Fabrication of Polarization-Maintaining Photonic Crystal Fiber Coupler with Air Hole State Control Using CO_2 Laser Irradiation Technique

摘要

Polarization-maintaining photonic crystal fiber couplers (PM-PCFCs) were fabricated using a CO_2 laser irradiation technique. We could control the states of air holes in the tapered region of couplers by adjusting the laser power density in the fusion and the elongation processes. It was demonstrated that the air hole remaining PM-PCFC exhibited polarization-splitting characteristics and that the air hole collapsed PM-PCFC had polarization insensitive coupling characteristics.