CN106547099A - A kind of flow cytometer beam shaping system based on polarized light - Google Patents

Abstract

The invention discloses a flow cytometer beam shaping system based on polarized light. The shaping system includes a laser, a polarization generator and a shaping lens, and also includes a 1/4 wave plate and components for canceling polarization. A polarization generator is used to change the polarization state of the laser beam, and a shaping lens is used to shape it to form a single-cell illumination spot. The present invention proposes to change the polarization state of the laser beam of the flow cytometer to form a polarized spot for single-cell illumination, and introduce the polarized spot into the cell illumination and fluorescence excitation, which has a significant effect on the subsequent scattered light and fluorescence detection spectroscopic structure and detection light spectrum separation. Positive impact, effectively reducing the impact of stray light on both.

Description

A Beam Shaping System for Flow Cytometry Based on Polarized Light

technical field

The invention relates to the field of instruments based on flow cytometry, in particular to a flow cytometer beam shaping system based on polarized light.

Background technique

The quality of the laser beam not only affects the overall performance of the laser, but also greatly affects the application level of laser technology. Usually the spatial intensity distribution of the laser beam emitted by the laser is a Gaussian distribution, that is, a Gaussian laser beam. In many applications, a uniform distribution of the laser beam is desired. Therefore, shaping the laser beam has become particularly important, resulting in a variety of laser beam shaping technologies, such as liquid crystal spatial light modulator, double-lens refraction combination type, cylindrical mirror shaping and so on.

Flow cytometers have certain requirements for the diameter and light intensity distribution of the fluorescence excitation beam. Existing commercially available lasers cannot meet this special requirement. The size of the flow system and the successful excitation of the labeled test cells in the cell suspension. A laser beam illuminates the cells under test in the cytosol flow and excites fluorescence. The light intensity distribution determines the degree of excitation of the measured cells, and the beam size determines the number of cells excited at the same time, both of which will have a direct impact on subsequent measurements. The light intensity distribution of the illumination beam conforms to Gaussian, and the edge intensity is about the center 13.5% of the intensity, the light intensity increase is 78% at a radius of 1/3, and the light intensity increase at 1/10 of the radius is 98%. At present, most of the illumination spots of flow cytometers are compromised elliptical beams with a size of 20 μm×60 μm, and the short axis direction is parallel to the exit direction of liquid flow. This light beam can provide time resolution in the direction of the short axis, that is, only one cell is allowed to pass through at a time. The shorter the short axis, the faster the cell can pass through, but the higher the performance requirements for the subsequent optical path detection system, in the long-term The axial direction can provide relatively uniform illumination for the measured cells that deviate from the center of the liquid flow.

At present, the illumination spot of the flow cytometer is mostly realized by two orthogonally placed cylindrical lens groups. The cylindrical lens is a special aspheric optical device with different radii on the x-axis and y-axis, so the shape of the lens It is cylindrical or semi-cylindrical, and only a single optical axis has image magnification, and its function is equivalent to flat glass in the other direction. Using the single optical axis image magnification function of the cylindrical mirror can carry out individual and specific size integering on a certain axis of the circular light spot.

Contents of the invention

The polarized light-based flow cytometer beam shaping system of the present invention adopts a polarization optical system, and utilizes the polarization analysis of a polarization state generator to realize the shaping of the flow cytometer illumination spot.

The technical solution of the present invention is: a flow cytometer beam shaping system based on polarized light, the laser shaping system includes a laser, a polarization generator and a shaping lens arranged in sequence along the direction of the laser light path.

Preferably, the positional relationship between the polarization generator and the shaping lens is that the polarization generator is placed in front of the shaping lens or the polarization generator is placed behind the shaping lens.

Preferably, the light beam emitted by the polarization state generator is fully polarized light or partially polarized light.

Preferably, the shaping lens is generally non-polarized or polarized.

Preferably, there is a 1/4 wave plate in front of the polarization generator.

Preferably, the shaping lens is composed of two aspheric lenses, and the two aspheric lenses are matched with each other, one of which is an aspheric concave mirror and the other is an aspheric convex mirror or both are aspheric convex mirrors.

Preferably, the laser shaping system further includes an optical device for canceling the polarization state.

Preferably, the beam shaping system further includes an auxiliary device, the auxiliary device includes a housing, a base plate, a laser device, a polarization generator, and a shaping lens device; the base plate is fixed on the bottom of the housing, and the laser device, The installation of the polarization generator and the installation of the shaping lens device are respectively movably connected with the base plate through fasteners; the installation of the laser device, the installation of the polarization generator and the installation of the shaping lens device are respectively provided with through holes, and the geometric centers of the through holes are on the same line. in a straight line.

The beneficial effect of the present invention is that: a polarized light-based flow cytometer beam shaping system of the present invention adopts a polarization optical system to realize the polarization of the flow cytometer illumination spot. The present invention proposes to change the polarization state of the laser beam of the flow cytometer to form a polarized spot for single-cell illumination, and introduce the polarized spot into the cell illumination and fluorescence excitation, which has a significant effect on the subsequent scattered light and fluorescence detection spectroscopic structure and detection light spectrum separation. Positive impact, can effectively reduce the impact of stray light on both.

Description of drawings

With reference to the accompanying drawings, more objects, functions and advantages of the present invention will be clarified through the following description of the embodiments of the present invention, wherein:

Fig. 1 shows an effect diagram of an auxiliary device of a flow cytometer beam shaping system based on polarized light in the present invention;

Fig. 2 shows CCD gray scale distribution discretization Gaussian fitting figure of the present invention;

Fig. 3 schematically shows a schematic structural view of a flow cytometer beam shaping system based on polarized light in the present invention;

Fig. 4 schematically shows a schematic structural diagram of Embodiment 2 of a flow cytometer beam shaping system based on polarized light in the present invention;

Fig. 5 schematically shows a schematic diagram of Embodiment 3 of a flow cytometer beam shaping system based on polarized light according to the present invention.

detailed description

The objects and functions of the present invention and methods for achieving the objects and functions will be clarified by referring to the exemplary embodiments. However, the present invention is not limited to the exemplary embodiments disclosed below; it can be implemented in various forms. The essence of the description is only to help those skilled in the relevant art comprehensively understand the specific details of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the drawings, the same reference numerals represent the same or similar components, or the same or similar steps.

Fig. 1 is an effect diagram of an auxiliary device of a flow cytometer beam shaping system based on polarized light according to the present invention. As shown in Figure 1, the light beam is emitted by the laser and enters the shaping system. The shaping system realizes two processes of shaping and polarization; the light beam enters the system to undergo the shaping process first and then the polarization process, or the polarization process can be performed first and then the shaping process.

As shown in FIG. 1 , the auxiliary device includes a bottom plate 101 , a housing 102 , a laser device 103 , a polarization generator device 104 and a shaping lens device 105 . The laser device 103, the polarization generator device 104 and the shaping lens device 105 are respectively fixed on the bottom plate 101 by detachable fasteners.

The bottom plate 101 and the shell 102 are made of lightweight metal materials, and the bottom plate 101 and the shell 102 are rectangular. The bottom plate is placed inside the shell 102 and fixed to the bottom of the shell 102 by nuts.

The installation laser device 103 is provided with a circular through hole, which matches the outer diameter of the laser; the installation polarization state generator device 104 is a U-shaped frame structure, and the U-shaped frame is provided with a rectangular through hole, and the size of the through hole is related to the polarization state generation The shape and size of the lens are matched to facilitate the transmission of light beams; the installation shaping lens device 105 is a U-shaped frame structure, and the U-shaped frame is provided with a rectangular through hole to facilitate transmission of light beams. The geometric centers of the circular through hole and the two rectangular through holes are on the same straight line.

Fig. 2 is a Gaussian fitting diagram of the discretization of the gray distribution of the CCD of the present invention.

A CCD camera is used to obtain the cross-sectional spot of the beam, and Matlab software is used to further process the collected image to analyze its size and intensity distribution.

The specific processing process is to read and draw the gray value of each pixel collected by the CCD, discretize the gray value curve, and then perform Gaussian fitting to obtain the discrete Gaussian fitting graph of the CCD gray distribution shown in Figure 2. The fitted curve shown in Figure 2 conforms to the normal distribution function. The fitting curve is very close to the original data, and it is not affected by the saturation of light intensity, and the actual light intensity in the saturation area can be estimated (not exceeding the saturation value of 255). Spot analysis is performed according to Gaussian parameters, and the spot diameter is calculated according to a certain light intensity.

Example 1

In this embodiment, the laser 301 is a Nd:YAG fixed laser, and the shaping lens is a shaping lens formed by combining two aspherical convex mirrors.

Fig. 3 is a structural schematic diagram of a flow cytometer beam shaping system based on polarized light according to the present invention. As shown in FIG. 3 , a flow cytometry beam shaping system based on polarized light includes a laser 301 , a polarization generator 302 and a shaping lens 303 .

The laser 301 emits a laser beam in the shape of a circular spot. The polarization state of the laser beam is changed by the polarization generator 302. The outgoing beam is an elliptical spot, which is shaped by the shaping lens 303 to form a single-cell illumination spot.

Example 2

Fig. 4 is a structural schematic diagram of a flow cytometer beam shaping system based on polarized light according to the present invention. As shown in FIG. 3 , a flow cytometry beam shaping system based on polarized light includes a laser 301 , a polarization state generator 302 , a shaping lens 303 and an optical device 304 for canceling the polarization state. The difference between this embodiment and Embodiment 1 is that an optical device 304 for canceling the polarization state is installed behind the shaping lens 303. The optical device 304 for canceling the polarization state is, for example, a polarization scrambler, and the polarization-related damage is eliminated by using the polarization scrambler.

Example 3

In this embodiment, the laser 501 is a Nd:YAG fixed laser, and the shaping lens 504 is a shaping lens formed by combining an aspheric concave mirror and an aspheric convex mirror.

Fig. 5 is a structural schematic diagram of a flow cytometer beam shaping system based on polarized light according to the present invention. As shown in FIG. 5 , a flow cytometry beam shaping system based on polarized light includes a laser 501 , a 1/4 wave plate 502 , a polarization generator 503 and a shaping lens 504 . The difference between this embodiment and Embodiment 1 is that a 1/4 wave plate 502 is arranged directly in front of the polarization generator 503, and the polarization direction of the incident light beam is adjusted by using the 1/4 wave plate 502 to rotate the polarization direction of the light beam by θ /4, change the shape and size of the spot.

Other embodiments of the invention will be apparent to and understood by those skilled in the art from consideration of the specification and practice of the invention disclosed herein. The description and examples are considered exemplary only, with the true scope and spirit of the invention defined by the claims.

Claims (8)

1. A flow cytometer beam shaping system based on polarized light, the beam shaping system includes a laser, a polarization generator and a shaping lens arranged in sequence along the laser light path direction. 2 . The polarized light-based flow cytometer beam shaping system according to claim 1 , wherein the polarization generator is placed in front of the shaping lens or the polarization generator is placed behind the shaping lens. 3 . 3 . The polarized light-based flow cytometer beam shaping system according to claim 1 , wherein the beam emitted by the polarization state generator is fully polarized or partially polarized. 4 . 4 . The polarized light-based flow cytometer beam shaping system according to claim 1 , characterized in that: the shaping lens is generally non-polarized or polarized. 5. A polarized light-based flow cytometry beam shaping system according to claim 1, characterized in that: there is a 1/4 wave plate in front of the polarization generator. 6. A kind of flow cytometer beam shaping system based on polarized light according to claim 1, characterized in that: said shaping lens is matched with two aspheric lenses, one of which is an aspheric concave mirror and the other is an aspheric convex mirror or both are aspheric convex mirrors. 7. A polarized light-based flow cytometer beam shaping system according to claim 1, characterized in that: said laser shaping system further comprises an optical device for canceling polarization state. 8. A kind of flow cytometer beam shaping system based on polarized light according to claim 1, characterized in that, said beam shaping system also includes auxiliary devices, said auxiliary devices include a housing, a base plate, a laser device 1. Install the polarization generator and the shaping lens device; the bottom plate is fixed on the bottom of the housing, and the laser device, the polarization generator and the shaping lens device are respectively connected to the bottom plate through fasteners; the laser device, the polarization The state generator and the device for installing the shaping lens are respectively provided with through holes, and the geometric centers of the through holes are on the same straight line.