Search results for "Amplifier"
showing 10 items of 239 documents
Generation of parabolic pulses and applications for optical telecommunications
2009
International audience; Parabolic pulses in optical fibers have stimulated an increasing number of applications. We review here the physics underlying the generation of such self-similar pulses as well as the results obtained in a wide-range of passive or active experimental configurations.
Pulse transition to similaritons in normally dispersive fibre amplifiers
2013
selected by the editors of Journal of Optics as a Highlight of 2013a video linked to the experiments can be seen at : http://youtu.be/thbXaW91D5g; International audience; A detailed experimental characterization of the transition process of an initially Gaussian pulse to the asymptotic self-similar parabolic solution in optical fibre amplifiers operating in the normal dispersion regime is performed.
Universal soliton pattern formations in passively mode-locked fiber lasers
2011
International audience; We investigate multiple-soliton pattern formations in a figure-of-eight passively mode-locked fiber laser. Operation in the anomalous dispersion regime with a double-clad fiber amplifier allows generation of up to several hundreds of solitons per round trip. We report the observation of remarkable soliton distributions: soliton gas, soliton liquid, soliton polycrystal, and soliton crystal, thus indicating the universality of such complexes.
CMOS Capacitance-to-Time Converter-Based Interface for Differential Capacitive Sensors
2020
This paper presents pre-layout simulation results on a CMOS implementation of a capacitance-to-time converter-based electronic interface for differential capacitive sensors. Its simple architecture, comprising only three operational amplifiers (OA) and a digital mixer (inverted XOR gate) allows, by properly setting the values of seven biasing resistors, to fit the working range anywhere from few fF to hundreds of pF, giving the output quasi-digital signals (T and PW) in the useful μs-ms range (appropriate for direct interfacing with general purposes microcontrollers). A couple of illustrative examples are provided.
Pico: A data acquisition program for picosecond laser spectroscopy
1992
Abstract A data acquisition and control program for picosecond pump and probe experiments has been developed. The program PICO is written in C-programming language for maximum efficiency. The software which runs on an IBM PC compatible microcomputer controls a stepper motor driven optical delay, and at the same time collects data from a digital lock-in amplifier. PICO can be used to control any experiment utilizing two-beam pump probe technique. The modular structure of the software allows for easy implementation with different hardware configurations. The program includes: measurement option, manual control of the delay line using a joystick and functions for file retrieval and editing. Ad…
Novel constant current driver for ISFET/MEMFETs characterization
2001
Abstract In the present work a new constant current driver for ISFETs and MEMFETs sensors has been developed. The proposed circuit maintains the ISFET/MEMFET operation point at constant drain–source current and voltage. The combination of some programmable current sources and an appropriate selection of a simple precision resistor allow a good ISFET/MEMFET polarization. The use of operational amplifiers with low offset and drift are required to provide the buffering function needed by the sensor.
A Tunable, Fullerene‐Based Molecular Amplifier for Vibrational Circular Dichroism
2019
Abstract Vibrational circular dichroism (VCD) studies are reported on a chiral compound in which a fullerene C60 moiety is used as an electron acceptor and local VCD amplifier for an alanine‐based peptide chain. Four redox states are investigated in this study, of which three are reduced species that possess low‐lying electronic states as confirmed by UV/Vis spectroelectrochemistry. VCD measurements in combination with (TD)DFT calculations are used to investigate (i) how the low‐lying electronic states of the reduced species modulate the amplification of VCD signals, (ii) how this amplification depends on the distance between oscillator and amplifier, and (iii) how the spatial extent of the…
Cladding-Pumped Er/Yb-Co-Doped Fiber Amplifier for Multi-Channel Operation
2022
The Institute of Solid State Physics, University of Latvia, as a Center of Excellence, has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART2. We express our gratitude to rer. nat. Nicoletta Haarlammert from Fraunhofer Institute for Applied Optics and Precision Engineering IOF for the refractive index measurements of ytterbium/erbium-co-doped fibers. This work is supported by the European Regional Development Fund project No. 1.1.1.1/18/A/068.
Performance analysis of dual-pump nonlinear amplifying loop mirror mode-locked all-fibre laser
2019
We numerically characterise, in the three-dimensional space of adjustable cavity parameters, the performance of a recently reported layout of a flexible figure-8 laser having two independently pumped segments of active fibre in its bidirectional ring (Smirnov et al 2017 Opt. Lett. 42 1732–5). We show that this optimisation problem can be efficiently addressed by applying a regression model based on a neural-network algorithm.
Synthetic approach to the design of wide-band microwave injection-locked amplifiers
2010
In this work, a synthesis-based approach to the realization of wide-band microwave injection-locked amplifiers (ILA) is proposed. To this purpose, a transmission-type topology is combined with a feedback structure in which the "core ILA" is intentionally separated from the output (power) amplifier. A modular, matched, design of individual building blocks of the core ILA is then adopted, which allows their first-approximation exact modeling in the dynamical complex-envelope domain, following the theory earlier developed by Calandra-Sommariva. On this basis, analytic expressions for the main operating characteristics of the ILA (such as the locking bandwidth under small signal operation) are …