Infrared tissue imaging at on-the-spot laser delivery using an all-optical-waveguide transmitting system

We present experimental results on mid-infrared thermal imaging of micro-scale tissue area irradiated by an all-optical-waveguide laser delivery system. The infrared transmitting system is based on a novel and simple laser delivery technique that includes two key optical elements: a grazing-incidence-based uncoated hollow taper used for direct infrared laser-to-fiber coupling, and a tissue-activated optical fiber probe with a specially shaped tip. The lens-free all-optical-waveguide transmitting system provides on-the-spot laser delivery into a precise micro-scale tissue area. When an Er:YAG (/spl lambda/=2.94 /spl mu/m) laser is used as a mid-infrared laser source, we obtain infrared thermal images from a small-size tissue area and a single hair.