Photonics Spectra: Basic Science This is the syndication feed for Photonics Spectra: Basic Science. https://www.photonics.com/Splash.aspx?Tag=Basic+Science Thu, 28 Mar 2024 05:08:58 GMT Wed, 16 Sep 2015 14:06:10 GMT 1800 Theory Describes 'Molecules' of Light
Theoretical work has shown how two photons can be bound together in much the same way that atoms form molecules.

If demonstrated experimentally, the phenomenon could be exploited to enhance photon detectors and enable quantum computing.

"Lots of modern technologies are based on light, from communication technology to high-definition imaging," said researcher Alexey Gorshkov. "Many of them would be greatly improved if we could engineer interactions between photons."

Two photons, depicted in this artist's rendering as waves at left and right, can be locked together at a short distance. Under certain conditions, the photons can form a state resembling a diatom, represented as the blue dumbbell shape at center. Courtesy of E....]]>
https://www.photonics.com/Articles/Theory_Describes_Molecules_of_Light/p5/a57734 A57734 Wed, 16 Sep 2015 14:06:10 GMT
Light-Sensitive Medium Drives Nanoparticle Assembly
Light has long been used to trigger self-assembly of nanoparticles. A novel approach may be able to achieve the same end more reliably by focusing light on the medium containing the nanoparticles instead of the nanoparticles themselves.

The new technique is based on how nanoparticles react when illumination changes the medium's acidity. It could prove useful in applications including drug delivery and reversible writing of information, according to researchers at the Weizmann Institute of Science.

Its advantage over other techniques is that the nanoparticles aren't required to have light-sensitive coatings, which can degrade over time.
Nanoparticles in a light-sensitive medium scatter in the light (top) and aggregate in the...]]>
https://www.photonics.com/Articles/Light-Sensitive_Medium_Drives_Nanoparticle/p5/a57726 A57726 Mon, 14 Sep 2015 13:26:08 GMT
Individual Photons Squeezed by QDs
Quantum dots (QDs) can provide the control necessary to "squeeze" individual photons — a feat previously considered impossible to observe.

Squeezing is quantum phenomenon that produces an extremely low-noise signal potentially useful in technology designed to pick up faint signals, such as the detection of gravitational waves, as well as in optical communications.

Laser light was used to excite individual quantum dots to create squeezed single photons in a quantum optics laboratory at the University of Cambridge. Courtesy of Mete Atature.
While other experiments have demonstrated the effect in light pulses, this was the first time it has been observed in single photons, according to researchers at St. John's College at...]]>
https://www.photonics.com/Articles/Individual_Photons_Squeezed_by_QDs/p5/a57676 A57676 Mon, 31 Aug 2015 12:46:19 GMT
Spin Hall Effect Called Fundamental Property of Light
The spin of incident light determines the direction of propagation of evanescent waves along a surface, according to researchers at the Riken Center for Emergent Matter Science.

The finding demonstrates that the quantum spin Hall effect, already well known in electrons, is also an intrinsic property of photons, the researchers said.

"On a purely scientific level, this research deepens our understanding of the classical theory of light waves, developed by James Clerk Maxwell 150 years ago, and it could also lead to applications using optical devices that are based on the direction of spin," said lead researcher Konstantin Bliokh.

Schematic of experiments demonstrating the quantum spin Hall effect of light. The incident...]]>
https://www.photonics.com/Articles/Spin_Hall_Effect_Called_Fundamental_Property_of/p5/a57528 A57528 Thu, 25 Jun 2015 14:00:00 GMT
Angular Acceleration Observed in Helical Light Beams
The orbital angular momentum of laser light traveling along a helical path through space can accelerate and decelerate as it spins into the distance.

This is the first time that angular acceleration has been observed in light, according to a team of researchers from Africa and Germany. The phenomenon could lead to new applications in structured light fields, they said.

By combining two structured light fields in the form of Bessel beams (a), the resulting beam (b) spins as it travels. The rate of spin can be controlled. Images courtesy of Andrew Forbes/Wits School of Physics.

Orbital angular momentum is altered by twisting a light beam's wavefront into a helical shape. Usually this twist is smooth, like a spiral staircase...]]>
https://www.photonics.com/Articles/Angular_Acceleration_Observed_in_Helical_Light/p5/a57367 A57367 Thu, 23 Apr 2015 11:06:25 GMT
Inorganic Compound Could Replace Laser Dyes
An inorganic compound may serve as a longer-lasting replacement for laser dyes in a variety of applications.

A team from the Spanish National Research Council (CSIC) and the Academy of Sciences of the Czech Republic, developed a laser whose medium is borane, a substance “based on boron hydrides, inorganic cluster compounds with a rich and diverse chemistry,” according to the study published in Nature Communications (doi: 10.1038/ncomms6958).

A laser solution. Images courtesy of Spanish National Research Council/Academy of Sciences of the Czech Republic.

Borane presents efficient and degradation-resistant laser emission in the blue spectral region, making it suitable for applications such as spectroscopy and...]]>
https://www.photonics.com/Articles/Inorganic_Compound_Could_Replace_Laser_Dyes/p5/a57080 A57080 Wed, 14 Jan 2015 00:00:00 GMT
Optical Surfaces to Supply Beam Reducers for European Research Center
Optical Surfaces Ltd. will provide six motorized beam reducers for the British Science & Technology Facilities Council’s Central Laser Facility.

The beam reducers will be used for CW alignment and “on shot” diagnostics, with a maximum of 1 percent transmission at 1053 and 527 nm and input energies up to 50 J. The on-shot mode requires a carefully designed “dump” to prevent the high energy beam from interacting with the transmitted output, which would result in high background noise and stray reflections.

The Vulcan laser facility's Target Area West. Courtesy of the Science & Technology Facilities Council.

Based on a Dall-Kircham off-axis mirror design, the beam reducers will have a...]]>
https://www.photonics.com/Articles/Optical_Surfaces_to_Supply_Beam_Reducers_for/p5/a56942 A56942 Mon, 01 Dec 2014 00:00:00 GMT
Coating Reflects Sunlight, Radiates Heat to Cool Buildings
A thin-film coating has the potential to cool buildings by simultaneously radiating heat from inside and reflecting sunlight.

The photonic radiative cooling material reflects incoming sunlight (the sun’s reflection seen on the panel) and sends heat from inside the structure directly into space as infrared radiation (reddish rays). The blue areas on the roof show the cooling effect. Courtesy of Nicolle R. Fuller/Sayo-Art LLC.
Developed by a team at Stanford University, the 1.8-µm-thick photonic radiative cooling film is made of seven layers of silicon dioxide and hafnium oxide on top of a thin layer of silver.

The coating is a highly efficient mirror, preventing 97 percent of sunlight from striking the building...]]>
https://www.photonics.com/Articles/Coating_Reflects_Sunlight_Radiates_Heat_to_Cool/p5/a56936 A56936 Wed, 26 Nov 2014 00:00:00 GMT
Breaking Ground Now: Next-Gen Giant Telescopes
A new generation of larger, faster and more far-reaching telescopes is poised to revolutionize our understanding of the universe.

The largest telescope on Earth is currently the Gran Telescopio Canarias in the Canary Islands of Spain, which was built in 2009 with an aperture of 10.4 m. This 10-m design will hold the record for another four to eight years, but a new crop of next-generation telescopes now under construction will make a technological leap in instrumentation and size – some to 30 and 40 m. And that will change everything.

Upon its scheduled completion in 2022, the Thirty Meter Telescope (TMT) will be one of the largest telescopes in the world. Conceived in 2003 by the Association of Canadian Universities for...]]>
https://www.photonics.com/Articles/Breaking_Ground_Now_Next-Gen_Giant_Telescopes/p5/a56858 A56858 Wed, 05 Nov 2014 00:00:00 GMT
Algae Carbon Flow Controlled by Changing Light Colors
Blue and red light-sensing photoreceptors can be used to control the carbon flow in diatoms, a major group of algae that generates about one-fourth of the Earth’s oxygen and perform around a quarter of global CO2 assimilation.

Researchers from Leipzig University and the Helmholtz Center for Environmental Research made the findings, which they said show that cultures pre-acclimated to blue light and red light exhibited similar growth performance, photosynthesis rates and metabolite profiles.

Optical micrograph of a diatom. Courtesy of Christian Wilhelm/Leipzig University.

“Diatoms display a special way of reacting to light and adapting their metabolism to the changing light conditions in the water,” said...]]>
https://www.photonics.com/Articles/Algae_Carbon_Flow_Controlled_by_Changing_Light/p5/a56827 A56827 Tue, 28 Oct 2014 00:00:00 GMT
Imaging Digs Deep to Improve Crops
Boosting the output of important food crops such as rice and maize to meet the needs of the world’s growing population requires improvements both above and below the soil. A new imaging technique could aid these efforts.

Developed by a team at the Georgia Institute of Technology and Penn State University, the new technique and accompanying software measures and analyzes plant root systems, essential to gathering water and nutrients. It “combines a field-imaging protocol and algorithmic approach to analyze mature root systems grown in the field,” the researchers wrote in the study.

Researchers are studying root systems of various food crops’ dried root systems. Among them are maize plants, shown here....]]>
https://www.photonics.com/Articles/Imaging_Digs_Deep_to_Improve_Crops/p5/a56763 A56763 Fri, 10 Oct 2014 00:00:00 GMT
Photons Act Like Liquid, Crystal in Experiment
A system for “crystallizing” photons could help answer fundamental questions about quantum physics.

In an effort to develop exotic materials such as room-temperature superconductors, a team from Princeton University locked together photons so that they became solidly fixed in place.

“Here we set up a situation where light effectively behaves like a particle in the sense that two photons can interact very strongly,” said professor Dr. Hakan Tureci. “In one mode of operation, light sloshes back and forth like a liquid; in the other, it freezes.”
Oscillations of photons create an image of frozen light. On the left, photons flow easily between two superconducting sites. The light was later...]]>
https://www.photonics.com/Articles/Photons_Act_Like_Liquid_Crystal_in_Experiment/p5/a56668 A56668 Wed, 10 Sep 2014 00:00:00 GMT
Imaging Shows Bubbles Could Make Energy-Efficient Nanoparticles
High-speed cameras and UV-sensitive materials are helping advance understanding of bubbles — which could mean big things for nanoparticles.

In fact, a system in which bubbles mix liquids is an energy-efficient route toward producing nanoparticles. A team from Princeton University has demonstrated that some of the tiny particles that are hurled when a bubble pops can actually be pushed down into the water when that water is covered with oil.

Previously, such particles, which are produced by bursting bubbles’ aerosol droplets, have typically only been known to launch outward. The results of the new study offer new insight into the mixture of nonsoluble liquids, the researchers said.

The researchers send bubbles...]]>
https://www.photonics.com/Articles/Imaging_Shows_Bubbles_Could_Make_Energy-Efficient/p5/a56591 A56591 Wed, 20 Aug 2014 00:00:00 GMT
Atwater and Polman Receive the Julius Springer Prize
Atwater and Polman have pioneered the use of metallic nanostructures that support optical resonances called surface plasmons, to control light at the nanoscale. They have demonstrated how light can be more efficiently absorbed and trapped in solar cells by integrating nanostructures in the solar cell, enabling the fabrication of ultrathin solar cells.

Harry Atwater is the Applied Physics and Materials Science professor at the California Institute of Technology and named the plasmonics field in 2001. He is the director of the DOE Energy Frontier Research Center...]]>
https://www.photonics.com/Articles/Atwater_and_Polman_Receive_the_Julius_Springer/p5/a56560 A56560 Fri, 08 Aug 2014 00:00:00 GMT
NASA Engineer to Complete First 3-D-Printed Space Camera
New imaging instruments made using laser-based 3-D printing could bring the benefits of such technology to the forefront.

NASA aerospace engineer Jason Budinoff is developing a 350-mm dual-channel imaging telescope and a 50-mm camera whose outer tube, baffles and optical mounts are all printed as a single structure.

“This is a pathfinder. When we build telescopes for science instruments, it usually involves hundreds of pieces,” Budinoff said, noting that those components are complex and expensive to build. “But with 3-D printing, we can reduce the overall number of parts and make them with nearly arbitrary geometries.”

In particular, the 50-mm camera’s design features four different pieces...]]>
https://www.photonics.com/Articles/NASA_Engineer_to_Complete_First_br3-D-Printed/p5/a56559 A56559 Thu, 07 Aug 2014 00:00:00 GMT
Technique Could Simplify Photonic Crystal Formation
A new method could allow scientists to custom-grow defect-free photonic crystals.

A team from Princeton University and Columbia University created computer models demonstrating the technique, adding precisely sized chains of polymers to a colloidal suspension.

While the creation of solids via colloidal suspension is not a new idea, the researchers said this was the first time the technique has been shown to be viable for creating a crystal pure enough to split light for an optical circuit.

Colloids form the initial two layers of a crystal (left). When a third layer is added, the crystal forms one of two possible shapes (right). The vertical blue lines show a representative shape of the polymer when confined in the voids...]]>
https://www.photonics.com/Articles/Technique_Could_Simplify_Photonic_Crystal/p5/a56506 A56506 Fri, 25 Jul 2014 00:00:00 GMT
Image Processing Method Offers Enhanced Underwater Views
New image-enhancing software for cameras allows scientists to more easily observe details under water.

A team from the Netherlands Organization for Applied Scientific Research and the Royal Netherlands Navy used Nvidia Corp.’s CUDA (Compute Unified Device Architecture) graphics processing unit to develop new imaging software that uses algorithms based on imaging systems for compound security and unmanned aerial vehicles.

Reference video footage of a harbor bottom. The original image is at top, while at bottom the same image is shown after contrast enhancement. Courtesy of SPIE.

Traditional underwater cameras are typically hampered by low-contrast color changes, as well as interference due to camera noise and floating...]]>
https://www.photonics.com/Articles/Image_Processing_Method_Offers_Enhanced/p5/a56502 A56502 Thu, 24 Jul 2014 00:00:00 GMT
Solar Energy Researcher wins $10,000 Award
McCormick is a professor at Portland State University where her research is focused on developing photoreductive elimination catalysts for solar energy conversion and organic transformation. Her research aims to create photoactive catalysts to increase the rate of hydrogen production and provide a clean source of hydrogen as a carbon natural fuel.

With her award, McCormick plans to purchase the PTI QuantMaster 300, which measures steady state fluorescence and excited state lifetimes over many wavelengths and timescales.

For more information, visit...]]>
https://www.photonics.com/Articles/Solar_Energy_Researcher_wins_10000_Award/p5/a56484 A56484 Fri, 18 Jul 2014 00:00:00 GMT
Sensor Amplifies Molecule Signatures
A new spectroscopy technique can accurately identify the structure and composition of individual molecules.

Researchers from the Rice University Laboratory for Nanophotonics (LANP) developed the device, which they said has the ability to amplify single molecules’ optical signatures by about 100 billion times. It is designed to study individual molecules that contain fewer than 20 atoms.

“The ideal single-molecule sensor would be able to identify an unknown molecule — even a very small one — without any prior information about that molecule’s structure or composition,” said lead researcher and LANP Director Dr. Naomi Halas. “That’s not possible with current technology, but this new...]]>
https://www.photonics.com/Articles/Sensor_Amplifies_Molecule_Signatures/p5/a56473 A56473 Thu, 17 Jul 2014 00:00:00 GMT
Novel Photodetector Made from Zinc Nanostructure
A nanoporous structure is laying the groundwork for a new type of photodetector.

A team from the State Key Laboratory of Petroleum Resources and Prospecting at the China University of Petroleum has developed the new photodetector, made for application with an infrared pulsed laser.

"In the present work, we propose a type of infrared photodetector based on a nanoporous … structure, which is synthesized by a simple sol-gel method," they said in the study.

This chart shows the photoresponse of the nanoporous ZnO/ n-Si sample under the laser pulse illumination at varying energy levels. T1 and t2 represent the corresponding time of the transient voltage peaks. The inset shows the linear relationship between the time...]]>
https://www.photonics.com/Articles/Novel_Photodetector_Made_from_Zinc_Nanostructure/p5/a56419 A56419 Mon, 07 Jul 2014 00:00:00 GMT