Pinhole Stitching Measurement for Complex Surface Shapes
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Solution Overview
Problem
The existing point diffraction interferometers face limitations in achieving high lateral resolution for complex surface shapes and large-diameter apertures, particularly in optical systems, due to the resolution being compromised as the detection aperture increases.
Innovation Solution
The integration of three optical adjustable shelves that can be rotated and translated allows for annular aperture stitching and sub-aperture stitching measurements, enhancing the lateral resolution of a conventional point diffraction interferometer to detect surface shapes with larger apertures and complex lens shapes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the detection aperture is increased to measure larger apertures and complex surface shapes, then the measurement capability is improved, but the lateral resolution is compromised
Solution Approach 1:
The detection aperture is divided into multiple sub-apertures that can be independently controlled. By segmenting the aperture, the system can measure larger apertures while maintaining high lateral resolution through precise control of each sub-aperture's position and size. The adjustable shelves enable segmentation of the detection aperture into multiple regions for independent optimization.
Solution Approach 2:
The detection aperture is made dynamic and adjustable rather than fixed. The optical adjustable shelves allow real-time modification of the aperture configuration, enabling the system to adapt to different measurement requirements. This dynamic capability permits optimization of both measurement capability and lateral resolution by adjusting aperture parameters during operation.
2Device complexity
If a conventional fixed aperture is used, then the device structure is simple, but the lateral resolution decreases for large-diameter apertures
Solution Approach 1:
The fixed aperture is replaced with a dynamic, adjustable aperture system. The optical adjustable shelves provide controlled movement and positioning capabilities, transforming the static aperture into a dynamic component. This enables the system to maintain high lateral resolution for large-diameter apertures while managing device complexity through structured adjustability.
Solution Approach 2:
The aperture system is segmented into controllable sub-regions through the adjustable shelves. This segmentation allows independent optimization of different aperture zones, maintaining high resolution across the entire large-diameter aperture while organizing the increased complexity into manageable segments.
3Area of stationary object
If the aperture size is increased to detect larger surfaces, then the measurement range is improved, but the lateral resolution is reduced
Solution Approach 1:
The detection aperture is segmented into multiple sub-apertures with independent position control. This segmentation enables the system to cover larger measurement areas while maintaining high lateral resolution through precise control of each segment's contribution to the overall measurement.
Solution Approach 2:
The system adds positional and configurational dimensions to the aperture control. By introducing adjustable shelves that provide position and orientation control, the system transforms the simple aperture area into a multi-dimensional control space, enabling large measurement range with maintained resolution through sophisticated positioning.
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 approach enables improved lateral resolution and the ability to measure complex surface shapes with larger apertures, effectively addressing the limitations of existing technologies by allowing for precise surface shape detection with enhanced precision.
Implementation Method 1
utilizing a diffraction of a pinhole to generate an ideal reference spherical wave
Implementation Method 2
the interference fringe of the two light beams is obtained on the detector (CCD)
Data Source
AI summary
The present disclosure provides detection devices and methods using a diffraction wavefront of a pinhole stitching measurement of surface shape. The light emitted from the laser passes through a filter hole, a first condenser lens, a spatial filter, a beam expander, a half wave plate, a λ/4 wave plate, an attention plate and then is transmitted through a beam splitter, reflected by a reflecting mirror and is irradiated onto an pinhole through a first optical adjustable shelf and a second set of condenser lens. A part of diffraction light generated by the pinhole is irradiated to the mirror to be measured; the light reflected by the mirror to be measured is reflected by a frame of the pinhole and generate a diffraction fringe along with another part of the diffraction wavefront of the pinhole. The interference fringe is focused by the third set of condenser lens on the third optical adjustable shelf and is collected by the CCD detector. The mirror to be measured is positioned on the second optical adjustable shelf and may be moved along a normal direction of the mirror to be measured to implement an annular aperture stitching measurement. Meanwhile, the first optical adjustable shelf may be rotated and moved in translation to measure the mirror by a scanning sub apertures stitching measurement.