We aim to design, fabricate, and test multi-material fibers that incorporate highly nonlinear chalcogenide glasses for generation of mid-infrared (MIR) coherent radiation via third-order and second-order nonlinear optical interactions. Fiber preforms that incorporate new fiber designs will be fabricated by extrusion and drawn into fibers optimized to produce supercontinuum radiation that covers the entire mid-infrared spectrum.
Intellectual merit: The proposed research integrates several areas of engineering and applied science including nonlinear optics, optical fibers, and material science. The success of the project rests on the resolution of several long-standing problems at the intersection of these fields (incorporation of multiple widely diverse materials in the same fiber, dispersion engineering in chalcogenide glass fibers, amongst others) and will thus foster future research in MIR nonlinear optics and parametric interactions in chalcogenide glass fibers.
Broader Impacts: The project will engender for inter-disciplinary research to be carried out with a team of graduate and undergraduate students in a unique setting. Upon success, this project will have a transformative effect on the field of MIR spectroscopy and imaging. It will allow spectroscopists, for example, to pursue high-resolution MIR spectroscopy at high brightness levels not afforded by traditional incoherent (thermal) MIR sources. The MIR is particularly important in spectroscopy for molecular spectral finger-printing, and the availability of a high-brightness coherent wide-spectrum fiber-based source will allow for new modalities of spectroscopic imaging where spatial resolution is combined with spectral and temporal discrimination (as would be advantageous, for example, in Raman microscopy).
" PI: Prof. Ayman Abouraddy, CREOL, The College of Optics & Photonics, University of Central Florida Period : 04/15/2010 – 04/14/2014 In the course of this project, we have developed a new generation of multimaterial infrared fibers thermally drawn from a macroscopic ‘preform’ that make use of the advantageous optical properties of chalcogenide glasses, while relying on robust thermoplastic polymers for the mechanical stability of the fibers. This success was first enabled by developing multiple techniques for extruding a fiber preforming from bulk chalcogenide glass and polymer, as shown in Fig. 1. Using such extruded rods, we may prepare preforms suitable for thermal drawing into a continuous fiber conveniently in an ambient atmosphere (Fig. 2). The built-in polymer jacket lends robustness to the drawn fiber and simplifies the drawing process. While chalcogenide fibers are typically quite fragile, the multimaterial fibers produced here are remarkably robust, as shown in Fig. 3. Indeed, even a tapered fiber in which the core diameter is reduced to 500 nm remains mechanically robust and may be easily manipulated and handled in the course of an optical experiment. This new generation of optical fibers offers many advantages in terms of the optical performance. Since the core diameter, core-cladding diameter ratio, and core-cladding index contrast are all readily controllable in our fabrication methodology (Fig. 4), the optical performance may be engineered. Specifically, the optical dispersion and nonlinearities may be designed to produce broadband supercontinuum radiation across the entire infrared spectrum. These fibers are expected to have impact on infrared applications such as delivery of quantum cascade laser light and remote sensing.
