and whispering galleries are found in applications ranging from sensing, spectroscopy and communications to the generation of laser frequency combs.
#New 2d transistor material made using precision lasers Molybdenum ditelluride (Mote2) is a crystalline compound that
They directed a 1 m wide laser (a human hair is 17 to 181 m) at the 2h-Mote2
#Using lasers to tailor the properties of graphene Carbon nanomaterials display extraordinary physical properties, outstanding among any other substance available,
The researchers from Technological Center AIMEN explore the use of ultrafast lasers as tool for graphene processing.
The laser beam can be focused precisely, used to tailor the properties of graphene films in finely defined areas,
The key is the use of short, highly controlled laser pulses, which will induce chemical changes in the carbon lattice.
It enough a single pulse of laser, with a duration of several picoseconds the time of a single oscillation in a polar molecule, like water.
As the laser spot can be focused in areas of one square micron or less, direct writing of devices on graphene can be done with high precision,
As recently published in AIP Applied Physics Letters("Patterned graphene ablation and two-photon functionalization by picosecond laser pulses in ambient conditions),
"the work of AIMEN researches demonstrated laser based large scale patterning of graphene at high speed and resolution, opening new possibilities for device making.
and chemical processes by adjusting laser beam characteristics. For low energy inputs, multiphoton absorption plays a major role, inducing chemical reactions between carbon
The Laser Applications Centre of AIMEN is devoted to applied research in the field of laser materials processing,
being the largest Spanish laser center in terms of research personnel and investment. The work leading to these results was held within the European FAIERA project, funded by the European union Seventh Framework Programme (GA 316161), under the Research Potential initiative REGPOT in the Capacities Programme a
"This silicon nanodevice can funnel laser light to a tightly focused spot and probe biological molecules to explore their potential use as new drugs.
such as gold and silver, are used in laser light devices because they have the ability to capture individual photons of light.
and optimization of electronic and optoelectronic devices like solar panels and telecommunication lasers. black phosphorus To truly understand the significance of the team's findings,
on a substrate crystal of nonmagnetic strontium titanate using a method pulsed laser deposition developed many years ago for high-temperature superconductors and multicomponent materials by Prof Venkatesan,
and have applications in superresolution microscopy, laser cutting, and particle acceleration.""You generally would need a large optical setup,
By firing two time-delayed, ultrashort laser pulses at a helium atom, the researchers found that the distribution of momentum values for these intersecting electron waves can take the form of a two-armed vortex that resembles a spiral galaxy.
Starace called the pattern an xcellent diagnostic toolfor characterizing electron-manipulating laser pulses which occur on such fast time scales that physicists have sought multiple ways to measure their durations and intensities.
Like all light, laser pulses feature electric fields that normally point in many directions. Polarizing a laser pulse aligns these fields along one direction,
while circularly polarizing a pulse aligns and then essentially rotates the fields around an axis. The team first pulse of circularly polarized light rotated in one direction,
should help inform future investigations involving ultrafast laser physics. ttosecond science is still a new field,
scientists fire an X-ray or extreme ultraviolet laser at a target. The light scatters off, and some of those photons interfere with one another
Over the last ten years, researchers have developed smaller, cheaper machines that pump out coherent, laser-like beams in the laboratory setting.
Zürch and a team of researchers from Jena University used a special, custom-built ultrafast laser that fires extreme ultraviolet photons a hundred times faster than conventional table-top machines.
The ultrafast laser also overcame another drawback of conventional table-top light sources: long exposure times.
when a laser is directed at them, causing the capsule to burst and release its contents.
How hot the gold rods become depends on matching their size with the color of the laser light used.
and by employing different colored lasers. Because the capsules are printed 3d, they can be arranged within the gel in practically any design that can be created on a computer.
noninvasive 3d biomedical imaging photonic chips aerospace photonics micromachines laser tweezing the process of using lasers to trap tiny particles.
he newly demonstrated laser nano-patterning method in graphene oxides holds the key to fast processing and programming of high capacity information for big data sectors.
#Ultrafast lasers offer 3-D micropatterning of biocompatible hydrogels Tufts University biomedical engineers are using low energy,
ultrafast laser technology to make high-resolution, 3-D structures in silk protein hydrogels. The laser-based micropatterning represents a new approach to customized engineering of tissue and biomedical implants.
The work is reported in a paper in PNAS Early Edition published September 15 online before print.
femtosecond laser to generate scalable, high-resolution 3-D voids within silk protein hydrogel, a soft,
Further, the exceptional clarity of the transparent silk gels enabled the laser's photons to be absorbed nearly 1 cm below the surface of the gel-more than 10 times deeper than with other materials
"Because the femtosecond laser pulses allow us to target specific regions without any damage to the immediate surroundings,
No radiation The new fusion process can take place in relatively small laser-fired fusion reactors fuelled by heavy hydrogen (deuterium.
"Generally, most existing techniques to look at single-molecule movements such as optical tweezers have a resolution, at best,
which includes a photovoltaic cell using a high-quality semiconductor crystal similar to the ones for lasers
World-leading optical technologies and ultrashort pulsed laser systems of extreme stability provide the know-how necessary for this study.
rather than solely to the laser's wavelength, demonstrating that the plasmons effectively nudged the electrons in Mos2 into a different energy state."
When the uncovered end of the wire was exposed to a laser, the energy was converted into plasmons, a form of electromagnetic wave that travels through oscillations in electron density.
By scanning the wire bit-by-bit with a laser--a process known as raster scanning--the researchers were able to measure current at each point along the wire,
They also found that the device was sensitive to the laser's excitation wavelength, and performance was limited at shorter wavelengths due to ineffective plasmon propagation and at longer wavelengths due to the band gap of molybdenum disulfide."
Düsseldorf, Mainz, Princeton and Santa barbara, a ring of colloidal particles are localised in optical tweezers and automatically translated on a circular path,
The technique relies on analysis of reflected light from short laser pulses to gain information about magnetization.
the physics of optical diffraction limit how small a laser spot can be used, which ultimately limits the resolution of the technique.
#Soft probing with optical tweezers Surfaces separate outside from inside, control chemical reactions, and regulate the exchange of light, heat, and moisture.
An optical trap is created by a highly focused laser beam and can be used to hold or move miniscule objects.
This displacement is detected by the laser beam scattered at the probe. In this way, the three-dimensional position of the probe is measured one million times per second."
so that the laser beam can jump a step forward for a millisecond, "explains Rohrbach.""Once there, the probe records the scattered light from the surface
the laser beam has trapped it again.""Among other things, the Freiburg researchers have used their technique to scan bacteria,
In the scheme, laser pulses, functioning as three-dimensional lenses in both time and space, can compress electron pulses to attosecond durations and sub-micrometer dimensions,
one can compress electron pulses by as much as two to three orders of magnitude in any dimension or dimensions with experimentally achievable laser pulses.
Wong's team conceived an all-optical scheme that focuses electron pulses in three dimensions by using a special type of laser mode with an intensity"valley"(or minimum) in its transverse profile,
"The pulsed laser modes successively strike the moving electrons at a slanting angle, fashioning a three-dimensional trap for the electrons."
the laser-electron interaction accelerates the back electrons and decelerates the front electrons. As the electrons propagate,
Among their findings is the fact that the longitudinal compression is sensitive to the laser pulse incidence angle,
Since the scheme allows laser pulses to be recycled for further compression of the same electron pulse (not restricted to the same dimension),
one is able to maximize the use of a single laser pulse and to achieve 3d compression with that single pulse.
#4-D laser printing: holograms and beyond Novel tech that manipulates light has applications beyond holograms,
we were able to create something called the direct-write laser scanner (DWLS), which allows us to create nearly perfect geometric phase holograms,
the DWLS"prints"using an ultraviolet laser on a super-thin film--only about 50 nanometers thick.
In other words, a laser can be pointed directly at an object and while the polarization angle may change,
the direction of the laser beam relative to the object stays the same. One reason the DWLS is unique is that it produces geometric phase holograms that are smoothly varying
#Mini X-ray source driven by laser light alone A new method to produce three-dimensional images of soft tissue structures in organisms using laser-generated X-rays
and the Technische Universität München (TUM) have captured three-dimensional images of ultrafine structures in the body of a living organism for the first time with the help of laser-generated X-rays.
By contrast, the laser-driven system in combination with phase-contrast X-ray tomography only requires a university laboratory to view soft tissues.
The paper states,-rays radiated by relativistic electrons driven by well-controlled high-power lasers offer a promising route to a proliferation of this powerful imaging technology.
A laser-driven plasma wave accelerates and wiggles electrons, giving rise to a brilliant kev X-ray emission. his so-called betatron radiation is emitted in a collimated beam with excellent spatial coherence and remarkable spectral stability.
Our results suggest that laser-based X-ray technology offers the potential for filling the large performance gap between synchrotron-and current X-ray tube-based sources.
scientists coupled their technique for generating X-rays from laser pulses with phase-contrast X-ray tomography to visualize tissues in organisms.
The X-rays required were generated by electrons that were accelerated to nearly the speed of light over a distance of approximately one centimeter by laser pulses lasting around 25fs.
The laser pulses have a power of approximately 80tw. By way of comparison: an atomic power plant generates 1, 500mw.
First, the laser pulse ploughs through a plasma consisting of positively charged atomic cores and their electrons like a ship through water, producing a wake of oscillating electrons.
For the first time, the researchers combined their laser-driven X-rays with a phase-contrast imaging method developed by a team headed by Prof.
This laser-based imaging technique enables creation of three-dimensional images of objects. After each X-ray pulse, meaning after each frame,
a laser is used to induce fluorescence. This detection mode is not only highly sensitive, but it can also generate a wide range of information about the type and behavior of the marked biomolecules.
Creating such a spectrum with many individual lasers is technically complex, expensive and less precise than from an integrated source.
the researchers shone laser light into a waveguide, made of silicon nitride, a glass-like material, embedded in regular glass (silicon dioxide).
The shape and construction of the waveguide ensures that the laser light generates new wavelengths as it passes through;
The research was performed by scientists from the Laser Physics and Nonlinear Optics department of UT research institute MESA+(within the strategic research direction Applied Nanophotonics) in collaboration with the Westfälische Wilhelms-Universität (WWU) Münster and the companies Lionix and Xio Photonics.
#Laser array on silicon promises new level of photonic integration Scientists in Belgium are claiming a breakthrough advance for integrated photonics by fabricating an array of laser diodes on a large silicon wafer typical
integrating laser sources on a silicon platform. And while the laser structures have so far only been demonstrated with optical pumping,
the team led by Ghent Dries Van Thourhout suggests that electrical injection-a necessity for true photonic integration-could be achieved readily with the incorporation of a suitable blend of narrow-bandgap semiconductor material in the future.
Van Thourhout and colleagues made an array of distributed feedback (DFB) indium phosphide (Inp) lasers on a 300 mm diameter wafer,
That ability to carefully control the laser wavelengths suggests that the devices ought to be compatible with wavelength division multiplexing (WDM) schemes that are used widely in today optical communications systems.
Add to that a very high-yielding process (the team claims that at least 98 per cent of more than 200 devices characterized so far have showed laser operation)
Learning from recent attempts to combine III-V and silicon materials in Finfet electronic devices, the Belgian team grew their laser structures directly onto a standard silicon wafer.
we fabricated DFB lasers exhibiting robust single-mode operation. Thin buffer layer crucial The usual way to overcome the lattice mismatch between silicon
The result was an Inp-on-silicon array of DFB lasers emitting at between 915 nm
YAG laser provided by Ekspla. Although that is not the ideal lasing wavelength for silicon waveguides,
Van Thourhout and colleagues outlined how these challenges could be met. he in-plane laser configuration employed makes it straightforward to adopt well-studied electrical injection schemes,
it is even possible to envisage butt-coupling the lasers to optical waveguides defined at the same level. n addition,
direct contact of the III lasers with silicon-on-insulator (SOI) wafers will improve the thermal dissipation of the device,
on-chip lasers that could be produced using the approach, concluding that: n particular, for on-chip optical interconnects, the demonstrated monolithic laser array,
together with the WDM technology, may finally pave the way to terascale computing. Photonic integrated circuits (PICS) based on the technology could dramatically change the architecture of fiber-optic transceivers used in data center optical interconnects, by pushing down the cost of chip-level data transfer between logic and memory devices.
Importantly, the laser integration work was carried out in IMEC 300mm CMOS pilot line facility, providing a path to large volume manufacturing
IMEC says that efforts are focused now on growing the more complex semiconductor layer stacks needed for electrical injection of the lasers and emission in the 1300 nm wavelength range d
#Microscale 3d'Bar codes'Readable with Lasers Microscale indentations that can be read by laser scanners serve as 3d bar codes that could help distinguish between genuine and counterfeit goods. A prototype device for creating the bar codes has been developed by Sofmat Ltd
and a laser-scanning confocal microscope to characterize the surface of the coded product and ensure the code is reproduced accurately."
"A laser scanner is in development that will be able to read the code and wirelessly transmit the result to mobile devices.
Because of the newfound clarity of the material, it could also work in lasers, protecting the components inside a directed energy weapon from the ravages of sea or sand while still letting the laser shine through.
Now that the Navy has developed a reliable means of manufacturing the material, the next step is handing it off to industry and seeing
AVERT's deployment unit can scan locations of a targeted vehicle using laser-based LIDAR,
#Boeing Just Patented A Force field Made Of Lasers So, Boeing just patented a force field. Technically, the patent is for a ethod and system for shockwave attenuation via electromagnetic arc,
Next, the signal from the sensor triggers a laser (or a blast of electricity or microwave energy) that heats up a section of air or water
The liquid metal could be used to build self contained pumps that don't require outside power or batteries, saving on weight and complexity for items like night vision and laser cooling pumps.
But a quick laser scan could prove a product origin, which the engineers say could track
Prototype on-chip networks have used semiconductor lasers as light emitters. They can modulate very quickly,
What's more, semiconductor lasers are not particularly efficient. They produce a lot of heat along with light
In this initial experiment, the researchers used a laser to zap the VO2 and cause it to change phase.
A faster means of changing the VO2 phase--perhaps using electricity instead of a laser--could make the system much faster still.
Specifically, the research team used the surface waves of Linbo3 to listen to how the illumination of Linbo3 by laser light changes the electric properties of Mos2. he tone at
and infer how much current the laser light allowed to flow in the Mos2. We also fabricated transistor structures onto the Mos2 films
After creating the tattoo-like designs on a computer, a laser cutter traces out the design
while testing a laser-based measurement technique that they recently developed to look for what is called multipolar order. o understand multipolar order,
When you shine a red laser pointer at a wall, for example, your eye detects red light.?However, for all materials, there is a tiny amount of light bouncing off at integer multiples of the incoming frequency.
So with the red laser pointer, there will also be some blue light bouncing off of the wall.
This scans the print with a laser, particles in the powder are ionised vaporised and, and a molecular profile appears.
pulses of a laser can be sent down the guide, where they can interact with the GST
The new device, called a biophotonic laser-assisted surgery tool, or BLAST, is a silicon chip with an array of micrometer-wide holes,
Researchers use a laser pulse to heat the titanium coating, which instantly boils the water layer adjacent to parts of the cell.
A laser can scan the entire silicon chip in about 10 seconds. Chiou said the key to the technique's success is the instantaneous and precise incision of the cell membrane."
To do this, the researchers used a combination of ultrafast pulse-shaped laser excitation and highly sensitive electrical readout.
Supporting data were collected with two-dimensional infrared spectroscopy, an advanced laser technique that combines ultrafast time resolution with high sensitivity to chemical structure.
#Printing silicon on paper, with lasers Recently, a group of researchers at Delft University of Technology,
to be produced directly on a substrate from liquid silicon ink with a single laser pulse--potentially ousting its pale usurpers.
Then we annealed the layer with an excimer laser a conventional tool used for manufacturing smartphone displays.
The laser blast only lasted a few tens of nanoseconds, leaving the paper completely intact. In testing its conductive performance,
Ishihara and his colleagues found that thin-film transistors using the laser-printed layer exhibited mobilities as high as those of conventional poly-silicon conductors.
An efficient terahertz emission from two-dimensional arrays of gold split-ring resonator metamaterials was discovered as a result of excitation by a near-infrared pulsed laser.
when a two-dimensional array of nanometer-sized gold metamaterial resonators is illuminated by a tunable near-infrared femtosecond laser,
#Generating broadband terahertz radiation from a microplasma in air Researchers have shown that a laser-generated microplasma in air can be used as a source of broadband terahertz radiation.
They demonstrate that an approach for generating terahertz waves using intense laser pulses in air can be done with much lower power lasers, a major challenge until now.
They have exploited the underlying physics to reduce the necessary laser power for plasma generation. Researchers at the University of Rochester's Institute of Optics have shown that a laser-generated microplasma in air can be used as a source of broadband terahertz radiation.
In a paper published this week in Optica Fabrizio Buccheri and Xi-Cheng Zhang demonstrate that an approach for generating terahertz waves using intense laser pulses in air--first pioneered in 1993--can be done with much lower power lasers, a major challenge until now.
Ph d. student and lead author Buccheri explains that they exploited the underlying physics to reduce the necessary laser power for plasma generation.
He adds that it could potentially be improved for applications in the monitoring of explosives or drugs.
He adds that this can be generated using specific terahertz devices, such as diodes or lasers. However, for spectroscopy applications,
"Until now, approaches to use a plasma as a broadband source of terahertz have used commonly an elongated plasma generated by combining together two laser beams of different frequencies, i e.,
requires powerful, expensive lasers. The"one-color"approach uses single laser frequency to generate the plasma.
Pioneered by Harald Hamster and colleagues in 1993, it required even higher laser energies and therefore it was explored not further until this recent paper by Buccheri and Zhang.
Buccheri explains that he has always been interested in the polarization of light and how it can be exploited for different uses.
if by creating a plasma with a laser in one of these"weirder"polarization states
"He adds that he was then able to exploit the physics to use lower laser energies than previously thought possible to generate broadband terahertz waves in air.
He thinks that fine tuning the type of laser used and changing the air to a different gas could enable even lower operation powers.
An advantage of this"one-color"approach to generating terahertz radiation is the fact that the terahertz waves propagate in a different direction to the laser beam.
#Scientists develop first liquid nanolaser To understand the concept, imagine a laser pointer whose color can be changed simply by changing the liquid inside it,
instead of needing a different laser pointer for every desired Color in addition to changing color in real time, the liquid nanolaser has additional advantages over other nanolasers:
it is simple to make, inexpensive to produce and operates at room temperature. Nanoscopic lasers--first demonstrated in 2009--are only found in research labs today.
They are, however, of great interest for advances in technology and for military applications.""Our study allows us to think about new laser designs
and what could be possible if they could actually be made, "said Teri W. Odom, who led the research."
"My lab likes to go after new materials, new structures and new ways of putting them together to achieve things not yet imagined.
The liquid nanolaser in this study is not a laser pointer but a laser device on a chip,
The laser's color can be changed in real time when the liquid dye in the microfluidic channel above the laser's cavity is changed.
The laser's cavity is made up of an array of reflective gold nanoparticles, where the light is concentrated around each nanoparticle
and then amplified. In contrast to conventional laser cavities, no mirrors are required for the light to bounce back and forth.
Notably, as the laser color is tuned, the nanoparticle cavity stays fixed and does not change;
only the liquid gain around the nanoparticles changes. The main advantages of very small lasers are:
Some technical backgroundplasmon lasers are promising nanoscale coherent sources of optical fields because they support ultra-small sizes and show ultra-fast dynamics.
Although plasmon lasers have been demonstrated at different spectral ranges, from the ultraviolet to near-infrared, a systematic approach to manipulate the lasing emission wavelength in real time has not been possible.
The main limitation is that only solid gain materials have been used in previous work on plasmon nanolasers;
hence, fixed wavelengths were shown because solid materials cannot easily be modified. Odom's research team has found a way to integrate liquid gain materials with gold nanoparticle arrays to achieve nanoscale plasmon lasing that can be tuned dynamical, reversibly and in real time.
These nanoscale lasers can be mass-produced with emission wavelengths over the entire gain bandwidth of the dye.
Thus, the same fixed nanocavity structure (the same gold nanoparticle array) can exhibit lasing wavelengths that can be tuned over 50 nanometers, from 860 to 910 nanometers,
In the recent years, the radiation pressure has been harnessed also in the field of laser physics. It can be used to couple the electromagnetic laser field to, for example,
the movement of the small mechanical oscillators that can be found inside ordinary watches. Due to the weakness of the interaction, one typically needs substantially strong laser fields."
"Radiation pressure physics in these systems have become measurable only when the oscillator is hit by millions of photons,
and a laser diode, all enclosed in a small, 3d-printed case and integrated to act just like a fluorescence microscope.
Conversely, the CLS is a miniature version of a synchrotron that produces suitable X-rays by colliding laser light with electrons circulating in a desk-sized storage ring.
The technique complements ultrafast studies with SLAC's X-ray free-electron laser. Similar to X-ray light, highly energetic electrons can take snapshots of the interior of materials as they pass through them.
The superior performance of the new UED system is due to a very stable"electron gun"originally developed for SLAC's X-ray laser Linac Coherent Light source (LCLS), a DOE Office of Science User Facility.
for instance in response to ultrashort laser pulses.""UED has been under development for the past 10 to 15 years,
"LCLS expertise in electron gun technology and ultrafast laser systems gives our system the performance and stability needed to study much faster processes."
when laser science and X-ray science merged into the new field of ultrafast X-ray science."
#New 2d transistor material made using precision lasers Last year a multi-discipline research team led by South korea's Institute for Basic Science (IBS) Center for Integrated Nanostructure Physics
They directed a 1 m wide laser (a human hair is 17 to 181 m) at the 2h-Mote2
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