Deep-UV lasers are especially good at ablating eye tissue and make excellent surgical tools, but due to the lack of a fiber-optic delivery system are currently limited to extraocular use. Scientists from the University of Western Australia (Perth, Australia) and Fudan University (Shanghai, China) have now created just such a delivery system intended for intraocular surgery. A hollow glass taper launches deep-UV light into a 200-μm-diameter pure-silica fiber core with fluorine-doped silica cladding. The light can be delivered into an eye or into tissue submerged in fluid.
Pulsed light from an Nd:YAG laser was frequency quadrupled to 266 nm and quintupled to 213 nm for the experiment. A standard fiber was tested against two modified fibers: a hydrogen-loaded version and another version with proprietary alterations (all fibers were greater than 500 mm in length). Lesions were generated in pig retinas for test purposes. At 266 nm, the maximum fluence was 8.4 J/cm2 and did not decrease over time for any of the fibers. At 213 nm, the fluence reached 1.4 J/cm2 through the modified fibers and was less in the standard fiber; the transmission efficiency decreased as a function of number of pulses (for example, from 1.04 to 0.60 J/cm2 for 1000 pulses). Contact Joe Miller at [email protected].
John Wallace | Senior Technical Editor (1998-2022)
John Wallace was with Laser Focus World for nearly 25 years, retiring in late June 2022. He obtained a bachelor's degree in mechanical engineering and physics at Rutgers University and a master's in optical engineering at the University of Rochester. Before becoming an editor, John worked as an engineer at RCA, Exxon, Eastman Kodak, and GCA Corporation.