Nanostructures Give Infrared Photodetectors Three Colors to See In

The nanostructured materials known as Type-II indium arsenide/gallium antimonide/aluminum antimonide (InAs/GaSb/AlSb) superlattices have been around since the 1970s and have served in infrared detection applications since the late 1980s. Since then, Type-II Sb-based superlattice materials have evolved drastically with many variants suited for different applications.

Now researchers at Northwestern University, led by Manijeh Razeghi, have developed a new superlattice design, called M-structure superlattice. It can be used to make devices that operate as a shortwave/mid-wave/long-wave infrared photodetector. Shortwave infrared wave (SWIR) bands make it possible to detect reflected light. Mid-wave detection picks up hot plumes and long-wave infrared detects cooler objects. [Read More…]

Indium Tin Oxide Might Be the Material Photonics Has Been Waiting For

There are plenty of reasons why it’s useful to transfer information through photons or use light particles to carry out tasks within a system or device, speed chief among them. But in order to use photons with even greater dexterity in the future, researchers will need to control the way light behaves as it passes through a material.

Now a team led by Robert Boyd, a physicist at the University of Ottawa and the University of Rochester, has found that a transparent metal called indium tin oxide (ITO), which is often used in touchscreens and on airplane windows, can achieve a particularly high degree of optical nonlinearity—making it a good candidate for future photonics applications. [Read More…]

Nanotubes Serve as Light Emitter in Integrated Photonic Circuit

Using fiber optic cables as waveguides for transmitting light that is ultimately converted into voice calls or data has been a mainstay for the telecommunications industry for decades.

But it’s been a massive struggle to adapt this kind of technology to the scale of a microchip so that photons carry data through an integrated circuit instead of electrons. Now researchers at Karlsruhe Institute of Technology (KIT) in Germany have tackled a major problem in making integrated optical circuits a reality by creating nanoscale photonic emitters with tailored optical properties that can be easily integrated into a chip. [Read More…]

Graphene Filter Could Make Wireless Data Transmission 10 Times Faster

Researchers at Ecole Polytechnique Fédérale de Lausanne (EPFL) and the University of Geneva in Switzerland have developed a graphene filter for microchips that could potentially lead to wireless transmission rates 10 times as fast what chips deliver today.

In research described in the journal Nature Communications, the Swiss researchers actually fabricated what is known as a non-reciprocal isolator. The isolator filters backward radiation, preventing waves from being reflected back towards their source. [Read More…]

World’s Smallest Diode Is Made of DNA

Scientists have now created what they say is the world’s smallest diode, one the size of a single (rather short) molecule of a DNA. This work could help spur development of DNA components for molecular electronics, its creators claim. [Read More…]

Light Could Become the Dominant Form of Heat Transfer

Objects can transfer heat to their surroundings using light, but that method of heat exchange has always been thought to be very weak compared with conduction and convection. Now, in collaborative research among researchers at Columbia, Cornell, and Stanford, they discovered that we just weren’t doing it right. Their conclusion: light could become the most dominant form of heat exchange between objects.

In research described in the journal Nature Nanotechnology, the scientists discovered that when two objects are really close together, heat transfer via radiation is 100 times stronger than had been predicted. [Read More…]

Piezoelectric Graphene Ink Enables Thin-Film Pressure Sensors of Any Size

UK-based Haydale Graphene Industries Plc has established itself over the years as one of the go-to companies if you wanted graphene to have just the right properties for the device you were aiming to develop. If you wanted the graphene to have high conductivity, or maybe conductivity was not as critical as its thermal properties, Haydale was the place you would go to get graphene that did exactly what you wanted. [Read More…]

Graphene’s Role as a Superconductor Just Got Better

Graphene is an amazing conductor. The transport of electrons through graphene nanoribbons has even surpassed what scientists thought were the theoretical limits for the material—so much so that electrons moving through it seem to behave almost like photons. Graphene’s amazing properties as a conductor has inspired some researchers to explore whether the single-atom-thick sheets of carbon could also be made into superconductors. Last year, an international research team from Canada and Germany was able to demonstrate that graphene can be made to behave that way when it’s doped with lithium atoms. [Read More…]