STED (stimulated emission depletion)-based device and method for measuring smooth free-form surface sample

Abstract

The invention relates to an STED (stimulated emission depletion)-based device and method for measuring a smooth free-form surface sample, belonging to the field of the optical microscopic measurement. The device comprises a first picosecond pulse laser, a first conduction optical fiber, a first collimator objective, a first plane reflecting mirror, a second picosecond pulse laser, a second conduction optical fiber, a second collimator objective, a second plane reflecting mirror, a vortex-shaped phase modulation plate, a half-wave plate, a first dichroscope, a second dichroscope, a quarter-wave plate, a focusing object lens, a coating sample, a three-dimensional micro-displacement carrier table, an optical filter, a collection object lens, a pin hole and a photoelectric detector. The surface of the sample is coated with a fluorescent membrane, so that an industrial sample can be measured by utilizing the STED microscopy; meanwhile, the fluorescent membrane radiates fluorescence in different directions under the illumination of the laser, so that the problem that the signal light is difficult to collect caused by the mirror reflection of the light beam on a smooth free-form surface can be avoided. By adopting the device and method, the surface appearance of the smooth sample with a large angle between a normal and the optical axis direction can be high precisely measured.

Description

technical field [0001] The device and method for measuring smooth free-form surface samples based on STED belong to the field of optical microscopic measurement. Background technique [0002] For a sample with a smooth free-form surface, in the area where the angle between the normal line and the optical axis direction is large, the light illuminating the sample surface cannot be completely collected or almost cannot be collected due to specular reflection, so the surface morphology cannot be determined. High-precision measurement, even impossible to measure. Therefore, how to measure a sample with a smooth free-form surface with a large slope with high precision has become a difficult problem in the field of optical measurement. [0003] In the field of sample surface topography measurement, laser scanning confocal microscopy (LSCM) is a commonly used method. This method adopts precise pinhole filtering technology, so that only the information on the focal plane can be de...

AI Technical Summary

Problems solved by technology

Since the measurement objects in the field of industrial measurement cannot emit fluorescence, STED microscopy devices are mainly used in the field of biological microscopic imaging, and there is no precedent for application in the shape measurement of industrial samples.

Even if STED microscopy is simply transplanted to the field of industrial sample shape measurement, it cannot overcome the problem that the light intensity of the collected signal is extremely weak due to the specular reflection of the beam on the sample surface with a smooth free-form surface

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