Picosecond supercontinuum light source for stroboscopic white-light interferometry with freely adjustable pulse...

Area of Science:

• Optics and Photonics
• Materials Science
• Mechanical Engineering

Background:

• Characterizing high-frequency vibrations in microelectromechanical systems (MEMS) is crucial for performance evaluation.
• Existing methods may lack the resolution or bandwidth to accurately measure GHz-range vibrational fields.
• Stroboscopic white-light interferometry offers non-contact, high-resolution surface measurement capabilities.

Purpose of the Study:

• To develop a novel picosecond supercontinuum light source optimized for stroboscopic white-light interferometry.
• To enable high-resolution characterization of vibrational fields in electromechanical components up to the GHz range.
• To demonstrate the source's capability by measuring the vibration of a MEMS resonator.

Main Methods:

• A gain-switched laser diode was amplified in a two-stage fiber amplifier.
• Supercontinuum generation was achieved using a microstructured optical fiber.
• The generated picosecond pulses (duration < 310 ps) were utilized for stroboscopic illumination in a white-light interferometer setup.

Main Results:

• The developed light source produced optical pulses with optimized spectral properties and durations below 310 ps.
• Freely adjustable repetition rates were achieved for stroboscopic illumination.
• The system successfully characterized the surface vibration field of a silicon MEMS resonator at 3.37 MHz, reaching a minimum detectable vibration amplitude of less than 100 pm.

Conclusions:

• The picosecond supercontinuum light source is suitable for high-resolution stroboscopic white-light interferometry.
• The source enables GHz-range vibration analysis in electromechanical components.
• The demonstrated sensitivity of < 100 pm highlights its potential for advanced MEMS characterization.