Femtosecond lasers (FSLs) have always been a promising technology, but to date they have been largely restricted to use in cutting-edge university and government laboratory research. However, FSLs may finally be ready to break out of the laboratory and head into the marketplace, with such potential applications as tattoo removal, eye and dental surgery, arterial plaque removal, and destruction of viruses, bacteria, or even cancer cells.
Conventional continuous-wave (CW) laser ablation relies on linear absorption of light, in which the photon wavelength matches a molecular energy resonance in the material. “This process is fundamentally thermal since the molecules vibrate like a mass on a spring, heat up, then melt, combust, or boil off,” says Adam Tanous, director of applications marketing for Raydiance Inc, a manufacturer of FSL systems based in Petaluma, California. Thus CW lasers often create thermal damage, which limits their usefulness in many potential applications.
In contrast, FSL...
