Circular polarization steady state and transient state detection system

Abstract

The utility model provides a circular polarization steady-state and transient-state detection system, and the system comprises a microscopic imaging assembly which is used for carrying out the microscopic imaging of a to-be-detected sample, determining the position of the sample, and guaranteeing the precise irradiation of laser on the region of the to-be-detected sample; the steady-state circular polarization spectrum detection assembly is used for spectrum detection of steady-state circular polarization light emission of the sample; and the transient circular polarization dynamics detection assembly is used for ultrafast process detection after transient circular polarization light excitation of the sample. The device can detect the steady-state and transient spectrum and service life of a material under the excitation of circularly polarized light, reflect the steady-state and transient properties, including optical properties and carrier dynamic properties, of the material, and is integrated with a microscopic imaging system, so that a to-be-detected sample area can be microscopically imaged to distinguish a material area, and laser is ensured to accurately irradiate the to-be-detected area.

Description

Technical Field

[0001] The utility model provides a circular polarization steady-state and transient-state detection system, belonging to the technical field of spectrum detection. Background Art

[0002] Steady-state circular polarization spectroscopy detection technology detects the material's responsiveness to light of different polarizations by changing the polarization state of the incident light, such as left-handed circularly polarized light or right-handed circularly polarized light, and measures the changes in the material's absorption, transmission, and reflection to light of different polarization states, and reflects the properties of the material's specific polarization state. This technology is widely used in research fields such as chiral compounds, biomaterials, and optoelectronics, and is of great significance to the study of the optical properties of materials.

[0003] Transient circular polarization detection is an important method for studying the transient dynamic process of materials. By exciting the material with a femtosecond laser pulse of a specific polarization state in a short period of time and measuring the material's response to the transient circularly polarized light, we can obtain information such as the material's carrier formation, relaxation, recombination and excited state lifetime. By analyzing the evolution of the measurement signal over time, we can obtain information about the material's carrier dynamics. Transient circular polarization detection technology is widely used in the field of light excitation detection, and is of great significance for understanding the properties of reaction materials and the interaction between light and matter.

[0004] Steady-state circular polarization spectroscopy detects the steady-state properties of reaction materials, including the polarization information and absorption characteristics of the material, while transient circular polarization detection responds to the transient properties of the material and reveals the kinetic behavior of carriers. The two complement each other and jointly reflect the optical properties and kinetic processes of the material, which promotes the understanding of the interaction between light and matter and is also of great significance in materials science and optoelectronics research.

[0005] The reflector (109) is a movable reflector. When microscopic imaging is performed, the reflector (109) moves out of the optical path. The white light source (107) emits illuminating white light, which is reflected by the beam splitter (106) and passes through the beam splitter (103). After being focused by the focusing objective lens (104), the imaging light passes through the focusing objective lens (104), is transmitted through the beam splitter (103) and the beam splitter (106), and is imaged by the CCD camera (108). When circular polarization spectrum detection is performed, the reflector (109) moves into the optical path. , a continuous laser (101) emits laser light, which is converted into circularly polarized light by a depolarizer (102), and the circularly polarized light is reflected by a beam splitter (103), focused by a focusing lens (104) and irradiated onto a sample stage (105), and the photoluminescence passes through the focusing lens (104), is transmitted through the beam splitter (103), is reflected by a reflector (109), the original continuous laser light is filtered out by a filter (1010), and is converted into linearly polarized light by a quarter-wave plate (1011), and is finally collected by a spectrometer (1012).

[0006] The device can only detect the steady-state spectrum of the material under circularly polarized light excitation, reflecting the steady-state properties of the material, but lacks the detection of transient characteristics and cannot reflect the carrier dynamics information of the material. Utility Model Content

[0007] Currently, separate systems are mostly used to study the steady-state and transient states of polarization in materials. Therefore, it is necessary to integrate a set of efficient circular polarization steady-state and transient detection systems.

[0008] The specific technical solution proposed by the utility model is:

[0009] A circular polarization steady-state and transient detection system, comprising: a microscopic imaging component, a steady-state circular polarization spectrum detection component, and a transient circular polarization dynamics detection component;

[0010] The microscopic imaging component is used to perform microscopic imaging of the sample to be tested, determine the sample position, and ensure that the laser is accurately irradiated on the sample area to be tested;

[0011] The steady-state circular polarization spectrum detection component is used for spectrum detection of the steady-state circular polarization photoluminescence of the sample;

[0012] The transient circular polarization dynamics detection component is used to detect ultrafast processes after transient circular polarization light excitation of the sample.

[0013] Among them, the microscopic imaging components include: sample stage, focusing objective lens, white light source, No. 1 beam splitter, and CCD camera;

[0014] The illumination light emitted by the white light source is reflected by the No. 1 beam splitter, collected by the focusing objective lens, and finally irradiated to the sample stage. The reflected imaging light passes through the focusing objective lens, transmits through the No. 1 beam splitter, and is imaged by the CCD camera.

[0015] Among them, the steady-state circular polarization spectrum detection component includes: continuous laser, linear polarizer, No. 1 quarter wave plate, sample stage, focusing objective lens, No. 2 beam splitter, No. 1 reflector, filter, No. 2 quarter wave plate, spectrometer;

[0016] A 488nm continuous laser emits laser light, which is converted into linear polarized light after passing through a linear polarizer. The linear polarized light consists of two components, left-handed circularly polarized light and right-handed circularly polarized light. The linear polarized light is converted into left-handed circularly polarized light or right-handed circularly polarized light after passing through a quarter wave plate No. 1. Left-handed circularly polarized light or right-handed circularly polarized light can be generated by adjusting the angle between the quarter wave plate No. 1 and the linear polarizer. The circularly polarized light is reflected by a second beam splitter and irradiated to the area to be tested on the sample stage through a focusing objective lens. Steady-state circularly polarized photoluminescence generates left-handed circularly polarized light or right-handed circularly polarized light, which passes through a focusing objective lens, is transmitted through a second beam splitter, is reflected by a reflector, and the 488nm laser is filtered out by a filter. The light is converted into linear polarized light after passing through a quarter wave plate No. 2 and is finally collected by a spectrometer.

[0017] Among them, the transient circular polarization dynamics detection components include: femtosecond laser, optical parametric amplifier, No. 2 reflector, linear polarizer, No. 1 quarter wave plate, sample stage, focusing objective, No. 2 beam splitter, No. 1 reflector, filter, No. 2 quarter wave plate, No. 3 reflector, streak camera;

[0018] The femtosecond laser emits 800nm, 1000Hz laser, and the optical parametric amplifier can adjust the light wavelength range to 290nm-2600nm. When the wavelength of the excitation light is lower than or equal to the sample to be tested, it can be used to excite the sample to be tested. For example, adjusting the excitation light wavelength to 400nm can be used for samples with a wavelength range greater than 400nm. It is reflected by the second reflector and passes through the linear polarizer to generate linearly polarized light. The linearly polarized light passes through the first quarter wave plate to generate transient circularly polarized light. Similarly, adjusting the angle between the first quarter wave plate and the linear polarizer can generate transient left-handed circularly polarized light or transient right-handed circularly polarized light, which can selectively excite specific electron spin states. The circularly polarized light is reflected by the second beam splitter and irradiated to the sample stage to be tested through the focusing objective. The transient circularly polarized light excites the sample to generate a specific polarization state signal, which passes through the focusing objective, is transmitted through the second beam splitter and reflected by the first reflector. The excitation laser is filtered out by the filter, converted into linearly polarized light through the second quarter wave plate, reflected by the third reflector, and finally the signal is collected by the streak camera.

[0019] The circular polarization steady-state and transient detection system provided by the utility model is implemented by:

[0020] The device integrates microscopic imaging, spectral detection of steady-state circularly polarized photoluminescence and detection of ultrafast dynamic processes excited by transient circularly polarized light. The second, first and third reflectors are movable reflectors. When the first reflector moves out of the light path, microscopic imaging of the sample area to be tested can be performed. When the second and third reflectors move out of the light path and the first reflector moves into the light path, the steady-state circular polarization spectral detection component works, and spectral detection of steady-state circularly polarized photoluminescence can be performed in the sample area to be tested. When the second, first and third reflectors move into the light path, the transient circular polarization dynamics detection component works, and ultrafast process detection after transient circularly polarized light excitation can be performed in the sample area to be tested.

[0021] The technical effects of the technical solution of the utility model are as follows:

[0022] 1. The utility model aims at circularly polarized light excitation. By setting movable No. 2 reflector, No. 1 reflector and No. 3 reflector, the steady-state and transient spectra and lifetime of the material under circularly polarized light excitation can be detected, and the steady-state and transient properties of the reaction material, including optical properties and carrier dynamics properties, can be detected by integrating a microscopic imaging system, and the material area can be distinguished by microscopic imaging of the sample area to be tested, ensuring that the laser is accurately irradiated on the area to be tested.

[0023] 2. The system of the utility model is simple and flexible. The polarization state of circularly polarized light is realized by a linear polarizer and a quarter-wave plate at a positive or negative 45° angle. The operation is simple and the sample stage area can be further improved. For example, a vacuum low-temperature system or a certain pressure can be applied to the sample stage to detect the spectral characteristics of the material under vacuum, low temperature or stress. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of the prior art;

[0025] Figure 2 This is a schematic diagram of the structure of the circular polarization steady-state and transient detection system of the utility model;

[0026] Figure 3 This is a schematic diagram of the structure of the microscopic imaging component of the utility model;

[0027] Figure 4 This is a schematic diagram of the structure of a steady-state circular polarization spectrum detection component of the utility model;

[0028] Figure 5 This is a schematic diagram of the structure of the transient circular polarization dynamics detection component of the utility model. DETAILED DESCRIPTION

[0029] The present invention is further described below with reference to the accompanying drawings and specific examples:

[0030] like Figure 2 As shown, the circular polarization steady-state and transient detection system of the utility model comprises: a microscopic imaging component, a steady-state circular polarization spectrum detection component, and a transient circular polarization dynamics detection component;

[0031] The microscopic imaging component is used to perform microscopic imaging of the sample to be tested, determine the sample position, and ensure that the laser is accurately irradiated on the sample area to be tested;

[0032] The steady-state circular polarization spectrum detection component is used for spectrum detection of the steady-state circular polarization photoluminescence of the sample to be tested;

[0033] The transient circular polarization dynamics detection component is used to detect the ultrafast process after the transient circular polarization light excitation of the sample to be tested;

[0034] The second reflector 4, the first reflector 10 and the third reflector 16 are movable reflectors;

[0035] The microscopic imaging assembly includes: a sample stage 7, a focusing objective lens 8, a white light source 11, a beam splitter No. 12, and a CCD camera 13;

[0036] The steady-state circular polarization spectrum detection component includes: a continuous laser 1, a linear polarizer 5, a first quarter wave plate 6, a sample stage 7, a focusing lens 8, a second beam splitter 9, a first reflector 10, a filter 14, a second quarter wave plate 15, and a spectrometer 18;

[0037] The transient circular polarization dynamics detection component includes: a femtosecond laser 2, an optical parametric amplifier 3, a second reflector 4, a linear polarizer 5, a first quarter-wave plate 6, a sample stage 7, a focusing objective lens 8, a second beam splitter 9, a first reflector 10, a filter 14, a second quarter-wave plate 15, a third reflector 16, and a streak camera 17.

[0038] Before detection, the sample is first imaged microscopically to determine the sample position, such as Figure 3 As shown, when the No. 1 reflector 10 moves out of the light path, the sample stage 7, the focusing objective lens 8, the No. 1 beam splitter 12, and the CCD camera 13 are in a straight line; the white light source 11 emits illumination light which is reflected by the No. 1 beam splitter 12 and then collected by the focusing objective lens 8, and finally irradiates the sample stage 7, and the reflected imaging light passes through the focusing objective lens 8, is transmitted through the No. 1 beam splitter 12, and is imaged by the CCD camera 13.

[0039] When detecting steady-state circular polarization spectra, Figure 4 As shown, the second reflector 4 and the third reflector 16 are moved out of the light path, the first reflector 10 is moved into the light path, the continuous laser 1, the linear polarizer 5, the first quarter wave plate 6, the second beam splitter 9 are in a straight line, the first reflector 10, the filter 14, the second quarter wave plate 15, and the spectrometer 18 are in a straight line; the 488nm continuous laser 1 emits laser light, which is converted into linear polarized light through the linear polarizer 5. This linear polarized light consists of two components, left-handed circularly polarized light and right-handed circularly polarized light. The first quarter wave plate 6 and the linear polarizer 5 are adjusted to be positive or negative 45 degrees, so The linearly polarized light generates left-handed circularly polarized light or right-handed circularly polarized light after passing through the first quarter wave plate 6. The circularly polarized light is reflected by the second beam splitter 9 and irradiated to the sample area to be tested on the sample stage 7 through the focusing objective lens 8. The steady-state circularly polarized photoluminescence generates left-handed circularly polarized light or right-handed circularly polarized light, which passes through the second beam splitter 9 through the focusing objective lens 8 and is reflected by the first reflector 10. The filter 14 uses a 488nm long wave pass, and the 488nm laser is filtered out by the filter 14. The light is converted into linearly polarized light after passing through the second quarter wave plate 15 and finally collected by the spectrometer 18.

[0040] When detecting transient circular polarization dynamics, such as Figure 5As shown, the second reflector 4, the first reflector 10 and the third reflector 16 are all moved into the optical path, and the femtosecond laser 2, the optical parametric amplifier 3 and the streak camera 17 are used as the excitation and collection systems respectively; the femtosecond laser 2 emits a laser with a frequency of 800nm ​​and 1000Hz, and the optical parametric amplifier 3 can adjust the light wavelength range to 290nm-2600nm. When the wavelength of the excitation light is lower than or equal to the sample to be tested, it can be used to excite the sample to be tested. For example, adjusting the wavelength of the excitation light to 400nm can be used for samples with a wavelength range greater than 400nm. The laser is reflected by the second reflector 4 and generates linear polarized light through the linear polarizer 5. Similarly, the linear polarizer 5 and the first quarter wave plate 6 are at a positive or negative 45°. The linearly polarized light generates transient circularly polarized light through the first quarter wave plate 6. By adjusting the angle between the first quarter wave plate 6 and the linear polarizer 5, transient left-handed circularly polarized light or transient right-handed circularly polarized light can be generated, which can selectively excite a specific electron spin state. The circularly polarized light is reflected by the second beam splitter 9 and irradiated to the sample area to be tested on the sample stage 7 through the focusing objective lens 8. The circularly polarized light excites the sample to generate a specific polarization state signal, which passes through the focusing objective lens 8, is transmitted through the second beam splitter 9 and reflected by the first reflector 10. The filter 14 is selected to filter out the 400nm excitation laser, and then is converted into linearly polarized light through the second quarter wave plate 15, reflected by the third reflector 16, and finally the signal is collected by the streak camera 17.

Claims

1. A circular polarization steady-state and transient detection system, characterized in that: include: Microscopic imaging component, steady-state circular polarization spectrum detection component, transient circular polarization dynamics detection component; The microscopic imaging component is used to perform microscopic imaging of the sample to be tested, determine the sample position, and ensure that the laser is accurately irradiated on the sample area to be tested; The steady-state circular polarization spectrum detection component is used for spectrum detection of the steady-state circular polarization photoluminescence of the sample; The transient circular polarization dynamics detection component is used to detect ultrafast processes after transient circular polarization light excitation of the sample.

2. A circular polarization steady-state and transient detection system according to claim 1, characterized in that: The microscopic imaging assembly comprises: a white light source (11), a first beam splitter (12), a focusing objective lens (8), a sample stage (7) and a CCD camera (13); The illumination light emitted by the white light source (11) is reflected by the first beam splitter (12), collected by the focusing objective lens (8), and finally irradiated to the sample stage (7). The reflected imaging light passes through the focusing objective lens (8), is transmitted through the first beam splitter (12), and is imaged by the CCD camera (13).

3. A circular polarization steady-state and transient detection system according to claim 1, characterized in that: The steady-state circular polarization spectrum detection assembly comprises: a continuous laser (1), a linear polarizer (5), a first quarter wave plate (6), a second beam splitter (9), a focusing objective lens (8), a sample stage (7), a first reflector (10), a filter (14), a second quarter wave plate (15), and a spectrometer (18); A continuous laser (1) emits a 488nm laser, which is converted into linear polarized light through a linear polarizer (5). The linear polarized light consists of two components, left-handed circularly polarized light and right-handed circularly polarized light. The linear polarized light is converted into left-handed circularly polarized light or right-handed circularly polarized light through a first quarter wave plate (6). The angle between the first quarter wave plate (6) and the linear polarizer (5) can generate left-handed circularly polarized light or right-handed circularly polarized light. The circularly polarized light is reflected by a second beam splitter (9) and irradiated to a test area of ​​a sample stage (7) through a focusing objective lens (8). Steady-state circularly polarized photoluminescence generates left-handed circularly polarized light or right-handed circularly polarized light. The light is transmitted through a second beam splitter (9) through a focusing objective lens (8), reflected by a first reflector (10), filtered out by a filter (14) to remove the 488nm laser, converted into linear polarized light through a second quarter wave plate (15), and finally collected by a spectrometer (18).

4. A circular polarization steady-state and transient detection system according to claim 1, characterized in that: The transient circular polarization dynamics detection component comprises: a femtosecond laser (2), an optical parametric amplifier (3), a second reflector (4), a linear polarizer (5), a first quarter wave plate (6), a sample stage (7), a focusing objective lens (8), a second beam splitter (9), a first reflector (10), a filter (14), a second quarter wave plate (15), a third reflector (16), and a streak camera (17); The femtosecond laser (2) emits a laser of 800 nm and 1000 Hz. The optical parametric amplifier (3) adjusts the wavelength of the light to a range of 290 nm to 2600 nm. When the wavelength of the excitation light is lower than or equal to that of the sample to be tested, it is used to excite the sample to be tested, and is reflected by the second reflector (4). The linear polarized light is passed through the linear polarizer (5) to generate linear polarized light. The linear polarized light is passed through the first quarter wave plate (6) to generate transient circular polarized light. Similarly, by adjusting the angle between the first quarter wave plate (6) and the linear polarizer (5), transient left-handed circularly polarized light or left-handed circularly polarized light can be generated. Transient right-handed circularly polarized light can selectively excite the electron spin state. The circularly polarized light is reflected by the second beam splitter (9) and irradiated to the test area of ​​the sample stage (7) through the focusing objective lens (8). The transient circularly polarized light excites the sample to generate a polarization state signal that passes through the focusing objective lens (8), is transmitted through the second beam splitter (9) and reflected by the first reflector (10), and the excitation laser is filtered out by the filter (14), converted into linearly polarized light through the second quarter-wave plate (15), reflected by the third reflector (16), and finally the signal is collected by the streak camera (17).

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