Sweep Pulse Excitation Method for Enhancing Photoacoustic Elastic Waves at Different Laser Irradiation Parameters

Area of Science:

• Laser remote sensing
• Photoacoustics
• Non-destructive testing

Background:

• Resonance effects enhance photoacoustic elastic waves.
• Sweep pulse excitation detects natural frequencies, similar to hammering tests.
• This method can enable convenient, low-cost strength diagnosis of fastening bolts.

Purpose of the Study:

• Investigate the dynamics of sweep excitation for optimization.
• Evaluate laser irradiation conditions (pulse width, spot size, average power).
• Analyze effects on different metal disc samples.

Main Methods:

• Utilized sweep pulse excitation with laser remote sensing.
• Varied laser irradiation parameters: pulse width, spot size, average power.
• Tested on various metal disc samples to study photoacoustic elastic wave generation.

Main Results:

• Photoacoustic elastic wave magnitude is proportional to absorbed laser power.
• Spatiotemporal dynamics are explained by thermal diffusion.
• Optimized laser conditions enhance signal detection.

Conclusions:

• Sweep pulse excitation is effective for enhancing photoacoustic elastic waves.
• Findings contribute to the development of laser-sensing technology.
• Method shows potential for efficient and cost-effective structural health monitoring.