The nature of the cosmological background of gravitational waves is a subject of great interest at present, with many possible sources ranging from quantum fluctuations in a string-dominated phase 1,2 or inflation , to oscillations of cosmic string loops . Here we focus instead on a powerful mechanism for distortion and amplification of any existing gravitational wave background namely damped p...

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 modeling and initial experimental results on Traveling-wave Amplification Photodetectors (TAP detectors). These novel monolithic devices combine optical gain and absorption in a traveling-wave structure, providing hig...

Time-reversal symmetry for elastic wave propagation breaks down in a resonant mass-in-mass lattice whose inner-stiffness is weakly modulated in space and in time in a wave-like fashion. Specifically, one-way wave transmission, conversion and amplification as well as unidirectional wave blocking are demonstrated analytically through an asymptotic analysis based on coupled mode theory and numeric...

To study human cone phototransduction, the alpha-wave of the ERG was recorded from color normals, dichromats, and patients with retinitis pigmentosa. A model of the activation phase of phototransduction, previously fitted to responses from single rods and the rod alpha-wave, was modified and fitted to the human cone alpha-wave. The modified model fits the cone alpha-wave well and allows questio...

Many applications in photonics require all-optical manipulation of plasma waves1, which can concentrate electromagnetic energy on sub-wavelength length scales. This is difficult in metallic plasmas because of their small optical nonlinearities. Some layered superconductors support Josephson plasma waves (JPWs)2,3, involving oscillatory tunneling of the superfluid between capacitively coupled pl...

Singular vector (SV) analysis has proved to be helpful in understanding the linear instability properties of various types of flows. SVs are the perturbations with the largest amplification rate over a given time interval when linearizing the equations of a model along a particular solution. However, the linear approximation necessary to derive SVs has strong limitations and does not take into ...