An important group of nonlinear processes in optical fibre involves the mixing of four waves due to the intensity dependence of the refractive index. It is customary to distinguish between nonlinear effects that require external/pumping waves (cross-phase modulation and parametric processes such as four-wave mixing) and self-action of the propagating optical field (self-phase modulation and mod...

PT -symmetric optics is an emerging field, with numerous applications in photonics. Here, we theoretically propose and study PT -symmetric architectures supporting novel beam-propagation controlled by appropriate manipulation of the system’s amplifying and dissipative elements. The base-platforms to observe these dynamics are binary photonic waveguide lattices consisting of dimmers, with amplif...

We examine the influence of a random flow that occurs in the convection zone on frequencies of the solar acoustic oscillations. Using a perturbative method the dispersion relation is derived in the case of a random flow that is parallel to the wave propagation. This relation is subsequently solved numerically for various parameters of the random field to find the frequencies of the random acous...

Sensorineural hearing loss, which stems primarily from the failure of mechanosensory hair cells, changes the traveling waves that transmit acoustic signals along the cochlea. However, the connection between cochlear mechanics and the amplificatory function of hair cells remains unclear. Using an optical technique that permits the targeted inactivation of prestin, a protein of outer hair cells t...

Analysis of ground-based ELF/VLF observations of injected whistler mode waves from the 1986 Siple Station experiment demonstrates the preferential magnetospheric amplification of rising over descending frequency-time ramps. From examining conjugate region receptions of ±1 kHz/s frequency-time ramps, we find that rising ramps generate an average total power 1.9 times higher than that of falling ...

The inner ear achieves a wide dynamic range of responsiveness by mechanically amplifying weak sounds. The enormous mechanical gain reported for the mammalian cochlea, which exceeds a factor of 4000, poses a challenge for theory. Here we show how such a large gain can result from an interaction between amplification by low-gain hair bundles and a pressure wave: hair bundles can amplify both thei...

The benefit of finding particular exact and asymptotic solutions of non-integrable non-linear partial differential equations is considered. It is shown how explicit analytical solutions predict important features of the waves behavior even outside their formal applicability. In particular, an arbitrary initial pulse splits in a numerical solution into the train of localized waves each described...

We report an experimental study on the effect of an external phase noise on the parametric amplification of surface waves. We observe that both the instability growth rate and the wave amplitude above the instability onset are decreased in the presence of noise. We show that all the results can be understood with a deterministic amplitude equation for the wave in which the effect of noise is ju...

High speed, high efficiency, low noise and high saturation power are the characteristics desired for detectors in high bit-rate long-haul optical communication systems. We present the modeling of Traveling-wave Amplification Photodetectors (TAP detectors). These novel monolithic devices combine optical gain and absorption in a distributed fashion along a traveling-wave structure, providing high...

SIDA XING, DAVIDE GRASSANI, SVYATOSLAV KHARITONOV, LAURENT BRILLAND, CÉLINE CAILLAUD, JOHANN TROLÈS, AND CAMILLE-SOPHIE BRÈS* Ecole Polytechnique Fédérale de Lausanne, Photonic Systems Laboratory (PHOSL), STI-IEL, Station 11, CH-1015 Lausanne, Switzerland SelenOptics, 57 rue de La Girolle, 35170 Bruz, France Equipe Verres et Céramiques, UMR-CNRS 6226, Institut des Sciences Chimiques de Rennes, ...