Non-contact handpiece for laser tissue cutting

Abstract

A non-contact laser handpiece, contains optical components modified to provide a high density uniform later beam at a distance from the handpiece that minimizes effects of back reflection.

What is claimed is: 
     
         1 . An apparatus comprising:
 a laser handpiece housing;   a waveguide configured to provide a laser beam in the housing from a laser source; and   a first lens that is installable in an installed position in the housing, and that has:
 a first end surface configured to be, when in the installed position, located within the housing and through which the beam enters the elongated lens, and 
 an opposite second end surface configured to be, when in the installed position, located outside the housing and through which the beam exits the elongated lens, with at least one of the first and second end surfaces being convex to focus the beam at a tissue target location beyond the second end surface; 
   wherein the first lens is interchangeable with a second lens that differs from the first lens in terms of a converging characteristic and that is installable in an installed position in the housing to enable changing the converging characteristic by interchanging the first lens with the second lens, the second lens having a first end surface configured to be, when in the installed position, located within the housing and through which the beam enters the elongated lens, and an opposite second end surface configured to be, when in the installed position, located outside the housing and through which the beam exits the elongated lens, with at least one of the second lens's first and second end surfaces being convex to focus the beam at a tissue target location beyond the second end surface.   
     
     
         2 . The apparatus of  claim 1 , wherein the first lens is elongated, having a length defined by and between the lens's first and second end surfaces and a width that is smaller than the length. 
     
     
         3 . The apparatus of  claim 2 , wherein the length is about 2 mm to about 5 mm, and the width is about 1 mm to about 3 mm. 
     
     
         4 . The apparatus of  claim 2 , wherein the elongated lens is a structure of sapphire or glass. 
     
     
         5 . The apparatus of  claim 4 , wherein the structure includes a cylindrical portion. 
     
     
         6 . The apparatus of  claim 1 , wherein the first lens's first end surface is convex. 
     
     
         7 . The apparatus of  claim 1 , wherein the first lens's second end surface is convex. 
     
     
         8 . The apparatus of  claim 7 , wherein the first lens's first end surface is convex. 
     
     
         9 . The apparatus of  claim 7 , wherein the first lens's first end surface is not convex, and the beam is not converging throughout its path from the waveguide to the second end surface. 
     
     
         10 . The apparatus of  claim 1 , wherein the handpiece is configured for the beam to be diverging throughout the beam's path from the waveguide to the convex surface. 
     
     
         11 . The apparatus of  claim 1 , wherein the waveguide comprises an optical fiber, and the convex surface is configured to converge the beam to a diameter, at a waist of the beam, about the same as a diameter of the waveguide. 
     
     
         12 . The apparatus of  claim 1 , wherein the converging characteristic is a distance from the second end surface to a waist of the beam. 
     
     
         13 . The apparatus of  claim 1 , wherein the converging characteristic is a width of the beam at a waist of the beam. 
     
     
         14 . The apparatus of  claim 1 , wherein the converging characteristic is a cross-sectional shape of the beam at a waist of the beam. 
     
     
         15 . The apparatus of  claim 1 , wherein the converging characteristic is a power density of the beam at a waist of the beam.