Asymmetric-incidence-based sample axial position tracking and correcting method and device

Abstract

The invention discloses an asymmetric-incidence-based sample axial position tracking and correcting method and device. The device comprises a laser, a single-mode optical fiber, a collimating lens, a polarizer, a polarization converter, a 0 / Phi phase plate, a space filtering assembly, a 3 / 4 baffle plate, a beam splitter prism, a microscope objective lens, a monitoring light beam focusing lens, a photoelectric induction device, a computer and a three-dimensional nano scanning platform. The method comprises the following steps of: converting a collimating light beam into a second tangential polarized light, wherein polarization directions of each point on the cross section of the second tangential polarized light are symmetric in respect to two symmetric axes which are mutually vertical at the same time, forming asymmetric incident light beams, focusing the asymmetric incident light beams, and projecting the asymmetric incident light beams onto a sample; meanwhile, collecting light beams reflected by the sample as a monitoring light beam, and monitoring axial position shift of the sample and tracking and correcting the axial position of the sample according to center-of-gravity shift of a focusing spot of the monitoring light beam. The asymmetric-incidence-based sample axial position tracking and correcting method and device disclosed by the invention can be applied to sample axial position real-time monitoring and correcting in a high-accuracy super-resolution microscope system.

Description

technical field [0001] The invention belongs to the field of high-precision and super-resolution microscopy, in particular to a method and device for tracking and correcting the axial position of a sample based on asymmetric incidence. Background technique [0002] In a super-resolution microscope system, the sample to be tested needs to be placed at the focal plane of the microscope objective. However, during the scanning process, due to factors such as thermal drift and stress drift, the sample to be tested will inevitably drift axially over time and deviate from the focal plane, which will seriously affect the imaging accuracy of the microscope system. Especially for microscopic methods that require multiple repeated scans of the same pixel, the impact of this axial drift will be more obvious, because the axial drift may cause multiple repeated scans that are not for the same pixel. Therefore, in order to improve the measurement accuracy of the microscopic system, the a...

AI Technical Summary

Problems solved by technology

In 2004, the Chinese invention patent with the patent number ZL200410006359.6 proposed a differential confocal scanning detection method with high spatial resolution. Although this method partially solves the problem of tracking the axial position of microscopic samples, it can better Improve the measurement accuracy of the microscopic system, and effectively avoid the influence of the energy drift of the laser used in the system on the tracking effect, but the measurement range of this method is small, so that it still has great limitations in use

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