Sub-two-cycle soliton self-compression in a tapered tellurite photonic crystal fiber

We design tellurite tapered photonic crystal fibers (PCFs) for broadband mid-infrared supercontinuum (SC) generation in the few-optical-cycle regime. We show that we can move the zero dispersion wavelength (ZDW) beyond 2 μm toward mid-IR wavelength region by tapering tellurite PCFs. We demonstrate the generation of sub-two-cycle soliton selfcompressed pulses from 200 fs to 19.1 fs and show more than one octave-spanning coherent SC, extending from 1675 to 3950 nm, generated in 8 mm-long tapered tellurite PCF with low input pulse energy of 1 nJ at 2.9 μm.