Polarization maintaining highly nonlinear photonic crystal fiber for supercontinuum generation at 1.55μm

• Published in: Optics and laser technology Vol. 44; no. 5; pp. 1261 - 1269
• Main Authors: Hossain, M.A., Namihira, Y., Islam, M.A., Hirako, Y.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-07-2012
• Subjects: Finite element method (FEM); Polarization maintaining fiber (PMF); Supercontinuum (SC); Finite element method (FEM); Polarization maintaining fiber (PMF); Supercontinuum (SC)
• ISSN: 0030-3992; 1879-2545
• DOI: 10.1016/j.optlastec.2011.12.052

A polarization maintaining highly nonlinear Germanium (Ge) doped photonic crystal fiber (HNL-GePCF) is proposed for supercontinuum (SC) generation at 1.55μm as polarization maintaining properties in a fiber enhance nonlinear interactions to generate SC using less optical power. By designing 3% higher refractive index Ge-doped core with core ellipticity ϵ=0.9 inside silica, nonlinear coefficient γ and birefringence B are increased as large as 83W−1km−1 and 2.82×10−4 respectively at 1.55μm. Using finite element method (FEM) with a circular perfectly matched boundary layer (PML), it is shown through simulations that the proposed HNL-GePCF offers an efficient SC generation at 1.55μm. By propagating sech2 picosecond optical pulses having 2.5ps and 1.0ps pulsewidth at a full width at half maximum (FWHM) through the proposed HNL-GePCF, output optical pulses are analyzed by the split-step Fourier method to obtain the spectral contents. The highest 10dB bandwidth spectra at 1.55μm are observed as 100nm and 150nm for 2.5ps input optical pulse and for 1.0ps input optical pulse respectively.