Ablation, Dissection, and Transport of Biomaterials using Fs and Ns Laser Pulses

Fs laser nanosurgery is characterized by the formation of low-density plasma followed by chemical effects of the free electrons (bond breaking), thermal effects, and compressive and tensile thermoelastic stress waves that produce transient cavitation bubbles. Dissection using oscillator pulse trains at >> 1 MHz is usually performed at energies well below the bubble formation threshold and thus mediated by accumulative free-electron-induced chemical decomposition, possibly in conjunction with multiphoton-induced chemistry. By contrast, dissection with < 1 MHz repetition rate uses ≈10-fold larger pulse energies and relies on thermoelastic formation of minute transient cavitation bubbles ranging in size from ≈ 100 nm up to a few micrometers.