Fundamentals and prospects of ultra-short laser-radiation for material processing, surface analysis and medical applications

摘要

Ultra-short laser-radiation has initiated a new era for medical laser applications as well as for laser applications in high-precision material processing. Entirely new prospects, in particular, their use for surgical applications and nano-technololy, can be envisioned with ultra-short laser pulses, which are now available from pico- and femto-second laser systems. The development of broadband solid-state gain media opened new possibilities for ultra-short pulse generation. In particular, the development of all-solid-state ultra-short pulse devices promise to make such devices rigged and reduce their cost. Ultra-short laser light offers many advantages, as for instance low thermal damage and the possibility of efficient interaction of light with long wavelengths. Extremely high peak laser intensities, which can be achieved even with commercially available systems (typical values are 10~(15)W/cm~2 imply physical mechanisms, which reach beyond the "classical" model of (multi-) photon absorption as the principal energy transfer process. The consequences, as observed in, however still preliminary applications, result in many obvious advantages as for instance: efficient ablation; minimization of collateral damage; ablation thresholds and rates which are relatively insensitive to tissue type; high control over ablation depth, achievable because only a small amount of tissue is ablated per pulse.