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We report the observation of Brillouin backscattering in a 50-cm long spiral high-index doped silica chip waveguide and measured a Brillouin frequency shift of 16 GHz which is in very good agreement with theoretical predictions and numerical simulations based on the elastodynamics equation., Comment: 5 pages, 6 figures

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We demonstrate a new metal-wire waveguide topology, namely a four-wire waveguide, which simultaneously acts as a broadband terahertz polarization-division multiplexer and as a novel platform to realize the independent manipulation of polarization-division multiplexed terahertz signals.

Starting from 175-fs-long pulses at 1035 nm, we directly generate 20 μJ, 4.6 fs visible pulses through the nonlinear mixing between the spatial modes of a 3-m-long Ar-filled hollow-core fiber, without any pulse post-compression.

Photonic integrated circuits (PICs) are a key component [1] for future telecommunication networks, where demands for greater bandwidth, network flexibility, low energy consumption and cost must all be met. The quest for all optical components has naturally targeted materials with extremely large nonlinearity, including chalcogenide glasses (ChG) [2] and semiconductors, such as silicon [3] and AlGaAs [4]. Yet issues such as immature fabrication technologies for ChG, and high linear and nonlinear losses for semiconductors, motivate the search for other materials. Here we present the first demonstration of nonlinear optics in integrated silica based glass waveguides using continuous wave (CW) light. We demonstrate four wave mixing (FWM), with low (7mW) CW pump power at a wavelength of 1550nm, in high index doped silica glass ring resonators capable of performing in photonic telecommunications networks as linear filters [5]. The high reliability, design flexibility, and manufacturability of our device raises the possibility of a new platform for future low cost nonlinear all optical PICs., Comment: 15 pages, 5 figures, 32 references

We report optical neuromorphic processors based on Kerr micro-combs that are programmable, scalable and ultra-high speed. We demonstrate a perceptron at 11.9Giga-OPS at 8 bits, or 95.2 Gbps, and a convolutional accelerator at 11TeraOPs/s.

We experimentally demonstrate enhanced four-wave mixing in micro-ring resonators (MRRs) integrated with graphene oxide films. We achieve up to ~7.6-dB enhancement in conversion efficiency for a uniformly coated MRR and ~10.3-dB for a patterned device.

We demonstrate a photonic radio frequency (RF) transversal filter based on an integrated optical micro-comb source featuring a record low free spectral range of 49 GHz yielding 80 micro-comb lines across the C-band. This record-high number of taps, or wavelengths for the transversal filter results in significantly increased performance including a QRF factor more than four times higher than previous results. Further, by employing both positive and negative taps, an improved out-of-band rejection of up to 48.9 dB is demonstrated using Gaussian apodization, together with a tunable centre frequency covering the RF spectra range, with a widely tunable 3-dB bandwidth and versatile dynamically adjustable filter shapes. Our experimental results match well with theory, showing that our transversal filter is a competitive solution to implement advanced adaptive RF filters with broad operational bandwidths, high frequency selectivity, high reconfigurability, and potentially reduced cost and footprint. This approach is promising for applications in modern radar and communications systems., Comment: 19 pages, 12 figures, 107 references, Winner IEEE JLT 2019 Paper of the Year Revised - references updated and links to award websites added

We demonstrate efficient, low power, continuous-wave four-wave mixing in the C-band, using a high index doped silica glass micro ring resonator having a Q-factor of 1.2 million. A record high conversion efficiency for this kind of device is achieved over a bandwidth of 20nm. We show theoretically that the characteristic low dispersion enables phase-matching over a bandwidth > 160nm., 7 pages, 5 figures, 24 references

International audience; Modulation instability is a fundamental process of nonlinear physics, leading to the unstable breakup of a constant amplitude solution of a particular physical system. There has been particular interest in studying modulation instability in the cubic nonlinear Schrödinger equation (NLSE) which models a wide range of nonlinear systems including superfluids, fiber optics, plasmas and Bose-Einstein condensates. Modulation instability in the NLSE is also a significant current area of study in the context of understanding the emergence of high amplitude or high intensity events that satisfy "rogue wave" statistical criteria. Here, exploiting recent advances in real time ultrafast optical metrology via an optical time lens system, we perform real-time measurements in an NLSE optical fibre system of the unstable breakup of a continuous wave field, simultaneously characterising emergent modulation instability breathers, and their associated statistics. Our results allow quantitative comparison between experiment, modelling, and theory, and we show very good agreement in both extracted intensity profiles and associated statistics.

The goal of this report is to study the conditions for efficient THz generation using Frequency Difference Generation principle. In particular, two CW IR beams are used together with a periodically poled lithium niobate crystal in order to generate a continuous THz wave. As a source of the IR pump beams we consider a 30W (CW) IPG Er-doped fiber-amplifier which currently is the most powerful commercial amplifier on the market. The work is motivated by application of CW sources of THz waves in high bit wireless communication applications. The amplifier will allow to mix two optically modulated IR beams and to generate modulated THz signal.

We demonstrate sub-picosecond wavelength conversion in the C-band via four wave mixing in a 45cm long high index doped silica spiral waveguide. We achieve an on/off conversion efficiency (signal to idler) of +16.5dB as well as a parametric gain of +15dB for a peak pump power of 38W over a wavelength range of 100nm. Furthermore, we demonstrated a minimum gain of +5dB over a wavelength range as large as 200nm., Comment: 8 pages, 4 figures, 30 references

We present an analytical model describing the full electromagnetic propagation in a THz Time Domain Spectroscopy (THz-TDS) laser based system. We pay particular attention to the modelling of the time-frequency behavior of all the stages, which compose our experimental set-up. In particular, our model takes into account the following features: pump beam focusing into the generation crystal; phase-matching between pump and THz pulses inside both the generation and detection crystals; chromatic dispersion and absorption inside the materials; Fabry-Perot effect in both the crystals; diffraction along the propagation, focalization and overlapping between THz and probe beams; Electro-Optic Sampling. The data obtained from our experimental set-up are in optimum agreement with simulations, so proving the effectiveness of our model.

International audience; We report on the generation of Riemann waves in nonlinear optical Fiber. These propagation dynamics, associated with the shoaling of appropriately pre-chirped optical pulses, are investigated both numerically and experimentally.

An analytical model describing a laser based set-up for wideband THz generation and detection is presented. Particular attention is focused on the main broadband phenomena, which occur when THz radiations have to be handled.

No abstract available.

Nonlinear photonic chips have succeeded in generating and processing signals all-optically with performance far superior to that possible electronically - particularly with respect to speed. Although silicon-on-insulator has been the leading platform for nonlinear optics, its high two-photon absorption at telecommunications wavelengths poses a fundamental limitation. This paper reviews some of the recent achievements in CMOS-compatible platforms for nonlinear optics, focusing on amorphous silicon and Hydex glass, highlighting their potential future impact as well as the challenges to achieving practical solutions for many key applications. These material systems have opened up many new capabilities such as on-chip optical frequency comb generation and ultrafast optical pulse generation and measurement., 8 pages, 10 figures 80 references. arXiv admin note: substantial text overlap with arXiv:1404.5610

We introduce a simple approach for characterizing the ferroelectric domain distribution in bulk quadratic crystals. The approach is demonstrated in a lithium tantalate sample with periodic electric field poling and random mark-to-space ratio.

We experimentally observed and explained bulk Second Harmonic Generation via Random Quasi-Phase-Matching, derived from a periodically poled Lithium Tantalate sample with a randomly patterned mark-to-space-ratio.

We demonstrate a range of novel functions based on a high index doped silica glass CMOS compatible platform. This platform has promise for telecommunications and on-chip WDM optical interconnects for computing., Comment: 6 pages, 7 figures, 67 references, 1 table. arXiv admin note: text overlap with arXiv:1404.5361

Ultrashort pulsed lasers, operating through the phenomenon of mode-locking, have played a significant role in many facets of our society for 50 years, for example in the way we exchange information, measure and diagnose diseases, process materials and in many other applications. The ability to phase-lock the modes of the high-quality resonators recently exploited to demonstrate optical combs, would allow mode-locked lasers to benefit from their high optical spectral quality in order to realize novel sources such as precision optical clocks for applications to metrology, telecommunications, microchip-computing, and many other areas. We demonstrate the first mode-locked laser based on a micro-cavity resonator. It operates via a new mode-locking method we termed Filter-Driven (FD) Four-Wave-Mixing, and is based on a CMOS-compatible high quality factor micro-ring resonator. It achieves stable self-starting oscillation with negligible amplitude noise at ultrahigh repetition rates, and spectral linewidths well below 130 kHz., Comment: 16 pages, 32 references, 5 figures

The anisotropic effective mass of electrons is directly measured using time-resolved THz- pump/THz-probe techniques in a n-doped InGaAs semiconductor thin film. A microscopic theory is used to attribute this anisotropy in the THz probe transmission to the nonparabolicity of the conduction band. Self-consistent light-matter coupling is shown to contribute significantly to the THz response.

Frontiers in Optics 2006/Laser Science XXII conference, OSA Optical Society of America Annual Meeting, 12 October 2006, Rochester

We have investigated the power threshold of discrete Kerr surface solitons at the interface between discrete and continuous 1D AlGaAs medium. Distinct thresholds were measured for interface solitons localized at different sites from the interface.

Physical Review Letters

International audience