Structured Illumination Phase Control via Pupil Plane Diffraction
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Solution Overview
Problem
Existing microscopy techniques using structured illumination for depth discrimination and resolution enhancement face challenges in accurately controlling phase angles and orientations of periodic structures, leading to artifacts and requiring frequent recalibration, especially in high-resolution applications.
Innovation Solution
A configuration that simplifies the control of phase shifts and orientations of periodic structures by manipulating diffraction orders in the pupil plane of the objective lens, allowing for precise setting of phase angles and orientations using a single mechanical actuator, independent of wavelength, and eliminating the need for precise control elements, thus reducing artifacts and recalibration requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If precise control elements (piezo actuators, galvanometer scanners) are used to control phase angles and orientations, then measurement precision and manufacturing precision improve, but device complexity increases and recalibration is frequently required
Solution Approach 1:
The patent extracts the periodic structure from the specimen plane and relocates it to the back focal plane of the objective lens. This separation eliminates the need for complex control elements to manipulate the structure in the specimen plane, as the diffraction orders in the back focal plane can be manipulated more simply with a single mechanical actuator.
Solution Approach 2:
The back focal plane of the objective lens serves as an intermediary space where the periodic structure is projected. This intermediate plane allows for simplified manipulation of diffraction orders using a single mechanical actuator, avoiding the complexity of directly controlling multiple phase angles and orientations in the specimen plane.
2Measurement precision
If multiple control elements are used to adjust phase angles and orientations, then control accuracy improves, but the speed of changing settings decreases
Solution Approach 1:
The patent combines multiple control functions (phase angle adjustment and orientation control) into a single mechanical actuator that manipulates the periodic structure in the back focal plane. This merging of functions maintains control accuracy while significantly increasing the speed of changing settings, enabling high-speed scanning.
3Ease of operation
If the periodic structure is manipulated directly in the specimen plane, then ease of operation improves, but manufacturing precision deteriorates due to artifacts like striations
Solution Approach 1:
The patent replaces direct mechanical manipulation of the periodic structure in the specimen plane with optical manipulation of diffraction orders in the back focal plane. This substitution eliminates mechanical errors and artifacts like striations while maintaining ease of operation through simple actuator movement in the back focal plane.
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
This configuration enables high-speed scanning with improved precision and reproducibility, reducing artifacts and allowing operation across a wide range of wavelengths, while maintaining high resolution and contrast, without the need for complex control systems like piezo actuators or galvanometer scanners.
Implementation Method 1
a periodic structure (for example, a grating) which is located in a plane conjugate to the specimen and which generates structured illumination in the specimen generates a diffraction distribution in the pupil of the objective lens
Data Source
AI summary
A method for the optical detection of an illuminated specimen, wherein the illuminating light impinges in a spatially structured manner in at least one plane on the specimen and several images of the specimen are acquired by a detector in different positions of the structure on the specimen. An optical sectional image and/or an image with enhanced resolution is then calculated. The method includes generating a diffraction pattern in the direction of the specimen in or near the pupil of the objective lens or in a plane conjugate to the pupil. A phase plate with regions of varying phase delays is dedicated to the diffraction pattern in or near the pupil of the objective lens or in a plane conjugate to said pupil, and different phase angles of the illuminating light are set.