Solitonic supercontinuum of femtosecond mid-IR pulses in W-type index tellurite fibers with two zero dispersion wavelengths

S Kedenburg,D Nguyen,H Giessen,A Steinmann,D Rhonehouse,F Mörz,J Zong,A Chavez-Pirson,T Steinle

doi:10.1063/1.4958333

Abstract

We present a detailed experimental parameter study on mid-IR supercontinuum generation in W-type index tellurite fibers, which reveals how the core diameter, pump wavelength, fiber length, and pump power dramatically influence the spectral broadening. As pump source, we use femtosecond mid-IR pulses from a post-amplified optical parametric oscillator tunable between 1.7 μm and 4.1 μm at 43 MHz repetition rate. We are able to generate red-shifted dispersive waves up to a wavelength of 5.1 μm by pumping a tellurite fiber in the anomalous dispersion regime between its two zero dispersion wavelengths. Distinctive soliton dynamics can be identified as the main broadening mechanism resulting in a maximum spectral width of over 2000 nm with output powers of up to 160 mW. We experimentally demonstrated that efficient spectral broadening with considerably improved power proportion in the important first atmospheric transmission window between 3 and 5 μm can be achieved in robust W-type tellurite fibers pumped at long wavelengths by ultra-fast lasers.

Highlights

High-power single-mode fiber-based supercontinuum sources with extremely wide wavelength coverage are ideal sources for spectroscopy and metrology as well as for defense applications.[1]
The nonlinear spectral broadening behavior is dramatically influenced by the dispersion properties of the fibers with different core diameters, especially by the position of the second zero dispersion wavelengths (ZDWs) relative to the pump wavelength
The position of the second ZDW is shifted with increasing core diameter due to the altering strength of waveguide dispersion (see Fig. 1(b))

Summary

Introduction

High-power single-mode fiber-based supercontinuum sources with extremely wide wavelength coverage are ideal sources for spectroscopy and metrology as well as for defense applications.[1]. A further interesting material is tellurite glass with a one order of magnitude higher nonlinear refractive index compared to fused silica and an excellent optical transparency up to 5 μm.[5] tellurium oxide based glasses exhibit good mechanical robustness and chemical durability superior to that of chalcogenides and fluorides. They possess a high optical damage threshold[1] on the order of ∼15-20 GW/cm[2]

Methods

Results

Conclusion