This paper offers a brief introduction to silicon photonics including the basic optical waveguide, passive optical circuit performance, the addition of doped pand njunctions adjacent to the intrinsic silicon waveguide to inject a current across the waveguide, free-carrier dispersion, performance of the variable optical attenuator (VOA), and a monolithic, dual-function splitter-VOA array circuit.

In this paper, we present an analytical expression for the resonance frequency of Helmholtz attenuators with air cavity and membrane. We derive the characteristic equations based on one-dimensional isentropic acoustic models and illustrate the eeects on the resonance frequency of certain design variations. 1 INTRODUCTION The development of high speed paper machines requires a better control of ...

In this lecture will continue our quantum-mechanical treatment of linear attenuators and linear amplifiers. Among other things, we will distinguish between phaseinsensitive and phase-sensitive amplifiers. We will also show that the attenuator and the phase-insensitive amplifier preserve classicality, i.e., their outputs are classical states when their inputs are classical states. Finally, we wi...

This paper deals with the use of a magnetic levitation system as a part of a multi-stage seismic attenuator for gravitational wave interferometric antennas. The proposed configuration uses permanent magnets in attraction to balance the suspended weight, plus a closed loop position control to obtain a stable levitation. The system is analyzed using a MATLAB simulation code to compute the forces ...

Excitation in the outer loop is adjusted to obtain a minimum detected signal at the centered probe. This can be done quite accurately and defines antisymmetric excitation for the antennas (az = —aJ. Antenna #2 is then shorted at the ground plane resulting in (bl/aJ= – 1, and the phase bridge is balanced to produce a null at the detector. This balance occurs when b,= –uZ = al and establishes a p...

This beam detector accepts the narrow pulses typically encountered in electron storage rings. It is composed of a peak detector with a threshold held constant by means of an automatic gain control (AGC) loop, and of a sampler. The output is proportional to the instantaneous position of the beam center of charge and is independent of the beam current. In addition, the very small phase shift of t...

To minimize the pulse-to-pulse variation, the LCLS FEL must operate at saturation, i.e. 10 orders of magnitude brighter spectral brilliance than 3-generation light sources. At this intensity, ultra-high vacuums and windowless transport are required. Many of the experiments, however, will need to be conducted at a much lower intensity thereby requiring a reliable means to reduce the x-ray intens...