Currently browsing: Pre-RWTH journal publications

Theoretical Study of Optical Rectification at Radio Frequencies in a Slot Waveguide

Abstract: We present a theoretical study of optical rectification (OR) at radio frequencies (RF). OR is a process by which a second-order nonlinear optical material can directly convert an optical field into an RF electric field. The combination of high-index

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Demonstration of a low VπL modulator with GHz bandwidth based on electro-optic 
polymer-clad silicon slot waveguides

Abstract: We demonstrate a near-infrared electro-optic modulator with a bandwidth of 3 GHz and a VπL figure of merit of 0.8 V-cm using a push-pull configuration. This is the highest operating speed achieved in a silicon-polymer hybrid system to date

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Design of transmission line driven slot waveguide
Mach-Zehnder interferometers 
and application to analog optical links

Abstract: Slot waveguides allow joint confinement of the driving electrical radio frequency field and of the optical waveguide mode in a narrow slot, allowing for highly efficient polymer based interferometers. We show that the optical confinement can be simply explained

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Silicon photonics: On-chip OPOs

Abstract: Optical parametric oscillators (OPOs) have now been realized in a CMOS-style process by exploiting nonlinear four-wave mixing. Such multiwavelength sources bring the prospect of ultrafast chip-to-chip optical data communications a step closer. J. Witzens, T. Baehr-Jones, M. Hochberg, On-chip

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High-Speed Near Infrared Optical Receivers Based on Ge Waveguide Photodetectors Integrated in a CMOS Process

Abstract: We discuss our approach to monolithic intergration of Ge photodectors with CMOS electronics for high-speed optical transceivers. Receivers based on Ge waveguide photodetectors achieve a sensitivity of −14.2 dBm (10−12 bit error rate (BER)) at 10 Gbps and 1550 nm. G. Masini, S.

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Optoelectronics: Coupling lasers using photonic crystals

Abstract: Large arrays of vertical laser sources need to emit a coherent output of light. This can be achieved through photonic crystals that mediate the interaction between the lasers in the array. J. Witzens and A. Scherer, Coupling lasers using

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Optically triggered Q-switched photonic crystal laser

Abstract: An optically triggered liquid crystal infiltrated Q-switched photonic crystal laser is demonstrated. A photonic crystal laser cavity was designed and fabricated to support two orthogonally polarized high-Q cavity modes after liquid crystal infiltration. By controlling the liquid crystal orientation

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Hybrid superprism with low insertion losses and suppressed cross-talk

Abstract: We demonstrate with the two-dimensional finite-difference time-domain method that an adiabatic transition in a superprism with an interface along the [1 2̅ ] direction enhances the transmission through the superprism to more than 90% (−0.5 dB) over the wavelength range 1.47–1.68

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Monolithic integration of vertical-cavity surface-emitting lasers with in-plane waveguides

Abstract: The ability to couple light from a vertical-cavity surface-emitting laser into a planar, on-chip waveguide creates new opportunities for achieving higher levels of integration and functionality. Here we propose to use a strong grating etched into a waveguide defined

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Liquid-crystal electric tuning of a photonic crystal laser

Abstract: An electrically tuned nematic liquid-crystal (LC) infiltrated photonic crystal (PC) laser is demonstrated. This PC laser represents an emerging class of nanoscale optical adaptive devices enabled by the convergence of nonlinear optical materials, electronics, and fluidics that promise increased

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