9361755 Manasson Physical Optics Corporation (POC) proposes to develop a novel high- power, low-loss, hollow-fiber waveguide for the delivery of C02 laser energy. The waveguide's cladding will be made of materials with refractive index n << 1 in the CO2-laser (10.6 micron) wavelength band. A unique feature of the proposed approach is that the optical properties of the cladding material can be easily varied because of the nature of the materials employed. Thus, by slightly changing material composition, the operating wavelength of such fibers can be "tuned," making this a generic technology with broad applicability to the transmission of IR energy from any source. According to POC's preliminary ca1culations, the proposed design will result in a fiber having transmission losses that are orders of magnitude lower, at 10.6 microns, than the lowest losses reported for other fibers. It is at this wavelength that we propose to first demonstrate this technology. ***