A microrod-resonator Brillouin laser with 240 Hz absolute linewidth

We demonstrate an ultralow-noise microrod-resonator based laser that oscillates on the gain supplied by the stimulated Brillouin scattering optical nonlinearity. Microresonator Brillouin lasers are known to offer an outstanding frequency noise floor, which is limited by fundamental thermal fluctuations. Here, we show experimental evidence that thermal effects also dominate the close-to-carrier frequency fluctuations. The 6-mm diameter microrod resonator used in our experiments has a large optical mode area of ~100 {\mu}m$^2$, and hence its 10 ms thermal time constant filters the close-to-carrier optical frequency noise. The result is an absolute laser linewidth of 240 Hz with a corresponding white-frequency noise floor of 0.1 Hz$^2$/Hz. We explain the steady-state performance of this laser by measurements of its operation state and of its mode detuning and lineshape. Our results highlight a mechanism for noise that is common to many microresonator devices due to the inherent coupling between intracavity power and mode frequency. We demonstrate the ability to reduce this noise through a feedback loop that stabilizes the intracavity power.Comment: 11 pages, 5 figure

Phase Coherent Link of an Atomic Clock to a Self-Referenced Microresonator Frequency Comb

The counting and control of optical cycles of light has become common with modelocked laser frequency combs. But even with advances in laser technology, modelocked laser combs remain bulk-component devices that are hand-assembled. In contrast, a frequency comb based on the Kerr-nonlinearity in a dielectric microresonator will enable frequency comb functionality in a micro-fabricated and chip-integrated package suitable for use in a wide-range of environments. Such an advance will significantly impact fields ranging from spectroscopy and trace gas sensing, to astronomy, communications, atomic time keeping and photonic data processing. Yet in spite of the remarkable progress shown over the past years, microresonator frequency combs ("microcombs") have still been without the key function of direct f-2f self-referencing and phase-coherent frequency control that will be critical for enabling their full potential. Here we realize these missing elements using a low-noise 16.4 GHz silicon chip microcomb that is coherently broadened from its initial 1550 nm wavelength and subsequently f-2f self-referenced and phase-stabilized to an atomic clock. With this advance, we not only realize the highest repetition rate octave-span frequency comb ever achieved, but we highlight the low-noise microcomb properties that support highest atomic clock limited frequency stability

Third-harmonic generation in optical microfibers: From silica experiments to highly nonlinear glass prospects

International audienceUsing optical microfibers, phase matching between different propagation modes allows for third-harmonic generation (THG). After detailing the relevant phase matching conditions and overlap integrals, we provide a comparison between THG effective efficiencies in silica and tellurite glasses. We also explain the relatively easy, wideband, conversion that we observe experimentally in silica glass microfibers, from 155 mu m to the green, by the geometry of the tapering region

Dynamical Systems of Oscillating Ultrashort Pulse Pairs

We propose a theoretical method to model the complex phenomenon of oscillating ultrashort pulse pair molecules. Using a phenomenological viewpoint, we construct effective dynamical systems, whose degrees of freedom are the inter-pulse timing and overall phase. The effective dynamical system is characterized by a limit cycle attractor that is fit to the experimentally measured soliton oscillation using data-driven methods. Good agreement is achieved between the dynamical system orbits and experimental observations made in a mode-locked fiber laser

Nonlinear plasmonic metasurfaces assisted laser mode locking

Plasmonic metasurfaces are artificial 2D layers made of subwavelength elementary cells, which give rise to novel wave properties that do not exist in nature. In the linear regime, their applications have been extensively studied, especially in wavefront manipulation for lensing, holography or polarization control. Interests in metasurfaces operating in nonlinear regime have also increased due to their ability to efficiently convert the fundamental light into harmonic frequencies and multiphoton emissions. Nevertheless, practical applications in the nonlinear regime have been rarely reported. In this study, we report that plasmonic metasurfaces with well-controlled polarimetric nonlinear transfer functions perform as saturable absorbers with modulation performances superior to that of other 2D materials. We employ planar nanotechnologies to fabricate 2D plasmonic metasurfaces with precise size, gap and orientation. We quantify the relationship between saturable absorption and the plasmonic resonances of the unit cell by altering the excitation power of pumping laser, the polarization of incident light and the geometrical parameters of the plasmonic metasurfaces. Finally, we provide a practical implementation by integrating the saturable metasurfaces into a fiber laser cavity and realize a stable self-starting ultrashort laser pulse generation. As such, this work sheds light on ultrathin nonlinear saturable absorbers for applications where nonlinear functions are required, such as in ultrafast laser or neuromorphic circuits

Nonlinear plasmonic metasurfaces assisted laser mode locking

Plasmonic metasurfaces are artificial 2D layers made of subwavelength elementary cells, which give rise to novel wave properties that do not exist in nature. In the linear regime, their applications have been extensively studied, especially in wavefront manipulation for lensing, holography or polarization control. Interests in metasurfaces operating in nonlinear regime have also increased due to their ability to efficiently convert the fundamental light into harmonic frequencies and multiphoton emissions. Nevertheless, practical applications in the nonlinear regime have been rarely reported. In this study, we report that plasmonic metasurfaces with well-controlled polarimetric nonlinear transfer functions perform as saturable absorbers with modulation performances superior to that of other 2D materials. We employ planar nanotechnologies to fabricate 2D plasmonic metasurfaces with precise size, gap and orientation. We quantify the relationship between saturable absorption and the plasmonic resonances of the unit cell by altering the excitation power of pumping laser, the polarization of incident light and the geometrical parameters of the plasmonic metasurfaces. Finally, we provide a practical implementation by integrating the saturable metasurfaces into a fiber laser cavity and realize a stable self-starting ultrashort laser pulse generation. As such, this work sheds light on ultrathin nonlinear saturable absorbers for applications where nonlinear functions are required, such as in ultrafast laser or neuromorphic circuits

Extreme wave dynamics from incoherent dissipative solitons in fiber laser cavities

22 pags., 15 figs.We introduce several important features of the dynamics of chaotic pulse packets that are ubiquitous in ultrafast fiber lasers experiments, and propose to encompass these dynamics into the denomination of incoherent dissipative solitons. Based on numerical simulations, and illustrated by fiber laser experiments, we show that incoherent dissipative solitons can take the form of chaotic soliton bunches and noise-like pulses. Such instabilities are found to exist in the anomalous regime of cavity dispersion. In some range of parameters, these formations lead to the observation of optical rogue wave phenomena and other extreme wave transients.This work was supported by the Indo-French Center for the Promotion of Advanced Research (CEFIPRA/IFCPAR, project 5104-2); the Centre National de la Recherche Scientifique (CNRS); the Agence Nationale de la Recherche through projects SOLICRISTAL (ANR-2010-BLANC-0417-01), OPTIROC (ANR-12- BS04-0011), and LabEx ACTION (ANR-11-LABX-01-01); the Région Bourgogne; and the Fonds Européen de Développement Régional (FEDER). Ph.G. acknowledges the important contribution of C Lecaplain in the early experimental explorations of dissipative rogue waves. The work of JMSC is supported by the Volkswagen Stiftung, the MINECO under contract TEC2015- 71127-C2-1-R, and by C.A.M. under contract S2013/MIT-2790Peer Reviewe

Saturable plasmonic metasurfaces for laser mode locking

International audienceMetamaterials are artificial materials made of subwavelength elementary cells that give rise to unexpected wave properties that do not exist naturally. However, these properties are generally achieved due to 3D patterning, which is hardly feasible at short wavelengths in the visible and near-infrared regions targeted by most photonic applications. To overcome this limitation, metasurfaces, which are the 2D counterparts of metamaterials, have emerged as promising platforms that are compatible with planar nanotechnologies and thus mass production, which platforms the properties of a metamaterial into a 2D sheet. In the linear regime, wavefront manipulation for lensing, holography, and polarization control has been achieved recently. Interest in metasurfaces operating in the nonlinear regime has also increased due to the ability of metasurfaces to efficiently convert incident light into harmonic frequencies with unusual polarization properties. However, to date, the nonlinear absorption of metasurfaces has been mostly ignored. Here, we demonstrate that plasmonic metasurfaces behave as saturable absorbers with modulation performances superior to the modulation performance of other 2D materials and exhibit unusual polarimetric nonlinear transfer functions. We quantify the link between saturable absorption, the plasmonic resonances of the unit cell and their distribution in a 2D metasurface, and finally provide a practical implementation by integrating the metasurfaces into a fiber laser cavity operating in pulsed regimes driven by the metasurface properties. As such, this work provides new perspectives on ultrathin nonlinear saturable absorbers for applications where tunable nonlinear transfer functions are needed, such as in ultrafast lasers or neuromorphic circuits

Silicon-microring into a fiber laser cavity for high-repetition-rate pulse train generation

International audienceIn 1997, Yoshida et al. inserted a Fabry-Perot filter in a modulation instability fiber laser cavity [1], the free spectral range (FSR) of the Fabry-Perot fixed the RF to 115 GHz; however the pulsed laser was poorly stable. Since then, lasers of increasing performance have been demonstrated using variants of this method. In 2012, Peccianti et al., demonstrated the first fiber laser harmonically mode-locked by integrated high-finesse microresonator [2]. The doped silica, on-chip microresonator provided both high spectral selectivity and nonlinearity, thus promoting the dynamics pulsed at 200 GHz. By using a silicon microring resonator (SMRR), this approach lead to the recent realization of 110 GHz-RF mode-locked fiber laser [3]. Working with silicon takes advantage of the huge investment and experience from the microelectronics industry, and contributes to the development of a monolithic platform for optoelectronics [4]. The high Kerr nonlinearity of silicon is instrumental to induce mode locking with low pumping threshold. However, at the main telecom wavelength (1.55 µm), two photo absorption, free-carriers dispersion and their thermalization have to be considered [5], and can be detrimental to formation of the ultrafast dynamics