Wavefront Deformation Measurement Using Centro-Symmetric Defocus
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Solution Overview
Problem
Current wavefront analysis techniques, such as phase diversity, require multiple images or additional optical components, which can be cumbersome and limited by temporal evolution of phenomena, especially in applications requiring real-time corrections.
Innovation Solution
A method and device that measure wave surface deformations using a single image by generating a computer model of the image pattern based on optical system characteristics and introducing a centro-symmetric additional deformation, such as defocusing, to eliminate sign ambiguity and simplify the measurement process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If phase diversity technique is used to eliminate sign ambiguity, then measurement precision is improved, but device complexity increases due to requiring additional optical components or multiple images
Solution Approach 1:
The invention changes the parameter of the imaging system by introducing a known defocus amount to alter the point spread function. This parameter change enables the system to resolve the sign ambiguity of wavefront deformations without requiring additional optical components, thereby improving measurement precision while avoiding increased device complexity
Solution Approach 2:
The invention performs a preliminary action by pre-introducing a known defocus amount before the actual wavefront measurement. This preliminary modification of the optical path allows the subsequent single image to contain sufficient information for unambiguous deformation measurement, eliminating the need for multiple images or additional sensors
2Measurement precision
If multiple images are acquired to resolve phase ambiguity, then measurement precision is improved, but loss of time increases due to sequential measurement requirements
Solution Approach 1:
The invention introduces a known defocus amount as a preliminary action before capturing the single image. This pre-modification ensures that the captured image contains encoded information about the wavefront deformations without requiring subsequent images, thereby achieving precise measurement while minimizing measurement time
Solution Approach 2:
The invention creates a modified copy of the optical path by introducing defocus, which encodes the wavefront information in a way that can be uniquely decoded from a single image. This copying approach with known modification allows time-efficient measurement while maintaining precision
3Measurement precision
If auxiliary optical components are added to implement phase diversity, then measurement precision is improved, but ease of operation deteriorates due to complicated setup
Solution Approach 1:
The invention achieves improved measurement precision by changing the focus parameter of the existing imaging system rather than adding auxiliary optical components. This approach maintains the simplicity of the original setup while enabling accurate wavefront deformation measurement through computational methods
Data Source
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AI summary
The method involves generating a predetermined additional incident deformation (45) e.g. spherical aberration, nearer to a focal plane (30) of an optical system (1) e.g. telescope. The generated deformation is added to wave surfaces (19) that are associated to source points from the plane. An image of the source points that are associated to the surfaces, is acquired. The acquired image is processed for measuring searched incident deformations (18) from the acquired image and from the generated additional deformation. An independent claim is also included for wave surface deformation measuring device comprising a generating unit.