3D surface mapping of freeform optics using wavelength scanning lateral shearing interferometry

Area of Science:

• Optical Engineering
• Metrology
• Nanotechnology

Background:

• Freeform optics offer superior performance but present significant metrology challenges.
• Accurate 3D surface measurement is crucial for the development and application of freeform optics.

Purpose of the Study:

• To present a new lateral shearing interferometer for 3D surface profile measurements of freeform optics.
• To achieve high-speed, high-resolution, large-departure, and large-field-of-view measurements.

Main Methods:

• Development of a lateral shearing interferometer variant.
• Integration of a tunable laser source for enhanced measurement capabilities.
• Verification through comparison with existing techniques and measurement of a representative freeform optic.

Main Results:

• The proposed interferometer enables high-speed 3D surface profile measurements.
• Achieved high vertical resolution, large departure, and large field-of-view.
• Measurement results validated against established methods.

Conclusions:

• The novel lateral shearing interferometer is a viable and effective tool for freeform optics metrology.
• This technique advances the capabilities for characterizing complex optical surfaces.
• Offers potential for broader adoption in optical manufacturing and research.