Optical structure capable of eliminating excitation fluorescence background stray light and fluorescence detection system
By setting through holes and inclined side baffles on the sidewall of the dichroic mirror structure, multiple reflections of the excitation light are achieved, which solves the problem of background interference from the excitation light source in fluorescence detection and improves the signal-to-noise ratio of fluorescence detection and the detection accuracy of the microscope.
Patent Information
- Application Number
- CN202422989014.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-05
- Publication Date
- 2025-11-07
- Estimated Expiration
- 2034-12-05
AI Technical Summary
In existing fluorescence detection methods, background interference from the excitation source severely affects detection sensitivity, causing the fluorescence signal to be submerged and making it difficult to achieve high-precision fluorescence microscopy detection.
Through holes are provided on the side wall of the dichroic mirror structure and equipped with inclined side baffles, so that the excitation light is reflected multiple times at the corner. By designing an extinction channel in the optical structure, the reflection of the excitation light inside the device is reduced, and stray light interference is reduced.
It significantly reduces interference from excitation stray light, improves the signal-to-noise ratio of fluorescence detection, enhances the detection accuracy of fluorescence microscopy, and is low in cost and simple to operate.
Smart Images
Figure CN223526250U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the field of fluorescence detection, specifically to a kind of optical structure and fluorescence detection system capable of eliminating excitation fluorescence background stray light. BACKGROUND
[0002] Fluorescence labeling refers to covalently binding or physically adsorbing some substances capable of emitting fluorescence on a certain group of molecules to be studied, and using its fluorescence characteristics to provide information of the object being studied. Currently, fluorescence labeling has been widely used in molecular and immunodetection fields.
[0003] Detection sensitivity is an important indicator of fluorescence labeling detection. The limiting factor for improving the detection sensitivity of fluorescence labeling is the background interference of excitation light source. Under the condition of background interference of excitation light source, only improving the detection sensitivity of sensor also amplifies the interference signal in the same proportion, so eliminating the background interference introduced by excitation light source is the core problem of improving the detection sensitivity of excitation fluorescence.
[0004] Generally, the brightness of emitted fluorescence is equivalent to one thousandth to one ten-thousandth of the energy of excitation light, which is very weak compared to excitation light. Both of them coexist in the test sample, and the wavelength interval between the excitation spectrum and the emission spectrum of fluorescence is very small (about 15nm-30nm). Therefore, to detect the light signal, the excitation light and the emission light in the fluorescence system must be deeply isolated in the spectrum, and at least the isolation degree should reach OD4 or above to detect the fluorescence signal emitted by the sample. In order to improve the accuracy of fluorescence detection, the isolation degree often needs to be improved to OD5 or above. Moreover, the higher the isolation degree of the filter, the stronger the detection ability of trace fluorescence, and the higher the detection precision of fluorescence microscope. Therefore, it is very important to isolate uncontrollable excitation light stray light in the optical path.
[0005] A typical isolation scheme is shown in Figure 1 When excitation light passes through a 45° dichroic mirror, most of the light is reflected, but some light still penetrates the dichroic mirror filter and reaches the structure containing the dichroic mirror. The reflectivity of the structure surface after dull oxidation treatment is usually between 10% and 20%. The stray light reflected by the structure is reflected downward by the dichroic mirror, and mixed with the main light. Because part of the excitation light with too large angle cannot be filtered by the fluorescence emission sheet, the stray light finally forms interference on the detector, which affects the fluorescence imaging. CONTENT OF THE UTILITY MODEL
[0006] Therefore, the utility model embodiment aims to provide an optical structure and fluorescence detection system capable of eliminating excitation fluorescence background stray light to improve the above problems.
[0007] The utility model embodiment provides an optical structure capable of eliminating excitation fluorescence background stray light, which comprises:
[0008] a structure, having a first side wall as an incident surface and a second side wall opposite to the first side wall, and a notched corner formed outside the second side wall; the second side wall is provided with a through hole for light emission;
[0009] a dichroic mirror accommodated in the structure, configured to receive excitation light incident from the first side wall and output the transmitted excitation light from the through hole of the second side wall;
[0010] a side baffle, obliquely arranged at the notched corner, configured to reflect the excitation light output from the through hole multiple times at the notched corner.
[0011] Preferably, the inner wall of the through hole is provided with light extinction threads.
[0012] Preferably, the notched corner is an L-shaped notched corner, and both ends of the side baffle are arranged on the two sides of the L-shaped notched corner.
[0013] Preferably, the included angle between the side baffle and the outer side of the second side wall is 25°-75°.
[0014] Preferably, the L-shaped notched corner is formed with a chamfer, and the surface is subjected to matte oxidation treatment.
[0015] Preferably, the radius of the chamfer is 0.5-10mm.
[0016] Preferably, the incident surface is provided with a laser sheet.
[0017] Preferably, the reflection times are at least 8 times.
[0018] Preferably, the side surface of the structure close to the receiving surface is further provided with an emission sheet.
[0019] The utility model embodiment further provides a fluorescence detection system, it includes objective lens, pipe mirror, receiving surface and can eliminate excitation fluorescence background stray light's optical structure as above.
[0020] The utility model discloses a through hole is arranged on the side wall of the structure loaded with the dichroic mirror, and the side baffle with the inclination angle is matched, so that the excitation light can be reflected multiple times in the light extinction channel of the notched corner and the side baffle, to avoid the light pollution caused by the reflection of excitation light in the whole equipment. The scheme has the advantages of low cost, easy operation, remarkable effect and the like. BRIEF DESCRIPTION OF DRAWINGS
[0021] In order to more clearly illustrate the technical scheme of the utility model, the following will be briefly introduced the drawing needed to be used in the embodiment, obviously, the drawing in the following description is only some embodiments of the utility model, for the ordinary skilled person in the art, under the premise of not paying the creative labor, still can obtain other drawings according to these drawings.
[0022] Figure 1 It is a structural schematic view of an existing fluorescence detection system.
[0023] Figure 2 It is a structural schematic view of an optical structure capable of eliminating excitation fluorescence background stray light provided by the first embodiment of the utility model.
[0024] Figure 3 It is a structural schematic view of a fluorescence detection system provided by the second embodiment of the utility model. DETAILED DESCRIPTION
[0025] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the utility model.
[0026] Please refer to Figure 2 and Figure 3 The embodiment of the utility model provides an optical structure 100 capable of eliminating excitation fluorescence background stray light, which comprises:
[0027] The structural member 10 has a first side wall 11 as an incident surface and a second side wall 12 opposite to the first side wall 11, and a corner 13 is formed outside the second side wall 12; the second side wall 12 is provided with a through hole 121 for light output.
[0028] In the embodiment, in particular, the inner wall of the through hole 121 is provided with light extinction threads, so that the light extinction effect can be further improved.
[0029] The dichroic mirror 20 is accommodated in the structural member 10, which is configured to receive incident excitation light incident from the first side wall 11 and output the transmitted excitation light from the through hole 121 of the second side wall 12.
[0030] In the embodiment, as shown in Figure 2 The laser sheet 111 is arranged at the first side wall 11, the incident excitation light passes through the laser sheet 111 and reaches the dichroic mirror 20, the dichroic mirror 20 simultaneously reflects and transmits the excitation light, the reflected excitation light enters the objective lens 200 through the third side wall 14, then reaches the fluorescence sample 300 through the objective lens 200, carries the fluorescence sample information after being reflected by the fluorescence sample, and then reaches the receiving surface 500 through the objective lens 200, the structural member 10 and the tube lens 400 in sequence. The transmitted excitation light is output through the through hole 121 of the second side wall 12.
[0031] The side baffle 30 is arranged at the corner 13 and is configured to reflect the excitation light output from the through hole 121 at the corner 13.
[0032] In the embodiment, the excitation light output from the through hole 121 is reflected at the surface of the side baffle 30, and the reflected excitation light is repeatedly reflected outside the corner, so as to achieve the purpose of light extinction.
[0033] Specifically, the corner 13 is an L-shaped corner, both ends of the side baffle 30 are arranged on two arms of the L-shaped corner, and the included angle between the side baffle 30 and the outer side of the second side wall 12 is 25°-75°, preferably 34°. The L-shaped corner is formed with a chamfer, and the radius of the chamfer is 0.5-10mm, preferably 3.5mm.
[0034] In the embodiment, based on the design, the light rays of the transmitted excitation light can form at least 8 reflections in the light extinction channel formed between the side baffle 30 and the L-shaped corner without entering the main light channel. The reflectivity of the surface of the structure 10 after the matt oxidation treatment is generally between 10%-20%. After 8 reflections, the maximum light energy is only 0.28=2.56*10 -6 The reflectivity of the dichroic mirror in the fluorescence microscope is generally greater than 90%. The maximum transmittance is 10%, that is, the stray light energy after the light extinction treatment is 2.56*10 -7 After most of the small-angle stray light is filtered out by the emission sheet 14, the energy is almost gone, so the stray light cannot interfere with the emission fluorescence signal.
[0035] Please refer to Figure 3 The utility model discloses a second embodiment further provides a kind of fluorescence detection system, it includes objective lens 200, tube lens 300, receiving surface 400 and as above-mentioned can eliminate excitation fluorescence background stray light optical structure 100.
[0036] Wherein, incident excitation light transmits light laser sheet 111 and reaches the dichroic mirror 20, and the dichroic mirror 20 simultaneously reflects and transmits the excitation light, and the reflected excitation light enters the objective lens 200 through the third side wall 14, and then reaches the fluorescence sample 300 through the objective lens 200, and then carries the fluorescence sample information after being reflected by the fluorescence sample, and then sequentially reaches the receiving surface 500 through the objective lens 200, the structure 10 and the tube lens 400.
[0037] The utility model discloses a through hole is arranged on the side wall of the structure piece loaded with dichroic mirror, and the side baffle with inclination angle is matched, so that the excitation light can be reflected multiple times in the light extinction channel formed by the corner and the side baffle, to avoid the light pollution caused by the reflection of excitation light rays in the whole equipment. The scheme has the advantages of low cost, easy operation, remarkable effect and the like.
[0038] The above merely describes a preferred embodiment of the present application, and the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.
Claims
1. An optical structure capable of eliminating excitation fluorescence background stray light, characterized in that, The application relates to an optical structure capable of eliminating excitation fluorescence background stray light, which comprises the following parts: a structural member having a first side wall as an incident surface and a second side wall opposite to the first side wall, and a corner being formed outside the second side wall; the second side wall is provided with a through hole for light emission; a dichroic mirror is accommodated in the structural member, which is configured to receive excitation light incident from the first side wall and output the transmitted excitation light from the through hole of the second side wall; a side baffle is obliquely arranged at the corner, which is configured to reflect the excitation light output from the through hole for multiple times in the corner and the light extinction channel of the side baffle.
2. The optical structure capable of eliminating the excitation fluorescence background stray light according to claim 1, characterized in that, The inner wall of the through hole is provided with light extinction threads.
3. The optical structure capable of eliminating the excitation fluorescence background stray light according to claim 1, wherein, The corner is an L-shaped corner, and two ends of the side baffle are arranged on two sides of the L-shaped corner.
4. The optical structure capable of eliminating the excitation fluorescence background stray light according to claim 3, characterized in that, The included angle between the side baffle and the outer side of the second side wall is 25-75 degrees.
5. The optical structure capable of eliminating the excitation fluorescence background stray light according to claim 3, wherein, The L-shaped corner is formed with a chamfer, and the surface is subjected to dull oxidation treatment.
6. The optical structure capable of eliminating the excitation fluorescence background stray light according to claim 5, wherein, The radius of the chamfer is 0.5-10 mm.
7. The optical structure capable of eliminating the excitation fluorescence background stray light according to claim 1, wherein, The incident surface is provided with a laser sheet.
8. The optical structure capable of eliminating the excitation fluorescence background stray light according to claim 1, wherein, The reflection times are at least 8 times.
9. The optical structure capable of eliminating the excitation fluorescence background stray light according to claim 1, wherein, The side surface of the structural member close to the receiving surface is further provided with an emission sheet.
10. A fluorescence detection system characterized by, The application further relates to an optical structure capable of eliminating excitation fluorescence background stray light, which comprises an objective lens, a tube lens, a receiving surface and the optical structure capable of eliminating excitation fluorescence background stray light as claimed in any one of claims 1 to 9.