Conjugated bi-pass lighting confocal microscopic device of fluorescent reflecting mirror

Abstract

A conjugated bi-pass lighting confocal microscopic device of a fluorescent reflecting mirror belongs to an optical micro measurement technology. A collimation beam expander and a beam splitter are sequentially arranged on a direct light path of a laser, a focusing object lens and a three-dimensional micromovement object stage are arranged on the reflected light path of the light splitter, a narrow-band filter and a converging object lens are arranged on the transmission light path of the beam splitter, transmission optical fibers transmit the converging light of the converging object lens to a photodetector, an ellipsoidal reflector is also arranged on the reflected light path of the beam splitter, the perifocus of the ellipsoidal reflector is positioned a sample surface which is put on the three-dimensional micromovement object stage, and the fluorescent reflecting mirror is arranged at the apofocus of the ellipsoidal reflector. The microscopic device prevents the interference which is generated by the mixed light-wave superposing which is caused by primary lighting and secondary lighting of bi-pass lighting, and has high signal-to-noise ratio and axial resolution.

Description

technical field [0001] The invention belongs to optical microscopic measurement technology, and mainly relates to an ultra-precise measuring instrument for three-dimensional microstructure, microstep, microgroove line width, depth and surface shape measurement in microstructured optical elements, microstructured mechanical elements, and integrated circuit elements. Non-contact measuring device. Background technique [0002] Confocal scanning measurement is one of the important technical means to measure three-dimensional microstructure, micro-step, micro-groove line width, depth and surface shape in the fields of micro-optics, micro-mechanics and micro-electronics. The basic idea is to introduce a pinhole detector Stray light is suppressed and axial tomography capability is produced, but traditional confocal technology has always been limited by the principle that the numerical aperture of traditional lens imaging is less than 1. [0003] Double-pass illumination confocal m...

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Problems solved by technology

[0004] The main disadvantage of the traditional double-pass illumination confocal measurement method is the interference disturbance of the primary illumination light and the secondary illumination light, which reduces the signal-to-noise ratio and is not conducive to the improvement of the axial resolution.

However, the commonality between the traditional two-pass illumination confocal measurement method and the confocal measurement method proposed by Minsky is that the system resolution is closely related to the numerical aperture of the collecting objective lens. The larger the numerical aperture, the higher the axial resolution. The principle limitation of the traditional lens imaging numerical aperture is less than 1, both of which are difficult to further improve the axial resolution by increasing the numerical aperture

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