Thierry Taunay

Multicore, tapered optical fiber for nonlinear pulse reshaping and saturable absorption.

We present a new method to create a coupled waveguide array via tapering a seven-core telecommunications fiber. The fiber based waveguide array is demonstrated to exhibit the novel physics associated with coupled waveguide arrays, such as discrete diffraction and discrete self-focusing. The saturable absorber characteristics of the device are characterized and an autocorrelation measurement reveals significant single-pass pulse reshaping.

Optical limiting properties of nonlinear multimode waveguide arrays

An experimental investigation of the transmission of multimode capillary waveguide arrays containing a liquid nonlinear absorber shows an enhanced nonlinear response relative to that found in a single waveguide and to the same length of bulk material. Comparison of the nonlinear response of arrays with different pitch to diameter (d/Lambda) ratios confirm that both the intensity distribution within an individual waveguide and coupling between the elements of the array influence the overall nonlinear response.

Optical limiting in solid-core photonic crystal fibers

Optical limiting in solid-core photonic crystal fibers filled with reverse-saturable absorbers has been observed. A sharp change in limiting threshold was found for materials in the fiber holes with refractive indices near n = 1.44.

Wavelength-selective core-to-jacket coupling in optical fiber

Mode coupling between the fundamental core mode of an as-drawn optical fiber operating far from cutoff and higher-order modes in the plastic jacketing has been observed. In one fiber, the transmission spectrum of the core exhibited five distinct minima between 1200 and 1900 nm. By approximating the fiber jacket as an asymmetric slab waveguide of infinite lateral extent, the wavelengths of these transmission features were successfully predicted using coupled-mode theory. Since conditions at the jacket surface influence the transmission spectrum, this coupling effect potentially enables new applications for environmental sensing.

Stress-dependent growth kinetics of ultraviolet-induced refractive index change and defect centers in highly Ge-doped SiO2 core fibers

The evolution of the index change of type-IIa gratings observed in 28 mol % Ge–SiO2 core fibers with 1.8 μm core diameter under various strains was measured from the optical spectra, and the induced defects at high and low strains were studied with electron spin resonance. Data will be presented to show that the index modulation (Δnmod) of type-IIa gratings is likely associated with Ge E′ centers.

Multi-core, tapered fiber for nonlinear pulse reshaping

We present a new method to create a coupled waveguide array via tapering a multi-core telecommunications fiber. This device exhibits the novel physics associated with coupled waveguide arrays: Discrete self-focusing and nonlinear pulse chopping.

Tension Effects on the Growth Kinetics of Fiber Bragg Gratings in Photosensitive Ge-SiO 2 Fibers

The effect of strain on the growth kinetics of the index modulation of fiber Bragg gratings (FBGs) and paramagnetic defect centers in Ge-SiO2 photosensitive fibers are reported.