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The Methods and Experiments of Shape Measurement for Off-Axis Conic Aspheric Surface
Shijie Li1,2, Jin Zhang1,2, Weiguo Liu1,2
1Shaanxi Province Key Laboratory of Thin Film Technology and Optical Test, Xi'an Technological University, Xi'an 710021, China.
Materials (Basel, Switzerland)
|May 7, 2020
Summary
This study validates three null test methods for precisely measuring off-axis conic aspheric surfaces. Experimental results confirmed the accuracy and effectiveness of auto-collimation, single computer-generated hologram (CGH), and hybrid compensation techniques.
Area of Science:
- Optical Engineering
- Metrology
Background:
- Off-axis conic aspheric surfaces are crucial components in advanced optical systems.
- Accurate shape measurement is essential during the optical processing of these surfaces.
Purpose of the Study:
- To present and detail three null test methods for measuring the shape accuracy of off-axis conic aspheric surfaces.
- To experimentally validate the effectiveness and consistency of these measurement techniques.
Main Methods:
- Auto-collimation null test.
- Single computer-generated hologram (CGH) null test.
- Hybrid compensation null test.
Main Results:
- Experimental measurements of an off-axis paraboloid (OAP) were performed using the three distinct null test methods.
- Peak-to-valley (PV), root-mean-square (RMS), and shape distribution results were consistent across all tested methods.
- The consistency confirmed the correctness and effectiveness of the employed measurement techniques.
Conclusions:
- The three presented null test methods (auto-collimation, single CGH, hybrid compensation) are effective for precise shape measurement of off-axis conic aspheric surfaces.
- The experimental validation demonstrates the reliability of these methods for engineering applications.
- Accurate metrology is critical for the successful implementation of aspheric optics in modern systems.
