Photoacoustic monitoring of the mass removed in pulsed laser ablation

The mass Δm removed per pulse in laser ablation was shown to correlate with the acoustic signal A and the beam diameter ϕ. The functional forms of Δm(A, ϕ) were deduced for aluminum and polyvinyl chloride, for fluence ranging from 1.5 through 88 J cm− 2. Δm so computed agreed with empirical values within experimental error. For samples whose mass is sensitive to environmental factors, off-line measurement of Δm was shown to be unreliable and real-time measurements such as acoustic monitoring became essential.