Microscopic light current system

Abstract

The utility model provides a microscopic photocurrent system, comprising a light source used for emitting laser; the light path switching module comprises a reflecting mirror capable of moving on a laser light path; the objective lens and the camera are located on a visible light path after the sample is excited and located on the two sides of the light path switching module respectively; the reflecting mirror can move to a visible light blocking light path and reflects the laser to the sample; the reflector can move to leave the visible light path, so that the camera is imaged. When the reflecting mirror moves to block a visible light path, the reflecting mirror reflects the broadband laser and focuses the broadband laser on the sample through the objective lens, so that the excited light current of the sample can be detected; and when the reflector moves to leave the visible light path, the visible light is subjected to microscopic imaging through the objective lens and the camera. Therefore, the function switching of sample photocurrent detection and visible light on sample microscopic imaging can be realized only by changing the position of the reflector. Compared with a dichroscope suitable for a narrow wave band, the dichroscope provided by the utility model can effectively reduce the cost investment and significantly reduce the experiment and production cost.

Description

Technical Field

[0001] The utility model relates to the technical field of optical path transmission in microscopic imaging, and in particular to a microscopic photocurrent system. Background Art

[0002] Photocurrent refers to the current signal generated when a material is excited by light irradiation, which is the basic principle of a photodetector. Studying the photocurrent response of new micro-nano optoelectronic functional materials can not only study the physical mechanism of the interaction between light and matter (for example, studying the photocurrent generation mechanism related to the properties of light such as spin, polarization, and angular momentum is the forefront of condensed matter optics), but also lay a research foundation for the development of new miniaturized on-chip integrable optoelectronic devices. Materials with micro-nano dimensions need to be observed with the aid of a microscopic system to determine the laser excitation area. And the galvanometric scanner is used to change the position of the laser focus on the sample, or the high-precision electric two-dimensional displacement stage is used to change the position of the excited sample to realize the in-plane photocurrent imaging of the sample.

[0003] The research method of visible-near infrared band photocurrent response mostly adopts confocal microscopic laser optical path excitation, that is, the material is imaged with visible light, and electrodes are connected to the material to measure the photocurrent signal of the laser-excited material. For the optical path system involving the coaxial transmission of visible light and laser through the objective lens, in practice, a beam splitting prism, a beam splitter, a dichroic mirror, etc. are used to achieve the coaxial transmission of visible light and lasers of different bands through transmission and reflection.

[0004] In the prior art, a dichroic mirror is often used when dealing with the coaxial transmission of light of different bands. For example, the Chinese patent CN103604787B authorized and announced on March 23, 2016, which relates to a laser scanning phase microscopic imaging method and system, requires the emitted laser to be reflected by the dichroic mirror to the sample, and then the excited fluorescence is transmitted through the dichroic mirror. The coaxial transmission of visible light and laser in the prior art also adopts this means to achieve.

[0005] However, in the actual use process, the dichroic mirror has a limitation in the use band. The dichroic mirror usually has a narrow applicable band. When wide-spectrum laser excitation is required, multiple-band dichroic mirrors are needed; when the bands to be transmitted and reflected are far apart, such as applying a dichroic mirror to visible light and mid-infrared band, the available dichroic mirror products are scarce and expensive. Summary of the Utility Model

[0006] The purpose of the utility model is to provide a microscopic photocurrent system, which can replace the traditional dichroic mirror and solve the problem of coaxial transmission of visible light and mid-infrared band laser;

[0007] The present utility model provides a microscopic optoelectronic current system, comprising: a light source for emitting laser light; an optical path switching module including a mirror movable on the laser optical path; an objective lens and a camera located on the visible light optical path after exciting the sample and on both sides of the optical path switching module respectively; the mirror can be moved to block the visible light optical path and reflect the laser light to the sample; the mirror can be moved away from the visible light optical path to enable the camera to image.

[0008] Further, the light source is a laser.

[0009] Further, the optical path switching module includes a box body, and a first opening is provided on the box body, and the laser light enters the box body from the first opening.

[0010] Further, a third opening and a fourth opening are provided on the box body, and the visible light enters the box body from the third opening and exits the box body from the fourth opening.

[0011] Further, when the mirror moves to block the visible light optical path, the laser light exits the box body from the third opening.

[0012] Further, a second opening is provided on the box body, and when the mirror moves away from the visible light optical path, the laser light exits the box body from the second opening.

[0013] Further, the second opening is provided on a side of the third opening away from the light source.

[0014] Further, the objective lens is provided on a side of the box body close to the third opening outside the box body, and the camera is provided on a side of the box body close to the fourth opening outside the box body.

[0015] Further, a tube lens and a filter are provided between the camera and the fourth opening, and a collimating lens is provided between the light source and the first opening.

[0016] Further, the mirror surface of the mirror is inclined to the laser optical path.

[0017] The technical solution of the present utility model switches the laser optical path through a movable mirror. When the mirror moves to block the visible light optical path, the mirror reflects the broadband laser light and focuses it on the sample through the objective lens, and the optoelectronic current excited by the sample can be detected; when the mirror moves away from the visible light optical path, the visible light passes through the objective lens and the camera for microscopic imaging. Therefore, the present utility model does not need to replace optical elements multiple times, and only needs to change the position of the mirror to realize the function switching between detecting the optoelectronic current of the sample and microscopic imaging of the sample by visible light; compared with a dichroic mirror with a relatively narrow applicable wavelength band, the present utility model can effectively reduce the cost investment and significantly reduce the experimental and production costs. Description of the Drawings

[0018] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0019] Figure 1 Schematic diagram of the mirror of the present invention moving to block the visible light optical path;

[0020] Figure 2 Schematic diagram of the mirror of the present invention moving away from the visible light optical path;

[0021] Explanation of the reference numerals in the drawings:

[0022] 1 - Camera, 2 - Filter, 3 - Tube lens, 4 - Mirror, 5 - Box, 501 - First opening, 502 - Second opening, 503 - Third opening, 504 - Fourth opening, 6 - Laser, 7 - Objective lens, 8 - Sample, 9 - Collimating lens. Specific embodiments

[0023] The following will clearly and completely describe the technical solutions of the present invention in combination with the embodiments. Obviously, the described embodiments are some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

[0024] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0025] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present utility model, "a plurality of" means two or more, unless otherwise specifically defined. In addition, the terms "mounted", "connected" and "coupled" should be construed in a broad sense. For example, it may be a fixed connection, a detachable connection or an integral connection; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0026] Embodiment 1

[0027] As Figure 1 - Figure 2 shown, the present utility model provides a microscopic photocurrent system, comprising: a light source for emitting laser light; an optical path switching module including a mirror 4 movable on the laser optical path; an objective lens 7 and a camera 1 located on the visible light optical path after exciting a sample 8 and respectively on both sides of the optical path switching module; the mirror 4 can be moved to block the visible light optical path and reflect the laser light to the sample 8; the mirror 4 can be moved away from the visible light optical path to enable the camera 1 to image.

[0028] Specifically, the optical path switching module is arranged on one side of the light source, the camera 1 and the objective lens 7 are respectively arranged on both sides of the optical path switching module, and the camera 1 and the objective lens 7 are respectively located on both sides of the laser optical path. The sample 8 is placed on the far side of the objective lens 7 with respect to the optical path switching module.

[0029] The mirror 4 is a metal mirror 4 (or a triangular prism coated with metal), with a reflective film on its surface, for reflecting and regulating the transmission path of the laser light, and is controlled to move by a movement control mechanism, and the movement path is along the laser optical path. The metal mirror 4 has a relatively wide reflection bandwidth, almost covering all optical frequency ranges, which enables it to effectively reflect light at various wavelengths. In addition, the metal mirror 4 has a low sensitivity to the incident angle, which increases its applicability in various optical system configurations.

[0030] The moving control mechanism is, for example, a linear drive mechanism. Specifically, for example, two hydraulic telescopic rods are respectively connected to both sides of the back surface (the side that does not reflect laser) of the mirror 4 (both sides of the laser optical path and the visible light optical path); or, for example, a motor-screw structure and the side surface of the mirror 4 is connected to the screw nut. Both can achieve the control of the movement of the mirror 4 along the laser optical path. In addition, the connection between the linear drive mechanism and the mirror 4 can also be designed as a rotatable connection method to adjust the reflection angle of the mirror 4. For example, a reduction motor is connected to the outside of the screw nut, and then the output end of the motor is connected to the mirror 4, so that the rotation of the mirror 4 can be controlled by the rotation of this reduction motor. Such a linear drive mechanism and a rotation control mechanism should be easy to implement for those skilled in the art and will not be elaborated further.

[0031] When the mirror 4 moves between the objective lens 7 and the camera 1, that is, on the visible light path, as Figure 1 shown, the mid-infrared laser is reflected and focused to excite the sample 8. At this time, the visible light is blocked, and the detection of the photocurrent of the sample can be achieved through the electrode connected to the sample.

[0032] Then move or rotate the position of the mirror 4 so that the mirror 4 is placed outside the visible light path, as Figure 2 shown. At this time, the mirror 4 leaves the visible light path, and the visible light then passes through the objective lens 7 and the optical path switching module to the camera 1, and the camera 1 can achieve the purpose of microscopically imaging the sample.

[0033] Embodiment 2

[0034] The light source is the laser 6. The mirror surface of the mirror 4 is inclined with respect to the laser optical path.

[0035] Specifically, emitting laser through the laser 6 is prior art in the art and is common in usage scenarios such as laboratories, and its structural principle will not be elaborated further. The inclined structure of the mirror 4 is the same as the inclined setting of the dichroic mirror, and is used to reflect the laser towards the objective lens 7 and focus it on the sample 8 to excite the sample 8. By precisely controlling the position of the metal mirror 4 through movement or rotation, the coaxial transmission of lasers and visible light in different bands is achieved.

[0036] Embodiment 3

[0037] The optical path switching module includes a box body 5, on which there is a first opening 501, and laser light enters the box body 5 through the first opening 501. There are a third opening 503 and a fourth opening 504 on the box body 5. Visible light enters the box body 5 through the third opening 503 and exits the box body 5 through the fourth opening 504. When the mirror 4 moves to block the visible light optical path, the laser light exits the box body 5 through the third opening 503. There is a second opening 502 on the box body 5. When the mirror 4 moves away from the visible light optical path, the laser light exits the box body 5 through the second opening 502. The second opening 502 is arranged on the side of the third opening 503 away from the light source. The objective lens 7 is arranged on the side of the box body 5 outside and close to the third opening 503, and the camera 1 is arranged on the side of the box body 5 outside and close to the fourth opening 504. There are a tube lens 3 and a filter 2 between the camera 1 and the fourth opening 504, and there is a collimating lens 9 between the light source and the first opening 501.

[0038] Specifically, the box body 5 is a cuboid structure, hollow inside for placing the moving mirror 4, and for the laser optical path and the visible light optical path to pass through.

[0039] The laser light is emitted from the laser 6, enters the box body 5 through the collimating lens 9 from the first opening 501, and exits the box body 5 through the third opening 503 or the second opening 502. The visible light reflected by the sample 8 enters the box body 5 through the third opening 503 and exits the box body 5 through the fourth opening 504 after the mirror 4 moves away.

[0040] Specifically, when the mirror 4 moves forward to the visible light optical path position, the laser light is reflected by the mirror 4 and exits through the third opening 503 to the objective lens 7 and is focused on the sample 8 to excite the sample 8. At this time, the mirror 4 blocks the visible light optical path to achieve beam combination. At this time, the photocurrent of the sample can be detected through the electrode connected to the sample.

[0041] When the mirror 4 moves backward to the position away from the visible light optical path, the visible light reflected by the sample 8 enters the third opening 503 through the objective lens 7 and exits through the fourth opening 504, passes through the tube lens 3 and the emission filter 2 to the CCD camera 1. At this time, the camera 1 performs microscopic imaging on the sample through the visible light. And the laser light is reflected by the mirror 4 and exits smoothly through the second opening 502, which can be used to measure the power of the infrared laser; and the box body 5 can block the laser light reflected outside the box body 5.

[0042] The working mode and principle of the present utility model:

[0043] When the mirror 4 moves to block the visible light optical path, the mirror 4 reflects the broadband laser and focuses it onto the sample 8 through the third opening 503 and the objective lens 7, and the photocurrent excited by the sample can be detected; after the sample 8 is excited, the visible light cannot pass through the mirror 4. When the mirror 4 moves away from the visible light optical path, the visible light passes through the objective lens 7, the third opening 503, the fourth opening 504, the tube lens 3, the emission filter 2 and the camera 1, and the camera 1 can use the visible light to perform microscopic imaging on the sample (visible light microscopic imaging, not affected by whether the laser excites the sample); the laser passes through the second opening 502 and exits the box body 5, and the power of the infrared laser can be measured.

[0044] The low-cost solution of the present utility model by moving the mirror 4 to replace the dichroic mirror solves the coaxial problem of visible light and mid-infrared band lasers. There is no need to replace components multiple times. Only by changing the position of the mirror 4, the function switching between ultraviolet-mid-infrared band broadband laser excitation for detecting the photocurrent of the sample and visible light band microscopic imaging can be realized. The structure is simple and the operation is convenient.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present utility model and are not intended to limit them; although the present utility model has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present utility model.

Claims

1. A microscopic photocurrent system, characterized in that: include: A light source for emitting laser light; An optical path switching module, including a reflector that can move on the laser optical path; The objective lens and the camera are located on the optical path of the visible light after the sample is excited, and are respectively located on both sides of the optical path switching module; The reflector can be moved to block the visible light path and reflect the laser to the sample; The mirror can be moved away from the visible light path to enable the camera to form an image.

2. The microscopic photocurrent system according to claim 1, characterized in that: The light source is a laser.

3. The microscopic photocurrent system according to claim 1, characterized in that: The optical path switching module comprises a box body, the box body is provided with a first opening, and the laser is emitted into the box body from the first opening.

4. The microscopic photocurrent system according to claim 3, characterized in that: The box body is provided with a third opening and a fourth opening, and visible light enters the box body from the third opening and exits the box body from the fourth opening.

5. The microscopic photocurrent system according to claim 4, characterized in that: When the reflector moves to block the visible light path, the laser is emitted from the box through the third opening.

6. The microscopic photocurrent system according to claim 5, characterized in that: The box body is provided with a second opening, and when the reflector moves away from the visible light path, the laser is emitted out of the box body from the second opening.

7. The microscopic photocurrent system according to claim 6, characterized in that: The second opening is disposed on a side of the third opening away from the light source.

8. The microscopic photocurrent system according to claim 5, characterized in that: The objective lens is arranged on a side of the outside of the box close to the third opening, and the camera is arranged on a side of the outside of the box close to the fourth opening.

9. The microscopic photocurrent system according to claim 8, characterized in that: A tube lens and a filter are arranged between the camera and the fourth opening, and a collimating lens is arranged between the light source and the first opening.

10. The microscopic photocurrent system according to claim 1, characterized in that: The mirror surface of the reflector is arranged to be inclined with respect to the laser light path.

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