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Improved phase-measuring deflectometry for aspheric surfaces test.
Applied Optics
|March 15, 2016
Summary
This study introduces an improved phase-measuring deflectometry (PMD) for testing aspheric surfaces. The novel method simplifies measurements by focusing on reflected rays, offering a new quantitative tool for optical manufacturing.
Area of Science:
- Optical Engineering
- Metrology
- Surface Testing
Background:
- Accurate measurement of aspheric surfaces is crucial for advanced optical systems.
- Traditional phase-measuring deflectometry (PMD) methods can be complex, requiring calibration or approximations for incident rays.
Purpose of the Study:
- To present an improved phase-measuring deflectometry (PMD) technique for efficient and quantitative testing of aspheric surfaces.
- To simplify the measurement process by eliminating the need for incident ray determination.
Main Methods:
- The improved PMD method is explored by reversing the principles of the Ronchi test.
- A camera aperture is positioned near the center of curvature of the test mirror.
- Fringes displayed on an LCD screen are reflected off the aspheric surface and captured by the camera.
Main Results:
- Analysis of captured fringes allows for the determination of deviations from the ideal shape.
- The aspheric surface under test is successfully reconstructed.
- Computer simulations and preliminary experiments validate the improved PMD's effectiveness.
Conclusions:
- The improved PMD offers a simplified approach to aspheric surface metrology.
- This method requires only the determination of reflected rays, bypassing complex calibration steps.
- It provides a new, quantitative, full-field measurement tool for optical manufacturing.
