Broadband infrared supercontinuum generation in hexagonal-lattice tellurite photonic crystal fiber with dispersion optimized for pumping near 1560 nm.

We report on supercontinuum generation (SG) in a hexagonal lattice tellurite photonic crystal fiber (PCF). The fiber has a regular lattice with a lattice constant Λ = 2 μm, linear filling factor d/Λ = 0.75, and a solid core 2.7 μm in diameter. Dispersion, calculated from scanning electron microscope (SEM) image of drawn fiber, has zero dispersion wavelength (ZDW) at 1410 and 4236 nm with a maximum of 193 ps/nm/km at 2800 nm. Under pumping with 150 fs/36 nJ/1580 nm pulses, supercontinuum spectrum in a bandwidth from 800 nm to over 2500 nm was observed in a 2 cm long PCF sample, which is comparable to results reported for suspended core tellurite PCFs pumped at wavelengths over 1800 nm. Measured spectrum is analyzed numerically with good agreement, and observed spectral broadening is interpreted. To our best knowledge, tellurite glass, regular lattice PCFs for successful SG in this bandwidth have not been reported before.