Simulation of Infrared Photonic Crystal Fibers for Laser Medicine at a Wavelength of 10.6 µm

Infrared photonic-crystal fibers (IR PCF) based on AgCl
_x
Br
_1-x
and AgBr
_x
I
_1-x
crystals have been developed for operation at a CO
₂
laser wavelength (10.6 μm). The prospects of using fiber optics, including those with a photonic structure, in medical technologies as a conductor of laser radiation are considered. The advantages and disadvantages of unjacket and two-layer fibers, as well as the versatility and uniqueness of photonic crystal fibers are shown. The process of designing optical fibers with a photonic structure is presented, from the stages of mathematical and computer modeling to seven-stage extrusion and properties study. In computer simulations, plane wave and finite element methods were used to analyze the band structure and mode analysis, respectively. In the properties' study, a CO
₂
laser and a Spiricon Pyrocam III camera were used. The model was verified with a real fiber by measuring the radiation distribution in the far zone. High convergence of simulation results with the fabricated fiber is obtained. Thus, infrared fibers with an increased mode field diameter were obtained, which are flexible, easy to sterilize and safe for humans for medical applications.