Abstract: A device for testing the light power output of an optical system comprises a thermochromic element, a body element optionally providing collimation or other means of reproducible positioning, and optionally filters and attenuation. A preferred device fits onto the end of an optical power delivery system, and the thermochromic element changes color if the system output is above a defined threshold. An alternative device provides a flat target with a The device may be adapted to be sterilizable, and may be disposable. Optional means for ensuring that the light delivery system is operational during the measurement are provided.

Abstract: An optical fiber device includes a polymeric optical fiber having a proximal end for coupling to a source of light, and a diffusing region. The polymeric optical fiber includes a core and a cladding around the core. The diffusing region includes a length of the polymeric optical fiber in which the cladding is partially removed to expose the core and in which the exposed core and the remaining cladding have a roughened surface for outwardly diffusing light carried through the polymeric optical fiber. The diffusing region is preferably formed by abrasion, for example by directing a particle jet at the optical fiber while rotating and translating the optical fiber with respect to the particle jet. The particle jet may include microscopic glass beads which roughen the optical fiber core. The density of scattering sites may be varied along the length of the diffusing region to produce a desired light output pattern.

Abstract: An angioplasty system and method for identification and laser ablation of atherosclerotic plaque at a target site in a blood vessel includes fluorescence analysis for identification of noncalcified plaque and calcium photoemission analysis for identification of calcified plaque. Calcified plaque is identified by time domain analysis of calcium photoemission. A high energy pulsed ultraviolet laser can be used for stimulation of fluorescence and for stimulation of calcium photoemission. The system is capable of distinguishing between calcium photoemission and a defective condition of optical fibers that are used to deliver laser energy to the target site. In an another embodiment of the angioplasty system, calcium photoemission is identified during a nonablative initial portion of the laser ablation pulse. When calcium photoemission is not identified, the laser ablation pulse is terminated during the initial nonablative portion thereof.