Medikal uygulamalar için fotonik bant yapılı içi boş fiberler

The design, fabrication and characterization of photonic band gap (PBG) basedoptical polymer fibers is discussed. Unlike conventional total internal reflection(TIR) fibers, used primarily in telecommunications, PBG fibers can be madehollow core and can be used to guide infrared radiation of any wavelength, aproperty known as wavelength scalability. Since the electromagnetic radiation istransmitted in the hollow core of the fiber, the intrinsic absorption of the fibercore as well as the insertion Fresnel losses at front and end faces are avoided,giving rise to extraordinarily high power densities to be delivered.The fiber production line includes material characterization, and the designof nanoscale quarter wavestacks using common thermoplastic polymers (polyether sulphone and poly ether imide) and chalcogenide glasses (As2S3, As2Se3,Ge15As25Se15Te45). The fiber preform is fabricated using rolling mechanism ofthermally evaporated chalcogenide glasses on large area polymers. Subsequently,the fiber preforms are thermally drawn to obtain nano-structured PBG fibers.Two different fibers are designed and produced, signifying wavelength scalabilityof the overall process, for the widely used holmium (Ho:YAG) and carbondioxide (CO2) medical lasers. The transmission characteristics of the fibersproved that they can be used to safely deliver 15Wlaser power, along a 3 meterfiber with external diameter of 1.5 mm and hollow core diameter of 0.5 mm,corresponding to a laser power density of 1kW/cm2 with a loss of -10dB/m.The PBG fibers are expected to be widely used in high precision surgicallaser for incision, photoablation and coagulation where infrared radiation is theradiation of choice for its superior laser-tissue interaction properties.