Optical delivery device with high numerical aperture curved waveguide

摘要

An optical delivery device includes an optical fiber that receives an output beam of light from a light source such as a laser. The optical fiber includes a linear section, defining a longitudinal axis, and a curved distal end, with a curvature sufficient so that total internal reflection of the light around a bend is maintained and bending losses within the curved distal end are minimized. The curved distal end has a distal output tip that delivers substantially all of the output beam in a defined lateral direction from the longitudinal axis. The numerical aperture of the curved distal end is larger than the numerical aperture of the light in the linear section. The numerical aperture of the curved distal end can be increased by removing the fiber cladding and replacing it with a lower index material. By placing the curved distal end in a hollow sealed tube the fiber is effectively clad with a material of refractive index similar to 1, which creates a very high numerical aperture curved waveguide structure and allows very small curvatures to be made without bending losses.