Vortex Dichroism Microscopy for Chirality and Defect Detection
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Solution Overview
Problem
Existing dark-field confocal microscopic measurement technologies are unable to detect chirality in micro-nano structures and defects in optical elements, limiting their ability to characterize and classify defects comprehensively.
Innovation Solution
A dark-field confocal microscopic measurement apparatus and method based on vortex dichroism, which utilizes vortex scattering dichroism spectrum analysis to obtain chirality information of micro-nano structures, and employs multi-order vortex light illumination to detect structural and defect information in micro-structure samples.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If ordinary dark-field confocal microscopic measurement technology is used, then geometrical defects can be detected, but chirality information and physical properties of defects cannot be acquired
Solution Approach 1:
The detection process is segmented into multiple imaging modes: dark-field confocal imaging for geometrical defects and vortex dichroism imaging for chirality information. Each mode targets specific defect characteristics, allowing comprehensive acquisition of both geometrical and physical properties without information loss
Solution Approach 2:
The measurement apparatus is designed with multi-functionality to perform both ordinary dark-field confocal imaging and vortex dichroism imaging. By integrating multiple detection capabilities into a single system, it can acquire diverse defect characteristics including geometrical features, chirality information, and physical properties, thereby enhancing overall adaptability
2Measurement precision
If single-mode imaging is used, then device complexity is low, but detection precision for chirality is insufficient
Solution Approach 1:
The system dynamically switches between different imaging modes based on detection requirements. The apparatus can transition from ordinary dark-field confocal mode to vortex dichroism mode by adjusting optical parameters, enabling high-precision chirality detection only when needed, thus balancing measurement precision with operational simplicity
Solution Approach 2:
Vortex light serves as an intermediary tool to enable chirality detection. By introducing vortex light with specific topological charges as illumination, the system can extract chirality information from samples without requiring fundamentally different detection equipment, thereby achieving high measurement precision while controlling device complexity
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The apparatus and method enable the detection of chirality information and physical properties of micro-nano structures, improving the sensitivity and accuracy of defect detection in optical elements, and providing a new approach for micro-nano structure analysis.
Implementation Method 1
an array vortex wave plate, to generate vortex illumination light beams
Implementation Method 2
The array vortex wave plate includes a vortex phase array, each vortex phase distribution exp (imφ) corresponds to an order m
Implementation Method 3
the objective lens focuses array vortex beam on the sample to be detected placed on the three-dimensional moving stage
Implementation Method 4
the scattered light is collected to obtain vortex dichroic scattering signals
Implementation Method 5
the aperture diaphragm array, a focusing lens, a single-mode optical fiber and a PMT detector, and the scattered light is collected
Implementation Method 6
a PMT detector, and the scattered light is collected to obtain vortex dichroic scattering signals
Implementation Method 7
Vortex light illumination is generated through an array vortex wave plate, scattering signals are then extracted, and at the same time, intensity differences between the scattering signals under the illumination of ±m-order vortex light are identified to observe vortex dichroism
Data Source
AI summary
Disclosed are a dark-field confocal microscopic measurement apparatus and method based on vortex dichroism. The apparatus includes an array vortex light generation module, an array vortex light illumination module and an array dark-field confocal detection module; an array vortex wave plate of the array vortex light generation module generates vortex light to illuminate a sample of the array vortex light illumination module; and the array dark-field confocal detection module extracts scattering signals, and identifies differences between scattering signals collected under the illumination of opposite-order vortex light. Three-dimensional distribution information of defects, such as subsurface scratches, abrasion, subsurface cracks, and bubbles, can be extracted by directly analyzing the scattering signals under the 1-order vortex illumination; and chirality information of the micro-nano material can be obtained by analyzing difference values of the scattering signals under the illumination of the opposite-order vortex light.