We demonstrate an ultra-low light level optical modulator using a tapered nano fiber embedded in a hot rubidium vapor. The control and signal beams are co-propagating but orthogonally polarized, leading to a degenerate V-system involving coherent superpositions of Zeeman sublevels. The modulation is due primarily to the quantum Zeno effect for the signal beam induced by the control beam. For a ...

The Spallation Neutron Source (SNS) accumulator ring is designed to accumulate, via H− injection, protons of 2 MW beam power at 1 GeV kinetic energy at a repetition rate of 60 Hz [1]. At such beam intensity, electroncloud is expected to be one of the intensity-limiting mechanisms that complicate ring operations. This paper summarizes mitigation strategy adopted in the design, both in suppressin...

Rats use their whiskers as tactile sensors to sense their environment. Active whisking, moving whiskers back and forth continuously, is one of prominent features observed in rodents. They can discriminate different textures or extract features of a nearby object such as size, shape and distance through active whisking. There have been studies to localize objects with artificial whiskers inspire...

Guiding the growth of a neurite by directing ~800 nm laser light to the leading edge of the neurite's growing region can be accomplished by controlling the position and direction in three dimensional space of a tapered optical fiber through which the light is projected. We control the position, angle and power of the laser beam to direct the growth of actin accumulations in neurites which affec...

Planar directional coupler using Substrate Integrated Waveguide technology (SIW) is proposed in this paper. The SIW coupler with tapered microstrip-SIW transitions are integrated on the same substrate. Planar form makes this coupler structure easily integrable in microwave planar circuits. These proposed power dividers can be applied to the design of the beam-forming network for communication s...

A new beam propagation method (BPM) is developed based on a direct approximation to the propagator by its [(p-1)/p] Padé approximant. The approximant is simple to construct and has the desired damping effect for the evanescent modes. The method is applied to a tapered waveguide for TM-polarized waves, based on the energy-conserving improvement of the one-way Helmholtz equation. Numerical result...

We report on the phase-locking of two diode lasers based on self-seeded tapered amplifiers. In these lasers, a reduction of linewidth is achieved using narrow-band high-transmission interference filters for frequency selection. The lasers combine a compact design with a Lorentzian linewidth below 200 kHz at an output power of 300 mW for a wavelength of 780 nm. We characterize the phase noise of...

A new beam propagation method (BPM) is developed based on a direct approximation to the propagator using the [p/(p+1)] Padé approximant. It is simple to construct and has the desired damping effect for the evanescent modes. The method is applied to a tapered waveguide for TM polarized waves, using the oneway Helmholtz equation and its energy conserving improvement. Numerical results are compare...

Tapered Yb-doped fiber (T-YDF) can balance the suppression of transverse mode instability (TMI) and stimulated Raman scattering (SRS) in high power lasers. In this work, we have constructed an all-fiberized master oscillator amplifier emitting at central wavelength 1050 nm based on a T-YDF investigated laser performance respective co-pumped counter-pumped configurations. The results show that e...