692 research outputs found

    Coarse wavelength division multiplexer on silicon-on-insulator for 100 GbE

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    A four-channel cascaded MZl based de-multiplexer at O-band with coarse channel spacing of 20 nm and band flatness of 13 nm is demonstrated on silicon-on-insulator. The device shows a mean crosstalk and insertion loss below -16 dB and 2.5 dB

    Germanium-on-silicon mid-infrared waveguides and Mach-Zehnder interferometers

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    In this paper we describe Ge-on-Si waveguides and Mach-Zehnder interferometers operating in the 5.2 - 5.4 mu m wavelength range. 3dB/cm waveguide losses and Mach-Zehnder interferometers with 20dB extinction ratio are presented

    Room temperature InGaAs/InP distributed feedback laser directly grown on silicon

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    We report an optically pumped room-temperature O-band DFB laser, based on the buffer-less epitaxial growth of high quality InGaAs/InP waveguides directly on silicon wafer

    Carrier lifetime assessment in integrated Ge waveguide devices

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    Carrier lifetimes in Ge waveguides on Si are deduced from time-resolved pump-probe spectroscopy. For a 1 pm wide Ge waveguide, a lifetime of 1.6 ns is estimated for a carrier density of around 2 x10(19) cm(-3)

    Extraction of carrier lifetime in Ge waveguides using pump probe spectroscopy

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    Carrier lifetimes in Ge-on-Si waveguides are deduced using time-resolved infrared transmission pump-probe spectroscopy. Dynamics of pump-induced excess carriers generated in waveguides with varying Ge thickness and width is probed using a CW laser. The lifetimes of these excess carriers strongly depend on the thickness and width of the waveguide due to defect assisted surface recombination. Interface recombination velocities of 0.975 x 10(4) cm/s and 1.45 x 10(4) cm/s were extracted for the Ge/Si and the Ge/SiO2 interfaces, respectively. Published by AIP Publishing

    The diversification of national football teams

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    The inclusion of foreign-born sportspeople in national sports teams has become increasingly common. At the same time, the assumed increase in diversity within national football teams has turned into a major subject of (inter)national controversy and debate. This applies, in particular, to the football World Cup, as the assumed increase in foreign-born players in national football teams detracts from the (homogeneous) nation-state basis of the Fédération Internationale de Football Association’s (FIFA) international football competitions. However, the actual dynamics and complexities of the presence of foreign-born players in national football teams within this context have remained under-researched. In this paper, we use the idea of ‘migration corridors’ to examine the underlying structures that contribute to the diversification of national football teams, in particular during the World Cup. We do so from both an immigration and emigration perspective. By connecting our foreign-born player data to three types of migration corridors, we discuss the bidirectiona

    Compact thermally tunable silicon racetrack modulators based on an asymmetric waveguide

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    A compact wavelength-tunable 10-Gb/s silicon racetrack modulator with integrated thermo-optic heater is demonstrated by using a waveguide with an asymmetric cross section, combining the compact footprint of microdisk modulators with the design simplicity of regular racetrack or ring modulators. The outer perimeter of the asymmetric racetrack modulator is fully etched to maximize optical confinement, and the inner waveguide edge is shallowly etched to maintain an electrically conductive path to the embedded p-n diode and to control the propagation of the asymmetric optical mode and its coupling to the bus waveguide. The resistive heating elements based on highly doped Si strips are implemented at the outer edge of the modulator for thermo-optic control. The asymmetric modulators can be fabricated along with Si wire waveguides and shallowly etched fiber-grating couplers using a simple process flow involving just two Si-patterning steps. Devices with a bending radius of 10 mu m and a novel "T"-shaped p-n diode layout have been fabricated, and exhibit electro-optic modulation and heater efficiencies of 28 pm/V and 42 pm/mW, respectively. At 10 Gb/s, a stable extinction ratio of 10 dB is demonstrated from a 2V(pp) drive swing, which can be maintained over a wavelength range of 4.6 nm by thermally tuning the modulator. This is equivalent with a temperature variation of about 62 degrees C
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