Experiments are reported on inverse free-electron-laser acceleration, including for the first time observations of the energy change as a function of relative injection phase of the electron bunches. The microwave accelerating structure consists of a uniform circular waveguide with a helical wiggler and an axial magnetic field. Acceleration of the entire beam by 6% is seen for 6 MeV electron bu...

Axial dynamic tension of a flexible helical fiber is found to lead to a specific, extraordinary nonlinear wave consisting of two different portions. The leading portion is a quasiperiodical propagating wave with rotation opposite to the initial twist of the helix, while the rear portion is a sequence of standing waves rotating in the reverse direction. The interface is the origin of two angular...

We report the design of a mirror correcting system used at the Large Helical Device (LHD) to convert the output radiation of the CPI 84 GHz gyrotron into the HE11 mode of a corrugated waveguide transmission line. The radiation pattern of the gyrotron is measured using an IR camera at LHD. The measured data is analyzed at MIT to retrieve the phase distribution of the radiation. The moments of th...

Silk fibers are expected to become a pathway to biocompatible and bioresorbable waveguides, which could be used to deliver localized optical power for various applications, e.g., optical therapy or imaging inside living tissue. Here, for the first time, the linear and nonlinear optical properties of natural silk fibers have been studied. The waveguiding properties of silk fibroin of largely unp...

Chiral surface plasmon polaritons (SPPs) can be generated by linearly polarized light incident at the end of a nanowire, exciting a coherent superposition of three specific nanowire waveguide modes. Images of chiral SPPs on individual nanowires obtained from quantum dot fluorescence excited by the SPP evanescent field reveal the chirality predicted in our theoretical model. The handedness and s...

We show how quantized transport can be realized in Floquet chains through encapsulation of a chiral or helical shift. The resulting is immutable rather than topological the sense that it neither requires band gap nor affected by arbitrarily strong perturbations. Transport still characterized quantities but shift prevents phase transitions. To explore we introduce concept shiftbox, explain relev...

in order to implement an integrated optical quantum circuit, designing waveguides based on the quantum box is of prime importance. to do this we have investigated optical waveguide both with and without optical pumping. the rate of absorption and emission using an array of algaas/gaas quantum box core/shell structure in the optical waveguide with various pumping intensities has computed. by con...

This paper reports on an investigation into the propagation of guided modes in curved waveguides and their scattering by inhomogeneities. In a general framework, the existence of propagation modes traveling in curved waveguides is discussed. The concept of translational invariance, intuitively used for the analysis of straight waveguides, is highlighted for curvilinear coordinate systems. Provi...