Single-beam interferometry of a thermal bump.

Area of Science:

• Optics and Photonics
• Materials Science
• Thermal Analysis

Background:

• Laser-induced thermal effects are crucial in material processing and optical device characterization.
• Accurate measurement of surface displacement and optical property changes is essential for understanding these effects.
• Existing methods can be sensitive to environmental noise and may not easily decouple different physical phenomena.

Purpose of the Study:

• To present a novel single-beam interferometric technique for measuring laser-induced thermal bumps.
• To independently determine the effects of ac change in optical reflectivity and surface displacement.
• To demonstrate the robustness of the technique against sample vibrations and thermal fluctuations.

Main Methods:

• Utilized a single-beam interferometer to measure thermal effects.
• Employed an intensity-modulated and focused laser beam to generate thermal bumps.
• Applied a phenomenological theory to fit experimental data and decouple optical reflectivity and surface displacement.
• Assessed the technique's insensitivity to vibrations and thermal path variations.

Main Results:

• Successfully measured thermal bumps using the described interferometric method.
• Independently quantified the ac change in optical reflectivity and surface displacement.
• Demonstrated that the technique is insensitive to sample vibrations.
• Showed robustness against optical path variations due to thermal fluctuations.

Conclusions:

• The developed single-beam interferometric technique provides a reliable method for characterizing laser-induced thermal effects.
• Independent determination of reflectivity changes and surface displacement enhances the understanding of material responses to laser irradiation.
• The technique's insensitivity to environmental noise makes it suitable for precise measurements in various conditions.