Apparatus comprising an articulated arm radiation guide

Abstract

Articulated arm for guiding infrared radiation, with preferred wavelength between about 1 .mu.m and about 100 .mu.m, from a typically stationary radiation source to a moving or movable target. The inventive arm comprises hollow waveguides of the Marcatili-Schmeltzer type, with preferred bore diameter between about 50 and about 200 wavelengths of the radiation to be guided in the bore. Preferred waveguides consist of glass or quartz tubes of cylindrical cross section. The waveguides are typically held coaxially inside straight tubular members, the members being connected movably in end-to-end fashion. Beam direction altering means, for instance, reflecting means such as plane mirrors, serve to direct the radiation from the output end of one waveguide into the input end of the next waveguide. The articulated arm according to the invention typically is mode preserving, e.g., single mode radiation remains single mode, has high pointing accuracy, i.e., the direction of the output beam is substantially constant with respect to the axis of the output segment of the arm regardless of the spatial position or configuration of the arm. The arm can be designed to be mechanically light and higly maneuverable, and can be used in conjunction with a variety of output devices or probes. An exemplary probe useful, e.g., in transvitreal coagulation of retinal vessels, comprises hollow dielectric waveguides, including a tapered waveguide section. In addition to use in eye surgery and other surgical procedures, the inventive arm can advantageously be applied in such industrial processes as welding, soldering, cutting, annealing, scribing, drilling, and resistor trimming with infrared radiation.