Brightened single-bubble sonoluminescence by phase-adjusted high-frequency acoustic pulse

Area of Science:

• Acoustics
• Fluid Dynamics
• Physical Chemistry

Background:

• Single-bubble sonoluminescence (SBSL) is a phenomenon involving light emission from collapsing bubbles.
• Controlling SBSL intensity is crucial for various applications, including imaging and spectroscopy.
• Previous studies have explored external stimuli to modulate SBSL.

Purpose of the Study:

• To investigate the effect of high-frequency acoustic pulses on the intensity of single-bubble sonoluminescence.
• To determine the optimal conditions for pulse application to maximize SBSL brightness.
• To validate experimental findings with numerical simulations.

Main Methods:

• Experimental setup using a polyvinylidene fluoride transducer to generate and superimpose a 10 MHz acoustic pulse onto an SBSL bubble.
• Measurement of SBSL intensity as a function of the time lag between the acoustic pulse and the bubble collapse cycle.
• Numerical simulation using the Rayleigh-Plesset equation to model bubble dynamics under acoustic forcing.

Main Results:

• A high-frequency acoustic pulse, when applied at the early growing stage of the bubble, significantly increases SBSL intensity.
• The maximum increase in brightness reached 300% compared to classical SBSL.
• Numerical calculations confirmed the experimental observation that precise timing of the pulse is essential.

Conclusions:

• Superimposing a high-frequency acoustic pulse at the correct time during bubble growth is an effective method to enhance single-bubble sonoluminescence.
• The findings provide a method for controlled intensification of SBSL.
• This research offers insights into the dynamics of bubble behavior under acoustic influence.