A novel and simple all-hollow-waveguide lens-free system for mid-infrared CO/sub 2 /laser (10.6 /spl mu/m) delivery into precise tissue area is presented. It includes a grazing-incidence-based uncoated hollow glass taper for direct laser-to-waveguide coupling and a multilayer hollow delivery waveguide.

We demonstrate a novel dual-confocal fiber-optic technique for simultaneous refractive-index and thickness measurement. It is an intensity sensing, 2/spl times/2-fiber-coupler-based design that includes two identical fiber-optic confocal microscopes. The sensor technique provides high accuracy in spatially locating specific imaging points and biparameter measurements.

An in vivo animal model study of the optical properties and light transmission characteristics of single and multiple tissue layers and blood using either coherent or incoherent light sources in a broad spectral range covering the visible and near-infrared is presented.

A novel and simple noninvasive sensor technique for simultaneous measurement of refractive-index and thickness of both optically transparent and non-transparent media is presented. It is a fiber-optic confocal-microscope-type sensor technique based on either a single-confocal or a combined dual-confocal fiber-optic design. The single-confocal design is a single-fiber, intensity sensing arrangement that provides precise spatial location of the backreflecting sample surfaces and bi-parameter measurements. The combined dual-confocal design includes two independent confocal channels consisting of two identical apertureless fiber-optic-type confocal microscopes constructed by use of a single 2x2 fiber coupler. This sensor arrangement provides direct measurement in absolute unites of refractive-index and thickness of optically transparent and non-transparent media.