High-nonlinearity dispersion-shifted lead-silicate holey fibers for efficient 1-/spl mu/m pumped supercontinuum generation

Abstract

Abstract-This paper reports on the recent progress in the design and fabrication of high-nonlinearity lead-silicate holey fibers (HFs). First, the fabrication of a fiber designed to offer close to the maximum possible nonlinearity per unit length in this glass type is described. A value of γ = 1860 W −1 · km −1 at a wavelength of 1.55 µm is achieved, which is believed to be a record for any fiber at this wavelength. Second, the design and fabrication of a fiber with a slightly reduced nonlinearity but with dispersion-shifted characteristics tailored to enhance broadband supercontinuum (SC) generation when pumped at a wavelength of 1.06 µm-a wavelength readily generated using Yb-doped fiber lasers-are described. SC generation spanning more than 1000 nm is observed for modest pulse energies of ∼ 100 pJ using a short length of this fiber. Finally, the results of numerical simulations of the SC process in the proposed fibers are presented, which are in good agreement with the experimental observations and highlight the importance of accurate control of the zero-dispersion wavelength (ZDW) when optimizing such fibers for SC performance.

Progress in the Fabrication of the Next-Generation Soft Glass Microstructured Optical Fibers

“…The concept of small-core high-NA fibers with a core suspended in air via 3 fine struts was developed for highnonlinearity applications using high-index glasses [1][2][3]. We extended this concept to fibers for evanescent field based sensing, which requires low-index glasses to achieve a high power fraction of light in the air holes [7].…”

“…We extended this concept to fibers for evanescent field based sensing, which requires low-index glasses to achieve a high power fraction of light in the air holes [7]. We commenced the work on low-index glass suspended-core fibers using the same die design that has been employed successfully for high-index glass fibers of the same type [2,3]. We used commercially available lead silicate glass F2, which exhibits both low index and sufficiently low softening temperature to be used for preform extrusion.…”

“…For many nonlinearity applications, not only high nonlinearity but also good dispersion control is required. Suspendedcore fiber allows only limited dispersion tailoring via alteration of the core size, whereas an array of several air holes in the fiber cladding enables wider dispersion control via adjustment of both the hole pitch and the hole size [3]. Therefore, we explored fabrication of the latter fiber type for bismuth glass using a die exit structure corresponding to a haxagonal array of circular holes with relative hole size (i.e.…”

“…Recently, significant progress in the development of MOFs with extremely high nonlinearities using high-index soft glasses such as lead silicate, bismuth and tellurite [1][2][3] has been achieved. First high-nonlinearity fibers with dispersion control were demonstrated [3]. Further, large mode area (LMA) MOFs for high power delivery and generation in the near-infrared were demonstrated using phosphate and tellurite glass [4,5].…”

1.0.MU.m band supercontinuum light as WDM pulse source generated by using photonic crystal fibers

“…A PCF is also suitable as a nonlinear fiber for realizing spectral broadening in the 1.0 μm band, because PCF can provide high nonlinearity and low dispersion in the 1.0 μm band. There have been some reports describing supercontinuum generation in the 1.0 μm band using centimeter-and meter-long PCFs [4,5]. The reported broadened spectrum is not designed for WDM signal pulse generation and the repetition rates of the pulses used in these experiments are in the kHz to MHz region.…”