Patent · US Expired

Ultrashort pulse high repetition rate laser system for biological tissue processing

US5720894A · kind A · utility

461Cited by
15References
21Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJan 11, 1996
Grant dateFeb 24, 1998
Priority date
Expiry dateJan 11, 2016

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB23K2103/50
  • WIPO fieldMachine tools
  • WIPO sectorMechanical engineering

Abstract

A method and apparatus is disclosed for fast, efficient, precise and damage-free biological tissue removal using an ultrashort pulse duration laser system operating at high pulse repetition rates. The duration of each laser pulse is on the order of about 1 fs to less than 50 ps such that energy deposition is localized in a small depth and occurs before significant hydrodynamic motion and thermal conduction, leading to collateral damage, can take place. The depth of material removed per pulse is on the order of about 1 micrometer, and the minimal thermal and mechanical effects associated with this ablation method allows for high repetition rate operation, in the region 10 to over 1000 Hertz, which, in turn, achieves high material removal rates. The input laser energy per ablated volume of tissue is small, and the energy density required to ablate material decreases with decreasing pulse width. The ablation threshold and ablation rate are only weakly dependent on tissue type and condition, allowing for maximum flexibility of use in various biological tissue removal applications. The use of a chirped-pulse amplified Titanium-doped sapphire laser is disclosed as the source in one embod…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.