Polarization regulation device and method and laser interference type structured light illumination microscope system

Abstract

The invention discloses a polarization regulation device and method and a laser interference type structured light illumination microscope system. The disclosed polarization regulation device comprises two Pockels cells or two liquid crystal phase delayers, incident light passes the first and second Pockels cells or the first and second liquid crystal phase delayers in order, and the two Pockels cells or two liquid crystal phase delayers are used to regulate the polarization state of the incident light. In the laser interference type structured light illumination microscope system, output light, of incident light polarized light (including diffracted light in 0 level and +/-1 level) in different direction angles, after passing the polarization regulation device if of linear polarization inparallel with the polarization direction, it can be ensured that two or three interference light beams in a focal plane after input to an object lens of a large aperture are of s polarization, and anoptimal structured light modulation degree is obtained.

Description

[0001] The invention belongs to the field of microscopic imaging, and in particular relates to a polarization control device and method and a laser interference structured light illumination microscope system, in particular to a polarization control method suitable for the laser interference structured light illumination microscope system. Background technique [0002] SIM technology is the fastest imaging speed among all current super-resolution fluorescence microscopy techniques, and is the most suitable method for real-time imaging of live cells. For the laser interferometric SIM system, the polarization state of the interfering light and the numerical aperture of the objective lens are the main factors affecting the contrast of the interference fringes. In particular, almost all current SIM systems use large numerical aperture objectives for imaging. In order to ensure that the excitation light produces high-contrast structured light fringes on the focal plane of the object...

AI Technical Summary

Problems solved by technology

The incident linearly polarized light is modulated into circularly polarized light after passing through a quarter-wave plate, and the outgoing light is linearly polarized after passing through a pizza polarizer, but the energy loss is more than 50%, and the processing technology of the pizza polarizer is complicated and expensive;

[0005] (3) The third method: using a control scheme of a zero-order vortex half-wave plate, using the characteristics of programmable control of the fast axis distribution of the zero-order vortex half-wave plate, the incident linearly polarized light is modulated by the wave plate and then the outgoing light The polarization direction is in the same direction at the spatially symmetrical position, which can ensure that the polarization direction of the ±1st-order interference light of the illumination is parallel to obtain the best fringe contrast; however, most zero-order vortex half-wave plates can only perform polarization accuracy for a single central wavelength. Modulation, which cannot meet the requirements of multi-channel SIM imaging;

[0007] However, since the achromatic quarter-wave plate is not absolutely achromatic in the visible light band (400-700nm), the measured phase retardation after incident light of different wavelengths passes through the achromatic quarter-wave plate is no longer exactly equal to λ / 4, but fluctuates up and down relative to λ / 4, and eventually the outgoing light after the polarized light passes through the LCVR and the achromatic quarter-wave plate is not linearly polarized but elliptically polarized, and the ellipse varies with the excitation wavelength different rates

The contrast of the interference fringes produced by the above-mentioned elliptically polarized light interference on the focal plane of the objective lens is usually worse than that of two linearly polarized light beams with the same s polarization; the SIM image reconstruction algorithm is used to process such low-modulation images, and it is easy to reconstruct the image. Artifact interference

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