Light pulse propagation. Medical search. Frequent questions

In order to provide a spectral supercontinuum instead of discrete harmonic peaks, as well as allow the production of isolated attosecond pulses and therefore considerably improve the temporal resolution, the use of few-cycle SWIR pulses to drive SXR HHG has recently been developed. (nature.com)
Molecular wave packets offer a means of shaping attosecond pulses. (canada.ca)
Attosecond pulses created by high-order harmonic generation in gases often exhibit strong chromatic aberrations, arising from the broad bandwidth and wavelength-dependent nonlinear light-matter interaction. (lu.se)
When the driving laser intensity varies spatially, as for Gaussian driving beams, the apparent source position of the harmonics differs significantly from one order to the next, thus affecting the achievable intensity and duration of the attosecond pulses when they are focused on a target. (lu.se)
We observe that controlling chromatic aberrations by flat-top spatial shaping strongly reduces the variation of the XUV spectrum on the beam axis during propagation and, in return, the longitudinal sensitivity of both the temporal profiles and the temporal shifts of the focused attosecond pulses. (lu.se)

citation needed] In 2002, he and undergraduate student Louis Poirier transmitted faster-than-light electrical pulses through a 120-metre long "photonic crystal" made of coaxial cables of alternating characteristic impedance (12 pairs of 50 Ω and 75 Ω cables). (wikipedia.org)
The research activity concerns the development of solid state lasers and integrated photonic devices for application to environmental monitoring, telecommunications and coherent control of light. (polimi.it)

It should be noted that alternative devices have also been proposed, including interband and quantum cascade lasers (achieving 100s ns pulses) 9 and the nonlinear frequency conversion of near-IR sources (e.g., offering nanojoule-level femtosecond pulses through Raman-shifted fiber sources 10 and microjoule few-cycle pulses using bulk optical parametric chirped pulse amplification, OPCPA 11 ). (aip.org)

When we theoretically investigate interaction of an intense and ultrashort laser pulse with solids, there are two aspects that should be considered: the strong electric field of the light pulse induces nonlinear electron dynamics in solids, and the nonlinear polarization that arises from the electron dynamics affects the propagation of the light pulse. (mpg.de)

Precision ultrasonic thickness gages usually operate at frequencies between 500 KHz and 20 MHz, using broadband, well damped piezoelectric transducers that when excited by electrical pulses generate bursts of sound waves, and in receiving mode convert sound waves back into electrical pulses. (olympus-ims.com)

We present a table-top beamline providing a soft X-ray supercontinuum extending up to 370 eV from high-order harmonic generation with sub-13 fs 1300 nm driving pulses and simultaneous production of sub-5 fs pulses centered at 800 nm. (nature.com)

In my talk, I would like to show several recent progresses of our approach: (1) oblique irradiation of a strong laser pulse on thin dielectric film, (2) pump-probe calculation for the generation of coherent optical phonon and amplification of the impulsively stimulated Raman scattering wave [2], and (3) a unified description for interaction of intense light pulse with thin materials, from mono-atomic layer to thick films [3]. (mpg.de)
An international team of researchers from the University of Cologne (Germany), Radboud University Nijmegen (The Netherlands), the Ioffe Institute and the Prokhorov General Physics Institute (Russia) has discovered a new mechanism to control spin-lattice interaction using ultrashort terahertz (THz) pulses (terahertz means 1012 hertz). (eurekalert.org)
At the same time, the weak interaction makes control over propagation of the spin waves challenging. (eurekalert.org)
Using a thin sample, however, means that the interaction of the probe pulse with photoinjected charge carriers causes small changes in the pulse's electric field. (attoworld.de)
The interaction of the radiation with the medium along the propagation path strongly depends on the type and microphysical properties of the specific meteorological formation as well as on the energy parameters of the beam, the structure of the beam, the temporal regime, and the conditions of focusing. (spie.org)
Light propagation in anisotropic materials, · Acusto-optical effects and modulators, · Electro-optical effects and modulators, · Non-linear interaction between light and matter, · Ultrafast optics, propagation of short laser pulses in dispersive non-linear media, · Basic laser safety. (lu.se)
With the rise of femtosecond lasers, it is now possible to achieve resolution down to tens of femtoseconds, allowing the investigation of the interaction between charge and phonons, and the propagation of sound waves with a spatial resolution below the nanometer. (lu.se)
On top of that, oscillations can be seen: they are cause by the interaction of light with coherent phonons. (lu.se)
Coherent phonons are a result of the interaction of light with electron and lattice. (lu.se)

Studies of acoustic waves generated by pulsed irradiation of melanosomes and pigmented cells support this possibility. (medscape.com)
With the rapid development of short-pulse intense laser sources, studies of matter under extreme irradiation conditions enter further unexplored regimes. (lu.se)

Fiber gratings and periodic optical structures for coherent control of light. (polimi.it)
Localized Dispersive States in Nonlinear Coupled Mode Equations for Light Propagation in Fiber Bragg Gratings. (upm.es)
Dispersion effects induce new instabilities and dynamics in the weakly nonlinear description of light propagation in fiber Bragg gratings. (upm.es)

A new family of dispersive localized pulses that propagate with the group velocity is numerically found, and its stability is also analyzed. (upm.es)

The Floquet state, which is a periodically and intensely light-driven quantum state in solids, has been attracting attention as a novel state that is coherently controllable on an ultrafast time scale. (nature.com)
We did what is typically done in ultrafast physics: in addition to the intense injection pulse, we employed a second, much weaker probe pulse to see how the newly created charge carriers respond to its electric field. (attoworld.de)
In the mode-locking operation, ultrafast lasers with a high signal-to-noise ratio (70 dB), a pulse width as narrow as 265 fs and a repetition rate of 49.51 MHz were acquired. (bvsalud.org)

The main diagnostic principles are related to the analysis of fluorescence emission and propagation of optical radiation in highly diffusive media. (polimi.it)
The propagation of pulsed laser radiation along the atmospheric ground paths containing droplet aerosols (fog, drizzle, rain) belongs to a class of problems in nonlinear optics in which the multiple-factor nature and nonadditivity of the processes affecting the transmission of the radiation channel are strongly pronounced. (spie.org)
A Monte Carlo procedure to deal with propagation of radiation in a turbid medium presenting some simple kinds of inhomogeneity is briefly outlined. (spie.org)
Propagation of High Energy Pulses of 10.6 micrometer Radiation through the Atmosphere. (dtic.mil)

To describe the propagation of the intense light pulse, it is necessary to calculate simultaneously the propagation of the light electromagnetic fields and the electron dynamics. (mpg.de)
An electromagnetic pulse propagating through air or vacuum does not change shape, but one propagating through material may significantly alter shape with distance of propagatIOn. (earthdoc.org)
The velocity of electromagnetic propagation in a material is determined by the speed of light in vacuum divided by the square root of the product of permittivity and permeability. (earthdoc.org)
This new telecommunication system works on low loss electromagnetic wave propagation modes which allow it to provide quality ra. (cdc.gov)
A new postdisaster communication and location system using through-the-earth electromagnetic wave propagation was tested at the Bureau of Mines Lake Lynn Experimental Mine. (cdc.gov)

Coherent light can be generated at these short wavelengths using synchrotron laser sources, or the new free-electron lasers such as the (under construction) Linac Coherent Light Source (Menlo Park, CA). However, again these are very large-scale light sources, of which only a few will ever be built. (laserfocusworld.com)
Erbium-doped and holmium-doped fluoride fiber lasers incorporating a saturable absorber are emerging as promising pulse sources for 2.7-2.9 μm, yet it remains a major challenge to extend this coverage. (aip.org)
7,8 Mode-locked mid-IR fiber lasers to date, however, have only scratched the surface of the mid-IR region, failing to satisfy the need for flexible short-pulse sources beyond 3 μm. (aip.org)
Diels and Arissian are co-authors of many research papers and the textbook " Lasers: The Power and Precision of Light ," named a CHOICE Outstanding Academic Title in the Engineering category in 2012. (unm.edu)
The aim of the course is develop the students' knowledge of light and lasers and to provide methods for describing different characteristics and how these characteristics can be manipulated. (lu.se)
For simplicity and in an effort to avoid confusion, this article generally refers to lasers based on their pulse duration and focuses on common laser-based treatment modalities. (medscape.com)
In addition, an application of X-ray Free-Electron Lasers (XFELs) delivering intense femtosecond X-ray pulses, allows to investigate sample evolution in IR pump - X-ray probe experiments with an unprecedented time resolution. (lu.se)

The bound-state pulses are formed by doubling identical solitons with a temporal interval of 0.8 ps. (bvsalud.org)

Mode-locked fiber laser technology to date has been limited to sub-3 μm wavelengths despite significant application-driven demand for compact picosecond and femtosecond pulse sources at longer wavelengths. (aip.org)
2 In terms of mode-locking mechanisms, real saturable absorbers (SAs) such as semiconductor films 3-5 and nanomaterials 6 have been employed to generate self-starting picosecond pulses, while pulse durations as short as 180 fs (with energies exceeding 7 nJ) have been achieved using nonlinear polarization evolution (NPE-an artificial SA) in ring cavity designs. (aip.org)

In the case of acoustic phonons, this leads to different behavior: coherent acoustic phonons, also called sound waves, are used for ultrasonic imaging, while incoherent acoustic phonons are responsible for heat propagation in semiconductors and insulators. (lu.se)

One technique is light scattering spectroscopy, which offers an important clue to clarifying the symmetries and energy structures of the states through symmetry analysis of the polarization selection rules. (nature.com)
Here, we determine circular and linear polarization selection rules of light scattering in a mid-infrared-driven Floquet system in monolayer MoS 2 and provide a comprehensive understanding in terms of the "dynamical symmetry" of the Floquet state. (nature.com)
Compared with HHG, tuning of the polarization and frequency of the probe light may provide more detailed information about the symmetries and electronic structures. (nature.com)
It has been experimentally confirmed that DSs govern the band crossings of surface electrons in a light-driven topological insulator 3 and determines the polarization selection rules for HHG in a circularly polarized light-driven crystalline solid 15 . (nature.com)
We controlled the polarizations of the MIR and NIR pulses by using liquid crystal retarders and resolved the polarization of the sidebands by using wave plates and polarizers. (nature.com)
By taking advantage of the polarization gating technique with 12 fs, 1800 nm pulses, and the appropriate choice of metallic filters to compensate for the SXR dispersion 21 , an isolated pulse of 53 attoseconds extending above 300 eV was measured 22 . (nature.com)
assess and find optical methods to develop new advanced technological applications, methods and systems based on polarization, non-linear, optics, acousto-optics, electro-optics, coherence and ultrashort pulses. (lu.se)

Field patterns can describe the propagation of the pulse along characteristic lines with a fixed slope in each square, which is governed by the refractive properties of each square. (utah.edu)

Specific projects utilising the slow light phenomenon are laser frequency stabilization and medical imaging. (lu.se)

Using a simple linear cavity with an acousto-optic tunable filter, we generate ∼33 ps pulses with up to 2.7 nJ energy and 330 nm tunability from 2.97 to 3.30 μm (∼3000-3400 cm −1 )-the first mode-locked fiber laser to cover this spectral region and the most broadly tunable pulsed fiber laser to date. (aip.org)
ZBLAN) fiber doped with erbium (Er) and holmium (Ho) ions to generate pulses in the 2.7-2.9 μm range. (aip.org)
Furthermore, the RexNb(1-x)S2-based device is used to generate ultrashort pulses in an erbium-doped fiber (EDF) laser cavity. (bvsalud.org)

After incorporating it into an Er-doped fiber laser, dissipative soliton laser pulses are readily obtained with a fundamental frequency of 43.5 MHz. (bvsalud.org)

Also, this medium indicates itself as self-phase modulation, a self-encouraged phase, and frequency-shift of a pulse of light as it travels toward a fiber nonlinearity. (hindawi.com)
The time-dependent backscattered linear fields depend upon: (1) the linewidth of the pulse and the linewidth of the resonance of the sphere, and (2) the frequency separation between the center frequency of the pulse and the resonance frequency of the sphere. (spie.org)
It involves comparing two paths (sample and reference) of single frequency or multi-color light. (unm.edu)
Both scattering processes are excited by a pulsed frequency-doubled Nd-YAG laser at a wavelength of 532 nm with a repetition rate of 10 Hz and a pulse width of 10 ns (FWHM). (aiche.org)
Thus, the velocity of propagation is frequency dependent. (earthdoc.org)
In wet soils, this usually results in higher frequency components of a pulse attenuating and propagating faster than the lower frequency components, resulting in pulse broadening. (earthdoc.org)
During transmitting each subaperture transmits a chirp pulse at a different carrier frequency, while during receiving every subaperture receives the scattered pulses at the same time. (hindawi.com)
The pulse width is 285 fs, and the repetition frequency is 61.993 MHz. (bvsalud.org)
For example changing the transmission window frequency with changes the speed of light in the material. (lu.se)

In nonlinear optics, bright light from a laser is incident on a material. (laserfocusworld.com)

We have built an imaging solution that allows us to visualize propagation of light at an effective rate of one trillion frames per second. (weblogsky.com)
Figure 1: Using our custom time of flight camera, we are able to visualize light sweeping over the scene. (mit.edu)

Light can propagate through a superlens along characteristic lines such that two objects, placed too close together to discern with a microscope, can be viewed as separate. (utah.edu)

ħω MIR = 0.26 eV, pulse duration: 60 fs) to create a Floquet state in monolayer MoS 2 . (nature.com)
ħω NIR = 1.55 eV, pulse duration: 110 fs) into the MIR-driven system. (nature.com)
In the Q-switching state, the narrowest pulse duration was measured as 1.756 µs with a maximum single-pulse energy of 221.95 nJ and a signal-to-noise ratio of 60 dB. (bvsalud.org)

By photoinjecting charge carriers, an extremely short laser pulse can increase the electric conductivity of a medium by many orders of magnitude within just a few femtoseconds. (attoworld.de)
When the refractive index or absorption of the sphere is intensity-dependent, then the backscattering also depends upon the intensity of the laser pulse. (spie.org)
When the droplets have a large intensity- dependent index of refraction or a large saturable absorption, and are illuminated near a resonance with a high-intensity laser pulse, hysteresis may be seen in the back-scattered intensity. (spie.org)
When a laser pulse is absorbed, it deposits its energy in the material. (lu.se)

Hasegawa and Tappert realized in 1973 that the same NLS equation governs pulse propagation inside optical fibers. (hindawi.com)

Numerical simulations show excellent agreement with experiments and also offer new insights into the underlying dynamics of FSF pulse generation. (aip.org)

The common feature of all methods of investigation is the development of novel instruments aimed at the measurement of light with high temporal resolution and sensitivity. (polimi.it)

The false-color, near-infrared light photos are from Hubble's Wide Field Camera 3. (scitechdaily.com)

Indeed, the 9 fs output of an optical parametric chirped pulse amplifier centered at 1600 nm generated a SXR continuum up to 350 eV in neon 20 . (nature.com)

This gradient leads to thermal expansion and the generation and propagation of acoustic waves, which can mechanically damage the melanosome-laden cells. (medscape.com)

otherwise, various propagation effects would have caused very nontrivial distortions in the electric field of the transmitted probe pulse. (attoworld.de)
The report contains a detailed theoretical discussion of the effect of CO2 laser 10.6 micrometer wavelength energy on fog droplets, and the subsequent effects on the optical propagation path of the laser beam. (dtic.mil)

This mechanism can open up new and elegant ways to control propagation of spin waves and thus make an important step to conceptually new technologies of data processing in future. (eurekalert.org)
He imagined (1893) that he is running fast after a wave of light, and when he caught up with it he saw frozen waves. (sciforums.com)
Long distance propagation of radio waves depends on an invisible layer of charged particles, which envelops the Earth. (vigyanprasar.gov.in)
Because of the way light waves move through hyperbolic metamaterials, they can be used as superlenses to view objects too small to be seen with other microscopy methods. (utah.edu)

Since the early days of quantum mechanics, scientists have been exploring what exactly happens during photoionization and photoinjection, when an electron gains enough energy from a light wave to free itself from atomic or molecular orbitals. (attoworld.de)
The most important result is that we now know how to perform and analyze such experiments and that we indeed saw the light-driven electron motion as no one could do before I would argue that we've just scratched the surface of what pump-probe field-resolved measurements can do. (attoworld.de)

Both experimental data and theory modeling show that the periodicity in the sample survives to a large extent the extreme excitation and shock wave propagation inside the colloidal crystal. (lu.se)

At the temporal (or spectral) level, a short pulse entering a scattering medium will see its length greatly extended due to the multiplicity of possible path length light can take before exiting the medium. (ens.fr)

This phenomenon, called pulsed accretion, has been seen in later stages of star birth, but never in such a young system or with such intensity and regularity. (scitechdaily.com)

To achieve a nonperturbative regime without damaging the monolayer, we set the photon energy of the pulses to a much lower energy than the bandgap energy of the monolayer (1.8 eV) 11 . (nature.com)
Things get more complicated when no photon in the light wave has enough energy to do so. (attoworld.de)

The course sets out to provide a basic understanding of optical transmission systems concentrating on light propagation along fibres and light processing using fibre- and planar waveguide-based devises. (edu.au)

Feasibility tests at ID15 and ID19 have already demonstrated that the pulsed time-structure of the ESRF's synchrotron light can be used to capture snapshot images of ultra-fast processes such as crack propagation, shown in Figure 50 . (esrf.fr)
The research activity concerns the development of new laser sources for the generation of ultrashort optical pulses (in the femtosecond regime) and their application to the study of dynamical processes in materials. (polimi.it)

Here, we examine light scattering in a Floquet system by injecting an additional probe pulse. (nature.com)
What makes our experiment very special is that we measured the time-dependent electric field of the probe pulse, and we did so using a new technique that we had developed for this purpose. (attoworld.de)

Astronomers propose the light flashes are caused by periodic interactions between two newly formed stars that are binary, or gravitationally bound to each other. (scitechdaily.com)

If the filter is narrow it will slow down the speed of propagation significantly. (lu.se)

A pulse-echo ultrasonic thickness gage determines the thickness of a part or structure by accurately measuring the time required for the short ultrasonic pulse generated by a transducer to travel through the thickness of the material, reflect from the back or inside surface, and return to the transducer. (olympus-ims.com)

This speed represents the group velocity, but the amplitude of the signal also drops in such a way that the energy transmitted never exceeds, at any given time, the energy that would have been transmitted by same pulse travelling in a vacuum. (wikipedia.org)
Time series recording crack propagation in a glass plate initiated by an accelerated bolt. (esrf.fr)
In the common case of measurements involving direct contact transducers, the zero offset compensates for the transit time of the sound pulse through the transducer's wearplate and the couplant layer, as well as any electronic switching time or cable delays. (olympus-ims.com)
As a disturbance, such as a pulse of laser light, moves forward in time, it spreads out over space, encountering boundaries between materials in space and then in time as the materials switch properties/colors with each successive row. (utah.edu)
The time slots correspond to the true geometry of the scene (light travels 1 foot in a nanosecond, times are for round-trip). (mit.edu)
With this modification, we show that we can not only address multipath interference but also enable new applications such as recovering depth of near-transparent surfaces, looking through diffusers and creating time-profile movies of sweeping light. (mit.edu)
Our key idea is to formulate the forward amplitude modulated light propagation as a convolution with custom codes, record samples by introducing a simple sequence of electronic time delays, and perform sparse deconvolution to recover sequences of Diracs that correspond to multipath returns. (mit.edu)
This is simply the time it takes for a packet to travel between one place and another at the speed of light. (streamingpulse.com)
Current technologies for locating trapped miners from the surface are either simple direction finders or time difference pulse systems that have accuracy limitations. (cdc.gov)

The scientists then 'drive' the spin-lattice coupling by applying an ultrashort terahertz pulse. (eurekalert.org)
Chemical Exchange Saturation Transfer and Arterial Spin Labeling: How Similar Pulse Sequences detect Different Phenomena. (lu.se)

The Floquet theoretical approach is useful for describing strong light-matter interactions at energy scales beyond which perturbation theory works 8 . (nature.com)
A sharp decay of the signal is induced by the absorption of the light and the signal slowly rise back to its original value through different interactions. (lu.se)

It features propagation delay and error injection/ alarm generation. (lawfuel.com)

Even with this method, measurements took many hours, during which the pulses would change a bit. (attoworld.de)
By several mirrors, plano-concave and convex lenses, the laser beam is focused into the center of reactor either as a light sheet for the PIV measurements or as a point for the Raman experiments. (aiche.org)

Building on this success, there is currently a strong demand to extend the wavelengths of these compact high-brightness pulse sources into the mid-infrared (mid-IR), to enable a range of new applications such as breath analysis, laser surgery, and polymer processing, which exploit absorption resonances of important organic molecules and technical materials in this region. (aip.org)
However, they are geared to measure range (or phase) for a single reflected bounce of light and suffer from systematic errors due to multipath interference. (mit.edu)
On the other hand, the range resolution, determined by the pulse bandwidth, has to be increased to match the azimuth resolution. (hindawi.com)

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