Differential dark-field confocal microscopic measurement apparatus and method based on polarized vector light beam

A differential dark-field confocal microscopic measurement apparatus based on a polarized vector light beam, comprising a vector polarized illumination light generation module, a light beam scanning illumination module and a differential dark-field confocal imaging module;

• the vector polarized illumination light generation module comprises the following components in sequence according to a direction of light propagation:
• a laser and a first non-polarizing beam splitter, wherein the first non-polarizing beam splitter divides a laser propagation path into a first path and a second path, the first path involves the following components in sequence according to a direction of light propagation:
• a first acousto-optic modulator, a first reflecting mirror, a first half-wave plate, a first vortex wave plate and a second reflecting mirror and a second non-polarizing beam splitter;
• the second path involves the following components in sequence according to a direction of light propagation:
• a second acousto-optic modulator, a second half-wave plate, a second vortex wave plate and a second non-polarizing beam splitter;
• and the second non-polarizing beam splitter combines the first and second laser beams, and propagates them to the light beam scanning illumination module;
• the light beam scanning illumination module comprises the following components in sequence according to a direction of light propagation:
• a beam expander, an aperture diaphragm, a third non-polarizing beam splitter, an objective lens and a sample to be detected, wherein the third non-polarizing beam splitter divides the laser light into two paths, one path thereof is propagated to the sample to be detected through the objective lens, and the other path thereof is propagated to the differential dark-field confocal imaging module;
• and the differential dark-field confocal imaging module comprises the following components in sequence according to a direction of light propagation:
• a third vortex wave plate, a polarizing plate, a focusing lens, a single-mode optical fiber, and a PMT detector.