Robust, motion-free optical characterization of samples using actively-tunable Twyman-Green interferometry

Area of Science:

• Optical metrology
• Interferometry
• Measurement science

Background:

• Optical interferometry is vital for measurement, imaging, and calibration.
• Conventional Twyman-Green interferometers often require bulk mechanical motion for sample characterization.
• Existing methods face limitations in miniaturization and automation.

Purpose of the Study:

• To present a novel actively-controlled optical interferometer.
• To enable bulk-motion-free characterization of transparent samples.
• To demonstrate the potential for miniaturizing interferometric devices.

Main Methods:

• Implementation of an actively-controlled tunable focus lens in the sample arm of a Twyman-Green interferometer.
• Characterization of transparent samples in cubical geometry.
• Experimental validation of the actively-tunable interferometer's performance.

Main Results:

• Successful characterization of various transparent samples.
• Demonstration of thickness and refractive index measurements without bulk mechanical motion.
• Excellent experimental results validating the proposed technique.

Conclusions:

• The actively-tunable interferometer eliminates the need for bulk motion in measurements.
• This innovation facilitates the miniaturization of Twyman-Green interferometers.
• The proposed technique offers enhanced capabilities for optical metrology applications.