Applications of Highly-Nonlinear Chalcogenide Glass Devices Tailored for High-Speed All-Optical Signal Processing

Abstract

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> Ultrahigh nonlinear tapered fiber and planar rib Chalcogenide waveguides have been developed to enable high-speed all-optical signal processing in compact, low-loss optical devices through the use of four-wave mixing (FWM) and cross-phase modulation (XPM) via the ultra fast Kerr effect. Tapering a commercial <formula formulatype="inline"><tex> $\hbox{As}_{2}\hbox{Se}_{3}$</tex> </formula> fiber is shown to reduce its effective core area and enhance the Kerr nonlinearity thereby enabling XPM wavelength conversion of a 40 Gb/s signal in a shorter 16-cm length device that allows a broader wavelength tuning range due to its smaller net chromatic dispersion. Progress toward photonic chip-scale devices is shown by fabricating <formula formulatype="inline"> <tex>$\hbox{As}_{2}\hbox{S}_{3}$</tex></formula> planar rib waveguides exhibiting nonlinearity up to <formula formulatype="inline"><tex>$2080\, {\rm W}^{-1}\cdot \hbox{km}^{-1}$</tex></formula> and losses as low as 0.05 dB/cm. The material's high refractive index, ensuring more robust confinement of the optical mode, permits a more compact serpentine-shaped rib waveguide of 22.5 cm length on a 7-cm-size chip, which is successfully applied to broadband wavelength conversion of 40–80 Gb/s signals by XPM. A shorter 5-cm length planar waveguide proves most effective for all-optical time-division demultiplexing of a 160 Gb/s signal by FWM and analysis shows its length is near optimum for maximizing FWM in consideration of its dispersion and loss. </para>