on the sample to be tested; a data acquisition unit for processing the pulse laser to form a focused light signal to irradiate the sample to be tested, for receiving a third trigger signal sent by the central control unit and under the action of the third trigger signal, collecting the unexcited fluorescence of the sample to be tested after the action of the pulse laser when the pulse current is not excited, and the excited fluorescence of the sample to be tested after the action of the pulse laser when the pulse current is excited, and processing the unexcited fluorescence and the excited fluorescence into unexcited fluorescence lifetime electrical signal data and excited fluorescence lifetime electrical signal data; and a data processing and imaging unit for processing the unexcited fluorescence lifetime electrical signal data and the excited fluorescence lifetime electrical signal data to obtain an unexcited fluorescence lifetime image and an excited fluorescence lifetime image.

[0047] In the embodiment of the present disclosure, the data acquisition unit includes: a microscopic imaging system, which is used to collect the sample fluorescence and form it into an unexcited fluorescence signal or an excited fluorescence signal; a photodetector, which is used to receive the unexcited fluorescence signal or the excited fluorescence signal and convert it into the unexcited fluorescence lifetime electrical signal and the excited fluorescence lifetime electrical signal; a counter, which can receive the unexcited fluorescence lifetime electrical signal and the excited fluorescence lifetime electrical signal, organize them into the unexcited fluorescence lifetime electrical signal data and the excited fluorescence lifetime electrical signal data, and record and store them.

[0048] Furthermore, the photodetector may be an APD or a PMT.

[0049] In the disclosed embodiment, the microscopic imaging system includes: a convex lens group, which can convert pulsed laser light emitted by a laser into parallel light and emit it; a dichroic mirror, which is used to receive the parallel light and reflect it; an objective lens, which is used to receive the parallel light reflected by the dichroic mirror, focus it and irradiate it on the sample to be tested, so that the sample to be tested emits the excitation fluorescence; a filter, which can pass light with the same wavelength as the light emitted by the sample to be tested, and is used to filter out stray light in the sample fluorescence emitted by the sample to be tested and passing through the objective lens and the dichroic mirror; a convex lens, which is used to focus the sample fluorescence passing through the filter on the optical fiber, and form the sample fluorescence into the unexcited fluorescence signal or the excitation fluorescence signal through the optical fiber.

[0050] Furthermore, the microscopic imaging system further comprises: an eyepiece, which is used to observe the state of the objective lens focusing on the sample to be measured through a movable reflector.

[0051] In the embodiment of the present disclosure, the pulse generator can emit pulse currents of different frequencies, sizes and shapes under the action of the first trigger signal.

[0052] In the disclosed embodiment, the laser is a frequency-adjustable short-pulse laser.

[0053] In the disclosed embodiment, a delay device is provided in the central control unit, and the delay device is used to adjust the time difference between the first trigger signal and the second trigger signal.

[0054] Furthermore, the delay device is an optical delay device or an electronic board delay device. The delay device can be realized by an optical delay table or an electronic board card, and the delay device is used to adjust the time difference between the first trigger signal (or current pulse signal) and the second trigger signal (or pulse light signal), so as to test the fluorescence lifetime information of the sample at different times when the pulse current acts; at the same time, the third trigger signal is sent to the counter in time-sharing to obtain the electrical signal data of the fluorescence intensity at different times, and coordinate the operation of each component.

[0055] In the embodiment disclosed herein, the fluorescence lifetime of the sample is measured by pulse light excitation at set moments before and after the action of the pulse current, and the time difference between the pulse current and the pulse light is realized by a delay device in the central control system. The fluorescence lifetime under the action of the pulse current is measured in the above manner, thereby obtaining information on the fluorescence lifetime at different moments of the pulse current excitation, and a two-dimensional image of the fluorescence lifetime of the sample to be measured at different moments of the pulse current action is drawn by the data processing and imaging unit.

[0056] The microscopic imaging system comprises: a convex lens group, which can convert pulsed laser light emitted by a laser into parallel light and emit it; a dichroic mirror, which is used to receive the parallel light and reflect it; an objective lens, which is used to receive the parallel light reflected by the dichroic mirror, focus the parallel light and irradiate it on a sample to be tested, so that the sample to be tested emits the excitation fluorescence; a filter, which can pass light with the same wavelength as the light emitted by the sample to be tested, and is used to filter stray light in the sample fluorescence emitted by the sample to be tested and passing through the objective lens and the dichroic mirror; and a convex lens, which is used to focus the sample fluorescence passing through the filter on an optical fiber, and form the sample fluorescence into the unexcited fluorescence signal or the excitation fluorescence signal through the optical fiber.

[0057] In the embodiment of the present disclosure, the pulse generator can generate square or other types of pulse current signals with different sizes, pulse widths and frequencies under the first trigger signal to act on the sample to be tested.

[0058] In the embodiment of the present disclosure, the sample to be tested is an electrically excited sample, which is placed on a sample stage and connected to the output end of a pulse generator to be excited by a pulse current.

[0059] The laser is a frequency-adjustable short-pulse laser.

[0060] The first trigger signal, the second trigger signal and the third trigger signal have the same frequency.

[0061] In an embodiment of the present invention, the data acquisition unit includes: a microscopic imaging system such as Figure 2 As shown, it includes: a convex lens group, which is used to convert the pulse light signal emitted by the laser into parallel light; an objective lens, which is used to focus the parallel light and irradiate it on the sample, and collect the sample light at the same time; a dichroic mirror, which is used to reflect the parallel light converted by the convex lens group to the objective lens, and can pass the sample light collected by the objective lens; a filter, which is used to filter stray light and laser signals, and only pass the light of the wavelength of the sample to be measured; an eyepiece, which is used to observe whether the objective lens is focused on the sample;

[0062] In an embodiment of the present invention, the APD or PMT is used to collect and convert the fluorescence lifetime signals at different times before and after the pulse current into electrical signals, and process them into electrical signal data of the fluorescence lifetime at different times; and the counter is used to count and store the above electrical signals.

[0063] In an embodiment of the present invention, the data acquisition unit further includes optical elements such as a convex lens and an optical fiber;

[0064] In an embodiment of the present invention, a delay device is provided in the central control unit, and the delay device can be realized by optical delay or electronic board. The delay device is used to adjust the time difference between the first trigger signal and the second trigger signal, so as to obtain the fluorescence lifetime information of the sample to be tested at different times when the pulse current acts; at the same time, the third trigger signal is sent to the counter in a time-sharing manner to obtain the electrical signal data of the fluorescence intensity at different times, and coordinate the operation of each component.

[0065] The above is the fluorescence lifetime information collected by light excitation at a certain moment before and after the pulse current. The time difference between the pulse laser and the pulse current is realized by the delay device in the central control unit, and the fluorescence lifetime information of the pulse light excitation at different moments of pulse current excitation is realized.

[0066] The data processing and imaging unit then processes the electrical signals stored in the counter and generates fluorescence lifetime images at different moments of the pulse current action.

[0067] So far, the embodiments of the present disclosure have been described in detail in conjunction with the accompanying drawings. It should be noted that the implementation methods not shown or described in the drawings or the body of the specification are all forms known to ordinary technicians in the relevant technical field and are not described in detail. In addition, the above definitions of each element and method are not limited to the various specific structures, shapes or methods mentioned in the embodiments, and ordinary technicians in the field can simply change or replace them.

[0068] Based on the above description, those skilled in the art should have a clear understanding of the fluorescence lifetime detection device for pulse current excitation disclosed in the present invention.

[0069] In summary, the present disclosure provides a fluorescence lifetime detection device for pulse current excitation. The device adopts a combination of pulse current excitation and TCSPC technology to achieve the measurement of the instantaneous lifetime of current injection when the pulse current excites the sample. The present invention is suitable for measuring the current response process of the electrically excited sample. One feature of the present invention is that, regardless of whether the sample emits light or not under electrical excitation, the fluorescence lifetime change of the sample during pulse current excitation can be obtained, and the instantaneous physical and chemical property change information of the sample pulse current excitation can be obtained by analysis. Different from the traditional fluorescence lifetime test device and Tr-EL test device, the device uses pulse current as the excitation source, combined with optical or electronic delayed pulse laser, to collect fluorescence lifetime information at different times after electrical excitation. The invention is suitable for studying the diffusion of carriers, exciton dynamics and carrier dynamics in the electrical injection process of devices such as LEDs, electrolasers, photodetectors and solar cells. It can also test the fluorescence lifetime of single electrons and single holes at different times of injection, and can study the defect state and charge of the sample to be tested during the carrier injection process by analyzing the fluorescence lifetime change. It is also possible to test the change in fluorescence lifetime under electrical excitation without luminescence, and to obtain information such as sample charging and carrier diffusion during carrier injection by analyzing the changes.

[0070] It should also be noted that the directional terms mentioned in the embodiments, such as "upper", "lower", "front", "back", "left", "right", etc., are only reference directions of the drawings and are not intended to limit the scope of protection of the present disclosure. Throughout the drawings, the same elements are represented by the same or similar reference numerals. Conventional structures or configurations will be omitted when they may cause confusion in the understanding of the present disclosure.

[0071] Moreover, the shapes and sizes of the components in the figures do not reflect the real size and proportion, but only illustrate the contents of the embodiments of the present disclosure. In addition, in the claims, any reference symbols between brackets shall not be constructed as limiting the claims.

[0072] Unless otherwise indicated, the numerical parameters in this specification and the appended claims are approximate values ​​and can vary according to the desired properties obtained through the content of the present disclosure. Specifically, all numbers used in the specification and claims to express the content of the composition, reaction conditions, etc., should be understood to be modified by the term "about" in all cases. In general, the meaning of the expression is to include a variation of ±10% in some embodiments, ±5% in some embodiments, ±1% in some embodiments, and ±0.5% in some embodiments by a specific number.

[0073] Furthermore, the word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

[0074] The ordinal numbers used in the specification and claims, such as "first", "second", "third", etc., to modify the corresponding elements, do not themselves mean that the elements have any ordinal numbers, nor do they represent the order of one element and another element, or the order in the manufacturing method. The use of these ordinal numbers is only used to clearly distinguish a component with a certain name from another component with the same name.

[0075] In addition, unless the steps are specifically described or must occur in sequence, the order of the above steps is not limited to the above list, and can be changed or rearranged according to the required design. And the above embodiments can be mixed and matched with each other or with other embodiments based on design and reliability considerations, that is, the technical features in different embodiments can be freely combined to form more embodiments.

[0076] Those skilled in the art will appreciate that the modules in the devices in the embodiments may be adaptively changed and set in one or more devices different from the embodiments. The modules or units or components in the embodiments may be combined into one module or unit or component, and in addition they may be divided into multiple submodules or subunits or subcomponents. All features disclosed in this specification (including the accompanying claims, abstracts and drawings) and all processes or units of any method or device disclosed in this manner may be combined in any combination, except that at least some of such features and / or processes or units are mutually exclusive. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstracts and drawings) may be replaced by an alternative feature that provides the same, equivalent or similar purpose. Furthermore, in a unit claim that lists several devices, several of these devices may be embodied by the same hardware item.

[0077] Similarly, it should be understood that in order to streamline the present disclosure and aid in understanding one or more of the various disclosed aspects, in the above description of the exemplary embodiments of the present disclosure, the various features of the present disclosure are sometimes grouped together into a single embodiment, figure, or description thereof. However, this disclosed method should not be interpreted as reflecting the following intention: the claimed disclosure requires more features than the features explicitly recited in each claim. More specifically, as reflected in the claims below, the disclosed aspects are less than all the features of the single embodiment disclosed above. Therefore, the claims that follow the specific embodiment are hereby expressly incorporated into the specific embodiment, with each claim itself serving as a separate embodiment of the present disclosure.

[0078] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present disclosure. It should be understood that the above description is only a specific embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure should be included in the protection scope of the present disclosure.

Claims

1. A fluorescence lifetime detection device for pulse current excitation, comprising: A central control unit, used to send a trigger signal, wherein the trigger signal includes a first trigger signal, a second trigger signal, and a third trigger signal; The central control unit is provided with a delay device, which is used to adjust the time difference between the first trigger signal and the second trigger signal; A pulse generator, used for generating a pulse current under the action of a first trigger signal, wherein the pulse current acts on the sample to be tested; A laser, used for emitting a pulse laser with the same frequency as the pulse current under the action of a second trigger signal, wherein the laser is a short-pulse laser with adjustable frequency; A data acquisition unit, used to irradiate the sample to be tested after processing the pulse laser, collect the sample fluorescence generated by the sample to be tested before and after being acted upon by the pulse current, and convert the sample fluorescence into an electrical signal of sample fluorescence intensity; and The data processing and imaging unit is used to process the sample fluorescence intensity electrical signal to obtain the sample fluorescence lifetime image.

2. The fluorescence lifetime detection device according to claim 1, wherein: The data acquisition unit comprises: A microscopic imaging system, used to irradiate the sample to be tested after processing the pulse laser, and collect the sample fluorescence generated by the sample to be tested before and after being acted upon by the pulse current; A photoelectric detector, used to receive the sample fluorescence and convert it into an electrical signal of fluorescence intensity; The counter is used to count and store the fluorescence intensity electrical signal.

3. The fluorescence lifetime detection device according to claim 2, wherein: The microscopic imaging system processes the pulsed laser and then irradiates the sample to be tested. The sample fluorescence generated by the sample to be tested before being acted upon by the pulsed current is the first fluorescence, and the sample fluorescence generated by the sample to be tested after being acted upon by the pulsed current is the second fluorescence.

4. The fluorescence lifetime detection device according to claim 2, wherein: The microscopic imaging system comprises: A convex lens group, capable of converting the pulsed laser into parallel light and emitting the parallel light; A dichroic mirror, used for receiving the parallel light and reflecting it; An objective lens, used for receiving the parallel light reflected by the dichroic mirror, focusing the parallel light and irradiating it onto the sample to be tested, and collecting the sample fluorescence generated by the sample to be tested before and after being acted upon by the pulse current; A filter that can pass light of the same wavelength as the light emitted by the sample to be tested, is used to filter stray light and laser signals, and only passes light of the sample's fluorescence wavelength; The convex lens is used to focus the sample fluorescence transmitted through the filter onto the optical fiber, and transmit the sample fluorescence to the photodetector through the optical fiber.

5. The fluorescence lifetime detection device according to claim 4, wherein: The microscopic imaging system also includes: The eyepiece is used to cooperate with the movable reflector to observe the state of the objective lens focusing on the sample to be tested.

6. The fluorescence lifetime detection device according to claim 1, wherein: The pulse generator can emit pulse currents of different frequencies, sizes and shapes under the action of the first trigger signal.

7. The fluorescence lifetime detection device according to claim 1, wherein: The delay device is also used to control the sending of the third trigger signal to the counter to coordinate the operation of various components.

8. The fluorescence lifetime detection device according to claim 1 or 7, wherein: The delay device is an optical delay device or an electronic board delay device.

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