Angle resolution spectral measurement device based on linear array CCD (Charge Coupled Device)

Abstract

The utility model discloses an angle resolution spectral measurement device based on a linear array CCD, and relates to the field of imaging. Comprising an incident light path, a real space imaging reflection light path and a k space imaging reflection light path. The incident light path provides a light source for the device and focuses on a sample to-be-detected area to excite a sample; the real space imaging reflection light path is used for imaging a sample in a light source excitation area; and the k-space imaging reflection light path is used for measuring optical information of the sample in the momentum space. The Labview upper computer controls the displacement table and the spectrograph to achieve the synergistic effect, so that automatic collection of spectrum data information of the whole K space is achieved, and a practical and efficient spectrum detection technology is provided for research of microcavity excitons and polaritons.

Description

Technical Field

[0001] The utility model relates to the field of imaging, in particular to an angle-resolved spectrum measuring device based on a linear array CCD. Background Art

[0002] Microcavity exciton polaritons are an important research direction in the field of light-matter interaction. They are used to realize a series of optoelectronic devices with high speed, low consumption and coherence properties, such as laser light sources, switches and logic processors. They are of great significance both for the development needs of physics theory and for practical applications. In recent years, the development of microcavity processing technology has further promoted the development of this field, especially the research on the strong coupling of light and semiconductor excitons, which has achieved amazing results. Experiments and theories are advancing hand in hand and driving each other.

[0003] Angular-resolved spectroscopy has been widely used in the field of light-matter interaction research due to its high precision, high resolution, and non-contact capabilities. Angular-resolved spectroscopy can be used to study the energy-momentum dispersion behavior of exciton polaritons, clearly display the upper and lower energy branches of exciton polaritons, and observe their energy level splitting and anti-cross dispersion. Therefore, angular-resolved spectroscopy has become a necessary optical characterization method in the field of exciton polaritons. The currently commonly used area array CCD can directly obtain the dispersion relationship diagram of the K space within the entire collectible range, but high-precision area array CCDs for some specific bands are not easy to obtain and are expensive, especially for electromagnetic waves in infrared, near-infrared and ultraviolet bands. The measurement of angular-resolved spectroscopy is greatly restricted. Therefore, how to use a simpler linear array CCD to achieve the same optical characterization results is the focus of the present invention. Utility Model Content

[0004] The utility model aims to provide an angular resolution spectrum measurement device based on a linear array CCD, which effectively solves the dependence on high-precision area array CCD in angular resolution spectrum testing, greatly reduces the cost of the testing device, and improves the testing accuracy and efficiency.

[0005] The utility model comprises an incident light path and a reflected light path, wherein the reflected light path is divided into a real space imaging reflected light path for determining the sample test position and a k-space imaging reflected light path for collecting sample angle-resolved spectral data;

[0006] The incident light path includes an incident light source, a first plane reflector, a beam splitter, an objective lens and a sample stage in sequence; the sample stage, the objective lens and the beam splitter are also components of the reflected light path; the light emitted by the light source enters the objective lens after being reflected by the first plane reflector and the beam splitter, and the sample in the sample stage is placed at the focus of the objective lens, so that the light emitted by the light source is focused on the sample to be tested area to stimulate the spectral signal of the sample; the first plane reflector and the beam splitter are both at a 45° angle to the collimated light path;

[0007] The real-space imaging reflective light path comprises a sample stage, an objective lens, a beam splitter, a removable plane reflector, a second plane reflector, a third convex lens and a camera which are arranged in sequence; the beam splitter, the removable plane reflector and the second plane reflector are all at an angle of 45° to the collimated light path; the reflected light beam of the sample in the sample stage passes through the objective lens and the beam splitter in sequence, enters the third convex lens after being reflected by the removable plane reflector and the second plane reflector, and enters the camera for imaging after passing through the third convex lens, so as to be used for sample imaging observation;

[0008] Removing or flipping the removable plane reflector in the real-space imaging reflective light path, and switching the reflective light path to a k-space imaging reflective light path;

[0009] The k-space imaging reflection light path comprises a sample stage, an objective lens, a beam splitter, a first convex lens, a second convex lens, a translation stage, and a spectrometer, which are arranged in sequence; the excitation light of the sample in the sample stage passes through the objective lens, the beam splitter, the first convex lens, and the second convex lens in sequence and is finally focused on the incident slit of the spectrometer, and a part of the k-space spectrum in the reflected light spot of the sample to be measured is obtained through the linear array CCD of the spectrometer; the second convex lens is placed on the translation stage, and the translation stage and the spectrometer are both connected to a computer; the translation stage is perpendicular to the linear array CCD direction of the spectrometer, and is used to measure the optical information of the sample in the momentum space; the translation stage is used to realize the complete k-space spectrum data collection of different regions; the beam splitter is at a 45° angle to the collimated light path; the optical path between the objective lens and the first convex lens is equal to the focal length of the first lens. The distance f1, the optical path between the objective lens and the second convex lens is equal to the focal length f2 of the second lens, the focus of the second convex lens falls on the back focal plane of the first convex lens, the optical path between the first convex lens and the second convex lens is equal to the sum of the focal lengths of the two lenses f1+f2, and the linear array CCD of the spectrometer is on the back focal plane of the second convex lens; the translation stage perpendicular to the direction of the linear array CCD scans the second convex lens perpendicular to the direction of the linear array CCD under the control of the Labview host computer, so that the spectral information of different one-dimensional areas of the reflected light spot is focused on the slit of the spectrometer, and the internal linear array CCD collects the sample spectral signal and forms an image. After that, the collected spectral images are spliced ​​using the Combine function provided by Matlab to realize the Fourier information acquisition of the complete K space.

[0010] The sample stage is used to control different conditions of the sample such as sample position, temperature, magnetic field, etc. The sample stage includes but is not limited to a translation stage, a low-temperature ARS system, a strong magnetic field AttoCube system, etc.

[0011] The objective lens is used as a Fourier transform device to focus light emitted from the sample at different angles at different positions of the back focal plane to form a conjugate plane of the sample k space.

[0012] The first convex lens and the third convex lens are used to perform Fourier transform on the sample k-space again, so as to form a conjugate surface of the sample real space. The first convex lens and the third convex lens are simultaneously confocal with the objective lens.

[0013] The second convex lens is used to perform Fourier transform again on the real space of the sample formed by the first convex lens, so that the spectrometer can collect the k-space spectrum information of the sample. The first convex lens and the second convex lens are confocal, and the spectrometer incident slit is placed at the back focal plane of the second convex lens.

[0014] The removable plane reflector can be flexibly flipped up. When it is necessary to image the sample in real space to determine the sample detection area, the removable plane reflector is placed in the light path so that the light path passes through the third convex lens and is incident on the visible light camera for imaging; when it is necessary to collect the k-space spectrum of the sample, the removable plane reflector is flipped up so that the light path passes directly to the first convex lens and the second convex lens to be collected by the spectrometer.

[0015] The linear array CCD equipped in the spectrometer can only collect spectral data in a one-dimensional area.

[0016] The Labview host computer is used to control the spectrometer to automatically collect spectra after the translation stage moves a certain distance, so as to realize the automated collection of the complete k-space spectrum of the sample. The control program is a program file attached to the device and only needs to be called. The program files available on the device include LABVIEW, python, and matlab.

[0017] Compared with the prior art, the utility model has the following advantages:

[0018] 1. The utility model realizes the collection of complete K-space spectral data in different areas by adding a translation stage in the reflected light path, and controls the translation stage and the spectrometer through the Labview host computer to realize the effect of automatic collection, thereby reducing cumbersome manual operation steps and improving test efficiency.

[0019] 2. The utility model uses a relatively low-cost linear array CCD to achieve the collection effect of an area array CCD. Due to the high-precision characteristics of the linear array CCD, the spectral data collection effect for a single point area is better than that of the area array CCD.

[0020] 3. The real-space imaging reflection light path introduced by the utility model can effectively observe and locate the test area of ​​the sample, thereby improving the test accuracy and efficiency.

[0021] 4. The optical path of the utility model is simple and easy to test. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the device of the utility model.

[0023] The marks in the figure are: sample stage 1, objective lens 2, beam splitter 3, removable plane mirror 4, first convex lens 5, second convex lens 6, linear array CCD spectrometer 7, computer 8, one-dimensional translation stage 9 perpendicular to the direction of the linear array CCD, incident light source 10, camera 11, third convex lens 12, second plane mirror 13, first plane mirror 14.

[0024] Figure 2 The near-infrared angle-resolved spectrum of a Bragg reflector is measured using an angle-resolved spectrum measurement device based on a linear array CCD.

[0025] Figure 3 This is an example of local information of the near-infrared angle-resolved spectrum of a Bragg reflector. The horizontal axis is the wavelength (nm) and the vertical axis is the relative intensity (au). DETAILED DESCRIPTION

[0026] The technical solution of the utility model is described in detail below in conjunction with specific implementation plans.

[0027] like Figure 1 As shown, the linear array CCD angle-resolved spectral measurement system of the present invention includes an incident light path, a sample stage 1 which is on the same horizontal line and aligned with the incident light path, an objective lens 2, a beam splitter 3, a reflection light path for angle-resolved spectral information, and a reflection light path for imaging.

[0028] The incident light path includes an incident light source 10, a first plane reflector 14, and a beam splitter 3 placed in sequence. The plane mirror projects the incident light onto the sample on the sample stage. Both the first plane reflector 14 and the beam splitter need to be at a 45° angle to the collimated light path. The sample stage 1, the objective lens 2, and the beam splitter 3 are also components of the reflected light path. The incident light source 10 provides a light beam, which passes through the first plane mirror 14 and the beam splitter 3, and the light spot is focused on the sample on the sample stage. The sample stage can be modulated in multiple dimensions to move the sample to the correct imaging position.

[0029] The reflected light path consists of two parts: the real space imaging reflected light path and the k-space imaging;

[0030] The real-space imaging reflective light path includes a sample stage 1, an objective lens 2, a beam splitter 3, a removable plane reflector 4, a second plane reflector 13, a third convex lens 12 and a camera 11 which are arranged in sequence; the beam splitter 3, the removable plane reflector 4 and the second plane reflector 13 are all at an angle of 45° to the collimated light path; after the reflected light beam passes through the removable plane reflector 4 and the second plane reflector 13, it enters the camera 11 through the third convex lens 12 for sample imaging observation.

[0031] When the removable plane reflector 4 is removed, the real-space imaging reflection light path is immediately switched to the k-space imaging reflection light path, which includes a sample stage 1, an objective lens 2, a beam splitter 3, a first convex lens 5, a second convex lens 6, a one-dimensional displacement stage 9 perpendicular to the direction of the linear array CCD, and a linear array CCD spectrometer 7 arranged in sequence, the one-dimensional displacement stage 9 perpendicular to the direction of the linear array CCD and the linear array CCD spectrometer 7 are connected to a computer 8; at the same time, the beam splitter 3 is at an angle of 45° to the collimated light path; the optical path between the objective lens 2 and the first convex lens 5 is equal to the focal length f1 of the first convex lens 5, the focus of the second convex lens 6 falls on the back focal plane of the first convex lens 5, and the focal length of the second convex lens 6 is f2. Therefore, the optical path between the first convex lens 5 and the second convex lens 6 is equal to the sum of the focal lengths of the two lenses, f1+f2, and the incident slit of the linear array CCD spectrometer 7 is just on the back focal plane of the second convex lens 6; at this time, the image is Fourier transformed through the objective lens 2, the first convex lens 5, and the second convex lens 6, and the k-space spectral information is presented on the back focal plane of the second convex lens 6; the one-dimensional translation stage 9 perpendicular to the direction of the linear array CCD scans the second convex lens 6 perpendicular to the direction of the linear array CCD under the control of the Labview host computer, so that the spectral information of different one-dimensional areas of the reflected light spot is focused on the linear array CCD and collected, and finally the collected spectral images are spliced ​​to realize the Fourier information acquisition of the complete K space.

[0032] Using a halogen lamp as the light source, the angle-resolved spectrum of the near-infrared light reflected by a Bragg reflector with a central wavelength of 1100nm and a bandwidth of 400nm was measured; Figure 1An angle-resolved spectral measurement device is constructed. The light emitted by the light source is reflected by the first plane reflector and the beam splitter and enters the objective lens. The sample in the sample stage is placed at the focus of the objective lens, so that the light emitted by the light source is focused on the sample to be tested area to excite the sample; the reflected light of the sample passes through the objective lens and the beam splitter in turn, enters the third convex lens by the reflection of the removable plane reflector and the second plane reflector, and is finally focused on the visible light camera for real-space imaging. At this time, the best test point of the sample is adjusted according to the imaging; after determining the position of the sample, the removable plane reflector is flipped up, so that the excitation light of the sample passes through the objective lens, the beam splitter, the first convex lens, and the second convex lens in turn, and is finally focused on the incident slit of the spectrometer. The partial k-space spectrum in the reflected light spot of the sample to be tested can be obtained through the linear array CCD, and the second convex lens is placed perpendicular to the linear array CCD. The one-dimensional translation stage is placed on a one-dimensional translation stage, and the translation stage and the spectrometer are connected to a computer. Under the control of the Labview host computer, the second convex lens is scanned perpendicular to the direction of the linear array CCD, so that the spectral information of different one-dimensional areas of the reflected light spot is focused on the linear array CCD and collected. The linear array CCD pixel in this embodiment is 1×1024pix, and the working wavelength is 850-1650nm. Under the control of the LABVIEW host computer, the translation stage moves 0.02mm every time to enable the spectrometer to automatically collect the spectrum. Finally, the collected spectral images are spliced ​​using the Combine program provided by Matalb to realize the spectral collection of the complete K space. The angle-resolved spectrum measurement device based on the linear array CCD is used to measure the near-infrared angle-resolved spectrum of the Bragg reflector. The results are as follows Figure 2 If the above-mentioned automated system is not used for testing, only partial information can be obtained, such as Figure 3 shown. Figure 3 The spectrum diagram is just a line diagram, corresponding to the spectrum data at one angle, which is equivalent to Figure 2 The data corresponding to one angle is intercepted. It is obvious that with the help of the above-mentioned automated system, relatively complete spectral data can be collected.

[0033] The utility model can utilize the linear array CCD to realize the complete collection of the entire K-space spectrum data of the sample, and can obtain the dispersion information of the sample; the system has low cost, simple operation and high automation.

[0034] The above embodiments are only preferred embodiments of the present utility model and cannot be considered to limit the scope of implementation of the present utility model patent; all equivalent changes and improvements made within the scope of the present utility model patent application should still fall within the scope of this patent.

Claims

1. An angle-resolved spectral measurement device based on a linear array CCD, characterized in that: Including incident light path, real space imaging reflection light path, k-space imaging reflection light path; The incident light path comprises: a light source (10), a first plane reflector (14), a beam splitter (3), an objective lens (2), and a sample stage (1) on which a sample is located; light emitted by the light source (10) enters the objective lens (2) after being reflected by the first plane reflector (14) and the beam splitter (3), and the sample in the sample stage (1) is placed at the focus of the objective lens, so that the light emitted by the light source (10) is focused on the sample to be tested area to excite the sample; The real-space imaging reflective light path comprises: a sample stage (1), an objective lens (2), a beam splitter (3), a removable plane reflector (4), a second plane reflector (13), a third convex lens (12) and a visible light camera (11); reflected light from a sample in the sample stage (1) passes through the objective lens (2) and the beam splitter (3) in sequence, enters the third convex lens (12) through reflection from the removable plane reflector (4) and the second plane reflector (13), and finally focuses on the visible light camera (11) for imaging; The k-space imaging reflection light path comprises: a sample stage (1), an objective lens (2), a beam splitter (3), a first convex lens (5), a second convex lens (6), and a spectrometer (7) where a linear array CCD is located; the excitation light of the sample in the sample stage (1) passes through the objective lens (2), the beam splitter (3), the first convex lens (5), and the second convex lens (6) in sequence and is finally focused on the incident slit of the spectrometer (7); a partial k-space spectrum in the reflected light spot of the sample to be measured can be obtained through the linear array CCD; the second convex lens (6) is placed on a one-dimensional displacement stage (9) perpendicular to the direction of the linear array CCD; the displacement stage (9) and the spectrometer (7) are both connected to a computer (8); under the control of a Labview host computer, the second convex lens (6) is scanned perpendicular to the direction of the linear array CCD, so that the spectral information of different one-dimensional regions of the reflected light spot is focused on the linear array CCD and collected; the collected spectral image data is spliced ​​using a Combine function provided by Matlab to realize the Fourier information collection of the complete k-space.

2. The angle-resolved spectroscopy measuring device based on a linear array CCD according to claim 1, characterized in that: The sample stage (1) is used for controlling different conditions of sample position, temperature and magnetic field of the sample, and the sample stage (1) comprises a displacement stage, a low-temperature ARS system and a strong magnetic field AttoCube system.

3. The angle-resolved spectroscopy measuring device based on a linear array CCD according to claim 1, characterized in that: The objective lens (2) serves as a Fourier transform device, and emits light of different angles to the sample, which converges at different positions of the rear focal plane to form a conjugate plane of the sample k space.

4. The angle-resolved spectroscopy measuring device based on a linear array CCD according to claim 1, characterized in that: The first convex lens (5) and the third convex lens (12) are used to perform a Fourier transform on the sample k-space again, thereby forming a sample real space conjugate surface. The first convex lens (5) and the third convex lens (12) need to be confocal with the objective lens (2) at the same time.

5. The angle-resolved spectroscopy measuring device based on a linear array CCD according to claim 1, characterized in that: The second convex lens (6) is used to perform Fourier transform again on the real space of the sample formed by the first convex lens (5), so that the spectrometer (7) can collect the k-space spectrum information of the sample. The first convex lens (5) and the second convex lens (6) are cofocal, and the spectrometer entrance slit is placed at the rear focal plane of the second convex lens (6).

6. The angle-resolved spectroscopy measuring device based on a linear array CCD according to claim 1, characterized in that: The removable plane reflector (4) can be flipped up. When it is necessary to image the real space of the sample to determine the sample detection area, the removable plane reflector (4) is placed in the light path so that the light path passes through the third convex lens (12) and is incident on the visible light camera (11) for imaging; when it is necessary to collect the k-space spectrum of the sample, the removable plane reflector (4) is flipped up so that the light path directly passes through the first convex lens (5) and the second convex lens (6) to be collected by the spectrometer (7).

7. The angle-resolved spectroscopy measuring device based on a linear array CCD according to claim 1, characterized in that: The linear array CCD can only collect spectral data in a one-dimensional area.

8. The angle-resolved spectroscopy measuring device based on a linear array CCD according to claim 1, characterized in that: The Labview host computer is used to control the spectrometer (7) to automatically collect spectra after the translation stage (9) moves a certain distance, so as to realize the automated collection of the complete k-space spectrum of the sample.

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