Ronchi and Moiré patterns for testing spherical and aspherical surfaces using deflectometry

Area of Science:

• Optical testing and metrology
• Wavefront analysis
• Aberration measurement

Background:

• The Ronchi test is a common method for optical surface testing.
• Moiré deflectometry offers an alternative approach to wavefront analysis.
• Accurate measurement of optical aberrations is crucial for system performance.

Purpose of the Study:

• To compare the efficacy of the Ronchi test and Moiré deflectometry.
• To introduce and evaluate a new pattern: the Moiré-Ronchigram.
• To assess the precision of Zernike aberration coefficient determination.

Main Methods:

• Generating a novel Moiré-Ronchigram pattern by superposing two Ronchigrams.
• Applying both Ronchi test and Moiré deflectometry to mirror wavefronts.
• Calculating Zernike aberration polynomial coefficients for wavefront reconstruction.

Main Results:

• The Moiré-Ronchigram pattern was successfully created and utilized.
• Moiré deflectometry yielded Zernike coefficients with lower dispersion than the Ronchi test.
• Results were validated against established software (Open Fringe, FringeXP, APEX) using RMS and standard deviation.

Conclusions:

• Moiré deflectometry, particularly with the Moiré-Ronchigram, offers enhanced precision for Zernike aberration analysis.
• The Moiré-Ronchigram serves as a reliable pattern for optical testing.
• The findings support the use of Moiré deflectometry for accurate wavefront characterization.