Device for realizing femtosecond time resolution imaging of weak phase object based on vortex filtering

Abstract

The invention relates to a device for realizing femtosecond time resolution imaging of a weak phase object based on vortex filtering. The device comprises a detection unit and a pumping unit. After light emitted by the femtosecond laser light source passes through a beam splitter, transmitted light enters the detection unit as detection light, and reflected light enters the pumping unit as pumping light; a vortex filter is added into the detection unit to introduce a geometric phase, and a weak phase object is introduced into a detection light incident plane to realize high-contrast imaging of the weak phase object in a dark background; an ultrafast time resolution optical delay device is introduced into the pumping unit, the optical path between a pumping light path and a detection light path is controlled and adjusted, time resolution of a weak phase object is achieved, and imaging detection of the ultrafast dynamic process of the weak phase object is achieved. The device is applied to detection of weak phase objects in the biological field, such as biological cells and transparent organisms; and high-contrast imaging of a weak phase object in a dark background and imaging detection of an ultrafast dynamic process are realized.

Description

technical field [0001] The invention relates to an imaging technology, in particular to a femtosecond-level time-resolved imaging device for weak-phase objects based on vortex filtering. Background technique [0002] Vortex light is a special beam in which the equiphase surface presents a helical shape during transmission, and has a helical phase factor e imθ , where θ is the azimuth angle; m is the topological charge, also known as the quantum number of orbital angular momentum; i is the imaginary unit. Due to the presence of a phase singularity in the center, the vortex light presents a dark hollow ring distribution, that is, the central field amplitude is zero, and a dark region with zero brightness appears on the beam section, which is called an optical vortex. Compared with ordinary Gaussian beams, vortex light has the advantages of good confidentiality, large transmission capacity, high efficiency, and easy encoding and decoding. It has broad application prospects in ...

AI Technical Summary

Problems solved by technology

[0004] Although image edge enhancement through radial Hilbert transform can play a certain role in the imaging field, its low contrast obviously limits its application in weak phase or weak signal imaging.

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