Single-polarization Single-mode Photonic Crystal Fiber

Polarization-maintaining fibers (PMFs) have been widely applied in telecommunication, optical fiber gyro, optical fiber hydrophone, fiber optic sensor, and other region. As a new kind of PMFs, Polarization-maintaining photonic crystal fiber (PM-PCF) has shorter beat length and higher birefringence than the conventional PMFs and has higher thermal stability and special structure. In particular, the single-polarization single-mode photonic crystal fiber is attracting more attention for its advantages such as single-polarization propagation and free polarization mode dispersion, which has become a focus in recent years.In the paper, the development and the advantages of PM-PCF are first presented. The analytical and numerical methods used in this thesis are introduced. Especially, the full-vector finite-element mathematical model is discussed in detail. Using this method, the effect of the PM-PCF structure on the optical characteristic parameters, including modal field diameters, effective refractive index of space-filling mode, normalized frequency, mode field and single-polarization single-mode region etc., are studied systemly. Two kinds of single-polarization single-mode H-K9L fibers at 1.31μm and 1.55μm are designed and analyzed. The broad single-polarization single-mode (SPSM) region in these fibers can be achieved by the simulated results. Finally, the thermal effect of PM-PCF lasers and the impaction of thermal effect upon polarization are analyzed. The birefringence of the stress-inducing PM-PCF laser decreases with thermal load increasing is exhibited.