scholarly journals Response of laser-localized structures to external perturbations in coupled semiconductor microcavities

2014 ◽  
Vol 372 (2027) ◽  
pp. 20140004 ◽  
Author(s):  
M. Turconi ◽  
M. Giudici ◽  
S. Barland
Keyword(s):  
Semiconductor Lasers ◽  
Laser Light ◽  
Light Emission ◽  
Localized States ◽  
Time Resolved ◽  
External Perturbations ◽  
Localized Structures ◽  
Coupled Lasers ◽  
The Stability

Laser-localized structures have been observed in several experiments based on broad-area semiconductor lasers. They appear as bounded regions of laser light emission which can exist independently of each other and are expected to be commuted via external optical perturbations. In this work, we perform a statistical analysis of time-resolved commutation experiments in a system of coupled lasers and show the role of wavelength, polarization and pulse energy in the switching process. Furthermore, we also analyse the response of the system outside of the stability region of laser-localized states in search of an excitable response. We observe not only a threshold separating two types of responses, but also a strong variability in the system's trajectory when returning to the initial stable fixed point.

scholarly journals Excitable pulses and diffusion of localized states in a driven semiconductor laser with delay

2018 ◽  
pp. 96-101 ◽  
Author(s):  
Bruno Garbin ◽  
Giovanna Tissoni ◽  
Stephane Barland
Keyword(s):  
Semiconductor Laser ◽  
Semiconductor Lasers ◽  
Optical Feedback ◽  
Optical Injection ◽  
Localized States ◽  
External Perturbations ◽  
Parameter Values ◽  
And Diffusion ◽  
Delayed Optical Feedback

Semiconductor lasers with optical injection may be brought to an “excitable” regime, in which they respond to external perturbations in a neuron-like way. When submitted to delayed optical feedback this system can host stable optical localized states. We characterize experimentally the excitable response of a semiconductor laser with optical injection to external perturbations for different parameter values and show that localized states may diffuse in presence of noise.

Electrically-Induced Light Emission in Polymer-Stabilized Proton Gradient Systems

2019 ◽  
Author(s):  
Jerzy J. Langer ◽  
Ewelina Frąckowiak
Keyword(s):  
Light Emission ◽  
Light Emitting Diode ◽  
Proton Gradient ◽  
Light Emitting ◽  
New Device ◽  
Polymeric Scaffold ◽  
Proton Current ◽  
The Stability ◽  
Polymer Stabilized

<div>Experiments with the chemically generated proton gradient, have lead to fabricate the system which emits the light, when electrically powered, owing to proton current flow. A polymeric scaffold preserves the stability of the system and, at the same time is playing a role of dopants of water, due to chemical character (acidic or basic) of side groups, which are responsible for gradient formation. The</div><div>results of experiments with the chemical model of the proton gradient, the protonic p-n junction, as a light emitting diode, make a “proof of concept”, which opens the way into new light generating process and new device (protonic LED), but also, to general understanding the proton gradient role in</div><div>the light emission processes.</div>

scholarly journals Light emission despite doubly-forbidden radiative transitions in AlP/GaP quantum wells: Role of localized states

2013 ◽  
Vol 114 (16) ◽  
pp. 163101 ◽  
Author(s):  
Sumi Bhuyan ◽  
Richarj Mondal ◽  
Pradip Khatua ◽  
Mykhaylo Semtsiv ◽  
W. T. Masselink ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Light Emission ◽  
Localized States ◽  
Radiative Transitions

Electrically-Induced Light Emission in Polymer-Stabilized Proton Gradient Systems

2019 ◽  
Author(s):  
Jerzy J. Langer ◽  
Ewelina Frąckowiak
Keyword(s):  
Light Emission ◽  
Light Emitting Diode ◽  
Proton Gradient ◽  
Light Emitting ◽  
New Device ◽  
Polymeric Scaffold ◽  
Proton Current ◽  
The Stability ◽  
Polymer Stabilized

<div>Experiments with the chemically generated proton gradient, have lead to fabricate the system which emits the light, when electrically powered, owing to proton current flow. A polymeric scaffold preserves the stability of the system and, at the same time is playing a role of dopants of water, due to chemical character (acidic or basic) of side groups, which are responsible for gradient formation. The</div><div>results of experiments with the chemical model of the proton gradient, the protonic p-n junction, as a light emitting diode, make a “proof of concept”, which opens the way into new light generating process and new device (protonic LED), but also, to general understanding the proton gradient role in</div><div>the light emission processes.</div>

Intense Visible Luminescence from Thermally-Oxidized Porous Silicon

1992 ◽  
Vol 283 ◽  
Author(s):  
S. Miyazakj ◽  
K. Shiba ◽  
K. Sakamoto ◽  
M. Hirose
Keyword(s):  
Porous Silicon ◽  
Light Emission ◽  
Excitation Power ◽  
Thermally Grown Oxide ◽  
Localized States ◽  
Porous Si ◽  
Time Resolved ◽  
Visible Luminescence ◽  
Oxidized Porous Silicon ◽  
The Ideal

ABSTRACTPhotoluminescence from porous silicon oxidized at 800 or 900°C in an N2 +O2 gas mixture has been investigated. The ideal passivation of the porous Si surface with thermally grown oxide results in stable, intense visible-light emission. The steady-state and time-resolved luminescence measured as functions of temperature and excitation power have indicated that a possible pathway for the light emission is the radiative recombination through localized states.

A Statistical Study of Process Variables to Optimize a High Speed Curtain Coater: Part I

TAPPI Journal ◽  
2009 ◽  
Vol 8 (1) ◽  
pp. 20-26 ◽  
Author(s):  
PEEYUSH TRIPATHI ◽  
MARGARET JOYCE ◽  
PAUL D. FLEMING ◽  
MASAHIRO SUGIHARA
Keyword(s):  
Boundary Layer ◽  
Experimental Design ◽  
High Speed ◽  
Statistical Study ◽  
Process Variables ◽  
High Speeds ◽  
The Stability ◽  
Air Removal ◽  
Removal System

Using an experimental design approach, researchers altered process parameters and material prop-erties to stabilize the curtain of a pilot curtain coater at high speeds. Part I of this paper identifies the four significant variables that influence curtain stability. The boundary layer air removal system was critical to the stability of the curtain and base sheet roughness was found to be very important. A shear thinning coating rheology and higher curtain heights improved the curtain stability at high speeds. The sizing of the base sheet affected coverage and cur-tain stability because of its effect on base sheet wettability. The role of surfactant was inconclusive. Part II of this paper will report on further optimization of curtain stability with these four variables using a D-optimal partial-facto-rial design.

The Role of Hydrophobicity in the Stability and pH-Switchability of (RXDX)4 and Coumarin-RXDX Conjugate β-Sheets

2020 ◽  
Author(s):  
Ryan Weber ◽  
Martin McCullagh
Keyword(s):  
Biological Imaging ◽  
Ph Sensing ◽  
Hydrophobic Residue ◽  
Ideal Candidate ◽  
Self Assembling ◽  
Sensing Applications ◽  
Β Sheets ◽  
The Stability ◽  
Dynamics Simulations

<p>pH-switchable, self-assembling materials are of interest in biological imaging and sensing applications. Here we propose that combining the pH-switchability of RXDX (X=Ala, Val, Leu, Ile, Phe) peptides and the optical properties of coumarin creates an ideal candidate for these materials. This suggestion is tested with a thorough set of all-atom molecular dynamics simulations. We first investigate the dependence of pH-switchabiliy on the identity of the hydrophobic residue, X, in the bare (RXDX)<sub>4</sub> systems. Increasing the hydrophobicity stabilizes the fiber which, in turn, reduces the pH-switchabilty of the system. This behavior is found to be somewhat transferable to systems in which a single hydrophobic residue is replaced with a coumarin containing amino acid. In this case, conjugates with X=Ala are found to be unstable and both pHs while conjugates with X=Val, Leu, Ile and Phe are found to form stable β-sheets at least at neutral pH. The (RFDF)<sub>4</sub>-coumarin conjugate is found to have the largest relative entropy value of 0.884 +/- 0.001 between neutral and acidic coumarin ordering distributions. Thus, we posit that coumarin-(RFDF)<sub>4</sub> containing peptide sequences are ideal candidates for pH-sensing bioelectronic materials.</p>

Metal-Metal Cooperative Bond Activation by Heterobimetallic Alkyl, Aryl, and Acetylide PtII/CuI Complexes

2020 ◽  
Author(s):  
Shubham Deolka ◽  
Orestes Rivada Wheelaghan ◽  
Sandra Aristizábal ◽  
Robert Fayzullin ◽  
Shrinwantu Pal ◽  
...  
Keyword(s):  
Alkyl Group ◽  
Bond Activation ◽  
Bond Cleavage ◽  
Terminal Alkyne ◽  
Alkyl Aryl ◽  
Metal Metal ◽  
The Stability ◽  
Selective Formation ◽  
Organoplatinum Compounds

We report selective formation of heterobimetallic PtII/CuI complexes that demonstrate how facile bond activation processes can be achieved by altering reactivity of common organoplatinum compounds through their interaction with another metal center. The interaction of the Cu center with Pt center and with a Pt-bound alkyl group increases the stability of PtMe2 towards undesired rollover cyclometalation. The presence of the CuI center also enables facile transmetalation from electron-deficient tetraarylborate [B(ArF)4]- anion and mild C-H bond cleavage of a terminal alkyne, which was not observed in the absence of an electrophilic Cu center. The DFT study indicates that the role of Cu center acts as a binding site for alkyne substrate, while activating its terminal C-H bond.

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