Yvan Paquot

Phase-sensitive amplification of light in a χ(3) photonic chip using a dispersion engineered chalcogenide ridge waveguide.

We report phase-sensitive amplification of light using χ((3)) parametric processes in a chalcogenide ridge waveguide. By spectrally slicing pump, signal and idler waves from a single pulsed source, we are able to observe 9.9 dB of on-chip phase-sensitive extinction with a signal-degenerate dual pump four-wave mixing architecture in good agreement with numerical simulations.

Single parameter optimization for simultaneous automatic compensation of multiple orders of dispersion for a 1.28 Tbaud signal

We report the demonstration of automatic higher-order dispersion compensation for the transmission of 275 fs pulses associated with a Tbaud Optical Time Division Multiplexed (OTDM) signal. Our approach achieves simultaneous automatic compensation for 2nd, 3rd and 4th order dispersion using an LCOS spectral pulse shaper (SPS) as a tunable dispersion compensator and a dispersion monitor made of a photonic-chip-based all-optical RF-spectrum analyzer. The monitoring approach uses a single parameter measurement extracted from the RF-spectrum to drive a multidimensional optimization algorithm. Because these pulses are highly sensitive to fluctuations in the GVD and higher orders of chromatic dispersion, this work represents a key result towards practical transmission of ultrashort optical pulses. The dispersion can be adapted on-the-fly for a 1.28 Tbaud signal at any place in the transmission line using a black box approach.

Reconfigurable linear combination of phase-and-amplitude coded optical signals

We introduce an all-optical arithmetic unit operating a weighted addition and subtraction between multiple phase-and-amplitude coded signals. The scheme corresponds to calculating the field dot-product of frequency channels with a static vector of coefficients. The system is reconfigurable and format transparent. It is based on Fourier-domain processing and multiple simultaneous four-wave mixing processes inside a single nonlinear element. We demonstrate the device with up to three channels at 40 Gb/s and evaluate its efficiency by measuring the bit-error-rate of a distortion compensation operation between two signals.

All-optical hash code generation and verification for low latency communications

We introduce an all-optical, format transparent hash code generator and a hash comparator for data packets verification with low latency at high baudrate. The device is reconfigurable and able to generate hash codes based on arbitrary functions and perform the comparison directly in the optical domain. Hash codes are calculated with custom interferometric circuits implemented with a Fourier domain optical processor. A novel nonlinear scheme featuring multiple four-wave mixing processes in a single waveguide is implemented for simultaneous phase and amplitude comparison of the hash codes before and after transmission. We demonstrate the technique with single polarisation BPSK and QPSK signals up to a data rate of 80 Gb/s.

Breaking the Tbit/s Barrier: Higher Bandwidth Optical Processing

The growing demand for broadband communications has inspired many approaches to increasing capacity. Our recent work shows that combining linear and nonlinear optical signal processing can overcome some of the challenges faced by high-symbol rate signals.

Automatic higher-order dispersion measurement and compensation of a 1.28 Tbaud signal

We present the first automatic and simultaneous compensation of combined higher-order dispersion and GVD fluctuations of a 1.28 Tbaud signal using a photonic-chip based RF-spectrum analyser and a spectral pulse-shaper.

Terabaud optical sampling on a chalcogenide optical chip

We demonstrate terabaud optical sampling by combining four-wave mixing in a chalcogenide chip with a long wavelength carbon nanotube modelocked fiber laser. System resolution is 320 fs, 150 fs lower than previous systems.

Phase-sensitive amplification in a χ (3) photonic chip

Summary form only given. Four-wave mixing and other parametric nonlinear processes have been the subject of much research over the last decades. In particular phase sensitive amplification in optical parametric amplifiers holds great potential for signal processing in optical telecommunications, e.g. for the regeneration of phase encoded signals [1] or as potentially broadband, noiseless amplifiers [2].While there are some demonstrations of phase-sensitive amplification and regeneration in chip-like architectures based on the second-order χ(2) nonlinearity [3] in periodically-poled Lithium Niobate waveguides, most demonstrations thus far have been using highly nonlinear fibre with the associated limitations on bandwidth and integrability. In particular there has not been a demonstration of phase-sensitive amplification inside a χ(3)-based integrated platform such as Silicon or highly nonlinear glasses. In this submission we demonstrate for the first time phase-sensitive amplification inside a χ(3) photonic chip using a highly nonlinear chalcogenide waveguide. Our demonstration is based on an elegant spectral control technique that slices the pump and signal waves from the same broadband spectrum of a mode-locked laser, thus significantly simplifying the challenges of ensuring synchronization of the waves while enabling accurate control of the relative phase of the interacting waves.The experimental setup is depicted in Fig. 1(a). A mode-locked laser (repetition rate 38.6 MHz, 300 fs pulse duration, 160 W peak power), is spectrally sliced using a spectral pulse shaper (SPS 1), to yield two pump waves at 1550.1 nm and 1564.5 nm (spectral width ~70 GHz) and a degenerate signal/idler at 1557.7 nm (width ~130 GHz). After amplification all waves are polarisation aligned and coupled to the TM-mode of the chalcogenide waveguide. A second SPS provides filtering of excess noise and the required phase control. The output of the waveguide is measured with an optical spectrum analyser (OSA). The phase-sensitive gain is characterised by changing the relative phase of the interacting waves using SPS 2 and measuring the power of the signal relative to the unamplified signal. The approximate on-chip peak powers were 4.8 W and 2.5 W for the two pumps and 4 mW for the signal. Figures 1(b) and (c) depict output spectra and the on-chip signal gain as a function of relative phase. We can see a clear periodic dependence of the gain on the relative phase. The period of the variation is π and the ratio of maximum gain to minimum gain, i.e the main performance indicator often denoted the phase-sensitive gain, was 9.9 dB. The experimental results agree well with numerical simulations of the underlying nonlinear Schrodinger equation using a split-step Fourier method. In conclusion we have for the first time shown phase-sensitive amplification on a χ(3) photonic chip. We achieved a phase-sensitive gain of 9.9 dB which is comparable to previous demonstrations, and is sufficient to perform other processing functions such as regeneration of phase-encoded communication signals. Prospects for extending our experiment to continuous or quasicontinuous wave operation are promising and currently ongoing.

On-chip all optical error detection for ultra-low latency communications

We propose and demonstrate the first photonic-chip based all-optical error detection. The scheme could provide a favourable solution for communication systems with ultra-low latency requirements. We present results for 40 Gb/s BPSK signals.

Linear Crosstalk Compensation by All-Optical Dot-Product Operation

A new all-optical technique for compensation of linear crosstalk is demonstrated on two 40~Gb/s signals. The system realizes a dot-product between the degraded data-channels by multiple FWM processes and linear spectral processing.