Commonly, femtosecond-short shutter speeds are provided by short-pulse laser technology, but laser light is not able to spatially resolve atoms.
Scientists from the Laboratory for Attosecond Physics at LMU and MPQ have succeeded now in producing ultrashort electron pulses with a duration of only 28 femtoseconds.
an optical laser pulse is sent to the sample, initiating a response. Shortly afterwards the electron pulses produce a diffraction image of the structure at a sharp instant in time.
A large amount of such snapshots at varying delay times between the initiating laser pulses and the electron pulses then results in a film showing the atomic motion within the substance.
#Silicon photonics takes the next step toward a high-bandwidth future The computing and telecommunications industries have ambitious plans for the future:
They established a method to integrate silicon photonic chips with the processor in the same package,
"IBM has been a pioneer in the area of CMOS integrated silicon photonics for more than 12 years,
"said Bert Offrein, manager of the photonics group at IBM Research-Zurich.""In addition to the silicon technology advancements at the chip-level, novel system-level integration concepts are required also to fully profit from the new capabilities silicon photonics will bring,
"he continued. Optical interconnect technology is incorporated currently into data centers by attaching discrete transceivers or active optical cables,
the United states and Japan instead proposed an integration scheme in which the silicon photonic chips are treated similarly to ordinary silicon processor chips
Challenges arise because alignment tolerances in photonics are critical (sub-micron range) and optical interfaces are sensitive to debris and imperfections,
and enables the simultaneous interfacing of many optical connections between a silicon photonic chip and the system.
"This integration scheme has the potential to massively reduce the cost of applying silicon photonics optical interconnects in computing systems,
then used lasers to cool them to within a few degrees of absolute zero. These are the key prerequisites for making an object behave according to quantum principles.
Widely-used technologies, such as laser cooling, that work for atoms won't work for such large objects,
During cavity cooling, a particle is suspended by a laser light field contained between two mirrors, which has a very carefully calibrated wavelength.
The laser light can hold the particle steady (a phenomenon known as optical tweezing) and draw motional energy out of it at the same time.
However since the laser light can sometimes actually heat the objects up this method has not been shown to work before."
"Our solution was to combine the laser beam that cools the glass particle with an electric field
"The electric field also gently moves the glass particle around inside the laser beam, helping it lose temperature more effectively."
and inhibiting stimulated Brillouin scattering in photonic integrated circuits")."from left: Professor Benjamin Eggleton, Thomas Bttner and Moritz Merklein, researchers from CUDOS at the University of Sydney with the chalcogenide photonic chip.
This breakthrough is a fundamental advance for research in photonic chips and optical communications, said Moritz Merklein,
lead author from the Universitys School of Physics. In optical communications systems optical nonlinearities are regarded often as a nuisance,
Importantly our experiments were performed in a photonic chip. To achieve their result the scientists investigated a specific optical nonlinearity that deals with the interaction between light
and developing certain types of lasers. So we have shown that we can selectively enhance or inhibit this interaction,
When the laser wavelength is tuned close to the edge of the bandgap the speed of light is reduced. This will greatly enhance the optical nonlinearity.
The team's next step is to use the same strategy for increasing the material's light absorption abilities to create a better material for solar cells and photodetectors."
"By shooting it with a laser beam, we were able to read out the ion that was excited in this way,
atomlike energy levels that can be probed using green laser light. Like atomic systems, the NV centers can be used as a qubit.
Like any good sensor, the NV centers are almost completely non-invasivetheir read-out with laser light does not disturb the sample they are sensing.
onl prweb About PI PI is a leading manufacturer of precision motion control equipment, piezo motors, air bearing stages and hexapod parallel-kinematics for semiconductor applications, photonics, bio-nano-technology and medical engineering.
Probing a nitrogen vacancy requires zapping it with laser light, which it absorbs and re-emits.
only a small fraction of the pump light was used to excite a small fraction of the NVS,
the Jamieson Career development Assistant professor in Electrical engineering and Computer science and one of the designers of the new device. e make use of almost all the pump light to measure almost all of the NVS.
have demonstrated now that a graphene-based photodetector converts absorbed light into an electrical voltage at an extremely high speed.
To do this, the researchers used a combination of ultrafast pulse-shaped laser excitation and highly sensitive electrical readout.
As Klaas-Jan Tielrooij comments,"the experiment uniquely combined the ultrafast pulse shaping expertise obtained from single molecule ultrafast photonics with the expertise in graphene electronics.
Koppens comments,"Graphene photodetectors keep showing fascinating performances addressing a wide range of applications
#Lanthanide-organic framework nanothermometers prepared by spray-drying A work in Advanced Functional Materials shows how spray-drying prepared MOF nanoparticles containing lanthanide metals may be used as nanothermometers operative over a wide range of temperatures
Nanolives technology was published in Nature Photonics in 2013("Marker-free phase nanoscopy), "and has the potential to enable completely new fields of research,
Beerotor is equipped with a mere 24 photodiodes (or pixels) distributed at the top and the bottom of its eye.
have been published in Nature Photonics("Deep in vivo photoacoustic imaging of mammalian tissues using a tyrosinase-based genetic reporter").
The photoacoustic imager contains a red laser, which shines pulses of light into the animal.
as blood cells absorb most laser light. The UCL scientists have engineered genetically tumour cells so they create tyrosinase,
This turns the cells dark brown so they absorb light from the laser and can be detected by the photoacoustic device.
and whispering galleries are found in applications ranging from sensing, spectroscopy and communications to the generation of laser frequency combs.
and presented this device in Nature Photonics("All-plasmonic Machzehnder modulator enabling optical high-speed communication at the microscale").
#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
and atmosphere molecules, resulting in new optical properties in graphene. The potential of the altered optical properties (like spectral transmission) of functionalized graphene are just starting to be recognized,
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
#Integration of quantum dots and photonic crystals produce brighter, more efficient light Recently, quantum dots (QDS) ano-sized semiconductor particles that produce bright, sharp,
and photonic crystal technology, could lead to brighter and more efficient mobile phone, tablet, and computer displays, as well as enhanced LED lighting.
They then used electrohydrodynamic jet (e-jet) printing technology to precisely print the QD-embedded polymers onto photonic crystal structures.
These photonic crystals limit the direction that the QD-generated light is emitted meaning they produce polarized light,
an ECE graduate student and the lead author of the research reported this week in Applied Physics Letters("Polarized quantum dot emission in electrohydrodynamic jet printed photonic crystals),
"their replica molded photonic crystals could someday lead to brighter, less expensive, and more efficient displays. ince screens consume large amounts of energy in devices like laptops, phones,
See explained. f you put the photonic crystal-enhanced quantum dot into a device like a phone or computer,
See fabricated a novel 1mm device (aka Robot Man) made of yellow photonic crystal-enhanced QDS.
"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,
because the world's leading quantum photonics group teamed up with Nippon Telegraph and Telephone (NTT), the world's leading telecommunications company.
Professor Jeremy O'brien, Director of the Centre for Quantum Photonics at Bristol University, explained:""Over the last decade, we have established an ecosystem for photonic quantum technologies,
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,
Alivisatos and Ralph Nuzzo of the University of Illinois are the corresponding authors of a paper in ACS Photonics describing this research entitled Quantum dot Luminescent Concentrator Cavity Exhibiting 30-fold Concentration.
In their ACS Photonics paper, the collaborators express confidence that future LSC devices will achieve even higher concentration ratios through improvements to the luminescence quantum yield, waveguide geometry,
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,
The researchers present their development in the journal Nature Photonics. Light determines the future of information and communication technology:
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.
The research is published in leading scientific journal, Nature Photonics("On-chip integratable all-photonic nonvolatile multilevel memory".
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.
The ultrathin lens enables potential applications in on-chip nanophotonics and improves the conversion process of solar cells.
noninvasive 3d biomedical imaging photonic chips aerospace photonics micromachines laser tweezing the process of using lasers to trap tiny particles.
The rapid development in nano-optics and on-chip photonic systems has increased the demand for ultrathin flat lenses with three-dimensional subwavelength focusing capability the ability to see details of an object smaller than 200 nanometres.
Recent breakthroughs in nanophotonics have led to the development of a number of ultrathin flat lens concepts,
research leader in nanophotonics at Swinburne Centre for Microphotonics (CMP), Associate professor Baohua Jia, said. The researchers produced a film that is 300 times thinner than a sheet of paper by converting graphene oxide film to reduced graphene oxide through a photoreduction process. hese flexible graphene oxide lenses are mechanically robust
Phd candidate Xiaorui Zheng said. hey have the potential to revolutionise the next-generation integrated optical systems by making miniaturised and fully flexible photonics devices.
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.
#Nanoscale photodetector shows promise to improve the capacity of photonic circuits Photonic circuits, which use light to transmit signals,
The scientists developed a nanoscale photodetector that uses the common material molybdenum disulfide to detect optical plasmons--travelling oscillations of electrons below the diffraction limit
rather than solely to the laser's wavelength, demonstrating that the plasmons effectively nudged the electrons in Mos2 into a different energy state."
if this type of device would be able to be used as a photodetector, "Goodfellow said.
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.
For instance, Bartell and colleagues will be looking at using tricks from nanophotonics, such as fabricating gold antennae to excite thermal excitations confined to nanoscale dimensions o
#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.
"In this structure--unlike other photodetectors--light absorption in an ultrathin silicon layer can be much more efficient
graduate student Jayer Fernandes and recent graduate Aditi Kanhere--are exploring ways to integrate the lenses into existing optical detectors and directly incorporate silicon electronic components into the lenses themselves s
graduate student Jayer Fernandes and recent graduate Aditi Kanhere--are exploring ways to integrate the lenses into existing optical detectors and directly incorporate silicon electronic components into the lenses themselves s
#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.
The research was supported financially by the Technology Foundation STW and recently published in Optics Express.
The work is described in the latest issue of Nature Photonics. While optical fibers have long been used for the transmission of data with light, inside a computer
The Nature Photonics paper states, y using optical near-field effects, we realize bit storage of up to eight levels in a single device that readily switches between intermediate states.
and is described in the journal Nature Photonics. The metamaterial consists of low-aspect-ratio silicon pillar arrays embedded in a polymer matrix and clad by gold films.
and can efficiently couple to photonic integrated circuits and other optical elements. ight doesn typically like to be squeezed
RI=zero The Nature Photonics paper explains what happens when a material refractive index is reduced to zero:"
#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
In a paper published in the latest issue of Nature Photonics the IMEC and University of Ghent team describes the development as the irst highly scalable monolithic solutionto a longstanding problem:
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.
That would in turn enable a radical scaling of a data center capacity, while simultaneously reducing increasingly colossal power demands with higher-efficiency data transfer.
but by implementing new technologies like silicon photonics this total could be cut by at least 10 per cent.
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
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