Abstract

Ultrashort mid-infrared pulses play a pivotal role in many applications including strong field physics. Optical parametric amplification (OPA) is one of the most commonly used methods to achieve such pulses. Supercontinuum generation (SCG) plays a key role as the seed source, in OPA systems. Generating SC in bulk using 2 pm lasers, such as thulium or holmium- based lasers, is not an easy task, due to the long pulse duration of such systems. A single mode fiber would be a more suitable nonlinear medium to produce a SC pulses because of their low threshold for SCG and their excellent spatial coherence. Recently, the low absorption of fluoride fibers, such as ZrF4-BaF2-LaF3- AlF3-NaF (ZBLAN) fibers, at the MIR region has introduced them as a great candidate for MIR-SCG applications. In this work, using only 0.5 pJ, 2 pm pulses generated in a thulium-based regenerative amplifier, we have generated, to the best of our knowledge, the first polarized supercontinuum in a ZBLAN fiber. The intensity and phase of the supercontinuum have been characterized by using sum-frequency generation (SFG) cross-correlation frequency-resolved optical gating (XFROG) to investigate how suitable the SC from the polarization- maintained ZBLAN (PM-ZBLAN) fiber is for an OPA seed pulse.

© 2019 Japan Society of Applied Physics, The Optical Society (OSA)