Surface profiling by means of double spectral modulation.

Area of Science:

• Optics and Photonics
• Metrology
• Surface Science

Background:

• Interferometric profilometry is crucial for high-precision surface measurement.
• Traditional methods often require complex setups and piezoelectric transducers for phase shifting.
• Analyzing remote surfaces presents unique challenges in optical metrology.

Purpose of the Study:

• To propose a novel interferometric profilometry method utilizing double modulation of light.
• To demonstrate high-precision surface profile measurement with simplified instrumentation.
• To enable adaptable analysis of remote surfaces, including through optical fibers.

Main Methods:

• Double modulation of a light beam's power spectral distribution in both frequency and intensity.
• Leveraging frequency modulation by path difference in interferometry.
• Utilizing intensity modulation by object transparency in a spectroscopic device.

Main Results:

• Achieved high-precision surface profile measurement.
• Demonstrated automatic phase shifting via continuous wavelength variation, eliminating the need for piezoelectric transducers.
• Showcased adaptability for remote surface analysis via optical fibers.

Conclusions:

• The proposed double modulation technique offers a precise and simplified approach to interferometric profilometry.
• The method's inherent phase shifting mechanism enhances its practical applicability.
• Its adaptability through optical fibers broadens its potential use in various metrology applications.