11,180 research outputs found
Phase Noise Power Spectral Density Measurement of Narrow Linewidth CW Lasers Using an Optical Phase-Locked Loop
Optical Phase Locking techniques: an overview and a novel method based on Single Side Sub-Carrier modulation
A short overview on Optical Phase locking techniques and a detailed description of the Phase Locking technique based on Sub-Carriers modulation is presented. Furthermore, a novel Single Side Sub-Carrierbased Optical Phase Locked Loop (SS-SC-OPLL), with off the shelf optical components, is also presented and experimentally demonstrated. Our new method, based on continuous wave semiconductor lasers and optical single side sub-carrier modulation using QPSK LiNbO3 modulator, allows a practical implementation with better performance with respect to the previously proposed OPLL circuits, and permits an easy use in real time WDM signal coherent demodulation
Design, analysis and experimental testing of BPSK homodyne receivers based on subcarrier optical phase-locked loop
2.5-Gb/s BPSK Ultradense WDM Homodyne Coherent Detection Using a Subcarrier-Based Optical Phase-Locked Loop
Homodyne coherent detection of ASK and PSK signals performed by a subcarrier optical phase-locked loop
Optical transmission systems based on homodyne coherent detection of 2-ASK and pilot carrier 2-PSK signals have been implemented. ASK data has been transmitted at 2.5 Gbps, while 2.5 Gbps and 10 Gbps PSK systems have been tested. The proposed architecture is based on a new optical phase locked loop founded on sub-carrier modulation and leads to new compact integrated receivers and new transmission formats, thus opening new opportunities for future optical systems
Dynamically Tunable Lasers Phase NoiseCharacterization and their Use in a 10 Gbps Optical Coherent Transmission System
Analysis of a dry friction problem under small displacements: application to a bolted joint
This study presents an analysis of the problem of macroscopic contact of steel upon steel with dry friction, in the specific case of a bolted joint. The configurations of these types of joints result in very small displacements and interface sliding velocities. To understand how the system formed by the two surfaces in contact works, an experiment was carried out. The analysis of the results obtained made it possible to define the behavior of the system and to model the variations of the main parameters by original and continuous laws. These laws accurately correlate to all the results of the tests effectuated
Uniqueness of the thermodynamic limit for driven disordered elastic interfaces
We study the finite size fluctuations at the depinning transition for a
one-dimensional elastic interface of size displacing in a disordered medium
of transverse size with periodic boundary conditions, where
is the depinning roughness exponent and is a finite aspect ratio
parameter. We focus on the crossover from the infinitely narrow () to
the infinitely wide () medium. We find that at the thermodynamic
limit both the value of the critical force and the precise behavior of the
velocity-force characteristics are {\it unique} and -independent. We also
show that the finite size fluctuations of the critical force (bias and
variance) as well as the global width of the interface cross over from a
power-law to a logarithm as a function of . Our results are relevant for
understanding anisotropic size-effects in force-driven and velocity-driven
interfaces.Comment: 10 pages, 12 figure
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