Generation of coherent supercontinuum in a-Si :H waveguides : experiment and modeling based on measured dispersion profile

Hydrogenated amorphous silicon (a:Si-H) has recently been recognized as a highly nonlinear CMOS compatible photonic platform. We experimentally demonstrate the generation of a supercontinuum (SC) spanning over 500 nm in a-Si:H photonic wire waveguide at telecommunication wavelengths using femtosecond input pulse with energy lower than 5 pJ. Numerical modeling of pulse propagation in the waveguide, based on the experimentally characterized dispersion profile, shows that the supercontinuum is the result of soliton fission and dispersive wave generation. It is demonstrated that the SC is highly coherent and that the waveguides do not suffer from material degradation under femtosecond pulse illumination. Finally, a direct comparison of SC generation in c-Si and a-Si:H waveguides confirms the higher performances of a-Si:H over c-Si for broadband low power SC generation at telecommunication wavelengths.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Nonlinear optical interactions in silicon waveguides

The strong nonlinear response of silicon photonic nanowire waveguides allows for the integration of nonlinear optical functions on a chip. However, the detrimental nonlinear optical absorption in silicon at telecom wavelengths limits the efficiency of many such experiments. In this review, several approaches are proposed and demonstrated to overcome this fundamental issue. By using the proposed methods, we demonstrate amongst others supercontinuum generation, frequency comb generation, a parametric optical amplifier, and a parametric optical oscillator

Supercontinuum generation in hydrogenated amorphous silicon waveguides at telecommunication wavelengths

We report supercontinuum (SC) generation centered on the telecommunication C-band (1550 nm) in CMOS compatible hydrogenated amorphous silicon waveguides. A broadening of more than 550 nm is obtained in 1cm long waveguides of different widths using as pump picosecond pulses with on chip peak power as low as 4 W. © 2014 Optical Society of America.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Supercontinuum generation in hydrogenated amorphous silicon waveguides in the femtosecond regime

Supercontinuum generation in CMOS compatible hydrogenated amorphous silicon waveguides with femtosecond pulses at telecommunication wavelengths is experimentally studied. It is shown that stable 540 nm broad supercontinua can be obtained in 1 cm-long waveguides. © 2014 Optical Society of America.info:eu-repo/semantics/publishe

Beam self-trapping in pyroelectric photorefractive crystals

International audienceWhile most photorefractive (PR) beam self-trapping configurations require application of a high external voltage. we instead propose to use PR pyroelectric medium to efficiently trap beams by simple temperature control. This new concept is based on uniform temperature change of a pyroelectric PR crystal which creates an internal electric field that is screened under a local illumination by nonlinear photorefractive effec

Pyroliton : Pyroelectric spatial solitons

International audienceThe concept of optical beam self-trapping in pyroelectric photorefractive medium is presented. We show that the temperature controlled spontaneous polarisation of ferroelectric crystals produces an optical nonlinearity that can lead to formation of 2-D spatial soliton named pyroliton. Experimental demonstrations performed in lithium niobate crystals illustrate that efficient self-trapping occurs either for ordinary or extraordinary polarisation under moderate temperature increase. For instance, a 15μm diameter pyroliton can be formed with a 10 degree temperature raise

Three dimensional time dependent model with two photoactive centres for photorefractive spatial solitons in LiNbO3

We present a new 3D time dependent model for photorefractive beam self focusing in undoped biased LiNbO 3 where iron impurities and Nb Li polarons are considered as two photoactive centres. Focusing or defocusing regimes are exhibited with respect to beam intensity and bias voltage in good agreement with experiments

Surface-wave pyroelectric photorefractive solitons

International audienceSurface-wave solitons, induced by the pyroelectric effect, are formed at the interface between a photorefractive ferroelectric medium and a linear medium. These optical solitons are trapped in both transverse dimensions and are efficiently attracted to the interface. The asymmetric shape of the nonlinear index change formed under the charge saturation regime is responsible for the surface-wave solitons' formation. Experimental demonstrations are performed in a lithium niobate sample with moderate temperature change. The phenomenon is successfully explained through numerical simulations

Beam self-trapping by pyroelectric effect

International audienc