Efficient second harmonic generation in nanophotonic waveguides for optical signal processing

International audienceWe report very efficient second harmonic generation in membrane photonic crystal waveguide. The combination of absorption-free material and slow-light enhancement enables a large harmonic generation efficiency. A peak pump power of about 450 mW generates up to 45 lW peak second harmonic power over a broad spectral range. The signal is exploited to demonstrate optical performance monitoring of data at 42 Gb/s

Free-carrier-induced soliton fission unveiled by in situ measurements in nanophotonic waveguides

Solitons are localized waves formed by a balance of focusing and defocusing effects. These nonlinear waves exist in diverse forms of matter yet exhibit similar properties including stability, periodic recurrence and particle-like trajectories. One important property is soliton fission, a process by which an energetic higher-order soliton breaks apart due to dispersive or nonlinear perturbations. Here we demonstrate through both experiment and theory that nonlinear photocarrier generation can induce soliton fission. Using near-field measurements, we directly observe the nonlinear spatial and temporal evolution of optical pulses in situ in a nanophotonic semiconductor waveguide. We develop an analytic formalism describing the free-carrier dispersion (FCD) perturbation and show the experiment exceeds the minimum threshold by an order of magnitude. We confirm these observations with a numerical nonlinear Schrödinger equation model. These results provide a fundamental explanation and physical scaling of optical pulse evolution in free-carrier media and could enable improved supercontinuum sources in gas based and integrated semiconductor waveguides

An efficient all-optical gate based on photonic crystals cavities and applications

International audienceWe use two coupled photonic crystal cavities to build an all-optical gate. The control and the modulated signal are separated spectrally by about 10 nm. This device was uperated at a rate ranging from 1 to 10 GHz with maximum coupled average power of less than 1 mW in the control signal, which translates to about 100 fJ per control pulse

Efficient Second Harmonic Generation in Photonic Crystal Waveguides for Optical Performance Monitoring in the Full C- Band at 42.5 Gb/s

International audienceWe demonstrate 20 µW second harmonic generation in a photonic crystal waveguide. The collected signal has been used for optical performance monitoring of the chromatic dispersion and optical signal to noise ratio of a 42.5 Gb/s Return to Zero signal all over the C-band

Low insertion losses and high drop efficiency photonic crystal filter for advanced telecom modulation formats

International audienceA 2D photonic crystal 3-ports filter with 6 dB bus insertion losses and drop efficiency of 47 % is reported. Error-free operation with low penalty (<0.5 dB) for OOK and DQPSK modulation formats is demonstrated

Wavelength Division Demultiplexing and Cross-Talk Assessment of a Photonic Crystal Filter

International audienceWe report on the design, fabrication and characterization of a filter for demultiplexing in the wavelength division domain realized with a H0 cavity on a III-V photonic crystal (PhC) membrane. This device is single mode, the total insertion losses are about 10.5 dB, the drop efficiency is close to 40 % and the channel isolation can exceed 20 dB at 500 GHz. 28 Gbit/s NRZ wavelength demultiplexing shows less than 0.5 dB penalties. Cross talk measurements demonstrate less than 1 dB penalty when adjacent channels are spaced as closely as 235 GHz, demonstrating the good compatibility of this filter with LAN-WDM systems. Finally, 56 Gbit/s NRZ-DQPSK signal filtering is assessed revealing negligible penalty (< 0.5 dB)