#SPACE: "NASA Webb Spinoffs Benefit Private Sector"

NASA's Webb telescope will not be launched un 2018, but already spinoff technologies are benefiting the materials, medical and aerospace industries. The high precision needed to cast and measure the accuracy of its gigantic mirrors and ultra-sensitive detectors are already being commercially deployed long before the telescope becomes operational. R. Colin Johnson

Artist conception of the James Webb Space Telescope. Credit: NASA

Here is what NASA says about Webb Telescope spinoffs: Much of the technology for the Webb had to be conceived, designed and built specifically to enable it to see farther back in time. As with many NASA technological advances, some of the innovations are being used to benefit humankind in many other industries.

The Webb telescope is the world's next-generation space observatory and successor to the Hubble Space Telescope. The most powerful space telescope ever built, the Webb telescope will provide images of the first galaxies ever formed, and explore planets around distant stars. It is a joint project of NASA, the European Space Agency and the Canadian Space Agency.

New technologies developed for NASA's James Webb Space Telescope have already been adapted and applied to commercial applications in various industries including optics, aerospace, astronomy, medical and materials. Some of these technologies can be explored for use and licensed through NASA's Office of the Chief Technologist at NASA's Goddard Space Flight Center, Greenbelt, Md.

Optics Industry: Telescopes, Cameras and More
The optics industry has been the beneficiary of a new stitching technique that is an improved method for measuring large aspheres. An asphere is a lens whose surface profiles are not portions of a sphere or cylinder. In photography, a lens assembly that includes an aspheric element is often called an aspherical lens. Stitching is a method of combining several measurements of a surface into a single measurement by digitally combining the data as though it has been "stitched" together.

Because NASA depends on the fabrication and testing of large, high-quality aspheric (nonspherical) optics for applications like the James Webb Space Telescope, it sought an improved method for measuring large aspheres. Through Small Business Innovation Research (SBIR) awards from NASA's Goddard Space Flight Center, QED Technologies, of Rochester, New York, upgraded and enhanced its stitching technology for aspheres. QED developed the SSI-A, which earned the company an "R&D 100" award, and also developed a breakthrough machine tool called the aspheric stitching interferometer. The equipment is applied to advanced optics in telescopes, microscopes, cameras, medical scopes, binoculars, and photolithography.

Aerospace and Astronomy:
In the aerospace and astronomy industries, the Webb program gave 4D Technology its first commercial contract to develop the PhaseCam Interferometer system, which measures the quality of the Webb telescope's mirror segments in a cryogenic vacuum environment. This is a new way of using interferometers in the aerospace sector.

An interferometer is a device that separates a beam of light into two beams, usually by means of reflection, and then brings the beams together to produce interference, which is used to measure wavelength, index of refraction, and also distances.

Interferometry involves the collection of electromagnetic radiation using two or more collectors separated by some distance to produce a sharper image than each telescope could achieve separately.

The PhaseCam interferometer verified that the surfaces of the Webb telescope's mirror segments were as close to perfect as possible, and that they will remain that way in the cold vacuum of space. To test the Webb mirror segments, they were placed in a "cryovac" environment, where air is removed by a vacuum pump and temperatures are dropped to the extreme cold of deep space that the space craft will experience. A new dynamic interferometric technique with very short exposures that are not smeared by vibration was necessary to perform these measurements to the accuracy required, particularly in the high-vibration environment caused by the vacuum chamber's pumps.

The interferometer resulting from this NASA partnership can be used to evaluate future mirrors that need to be tested in vacuum chambers where vibration is a problem.

Medical Industry: Eye Health
New "wavefront" optical measurement devices and techniques were created for making the Webb telescope mirrors. Those have led to spinoffs in the medical industry where precise measurements are critical in eye health, for example.

The technology came about to accurately measure the James Webb Space Telescope primary mirror segments during manufacturing. Scientists at AMO WaveFront Sciences, LLC of Albuquerque, N.M. developed a new "wavefront" measurement device called a Scanning Shack Hartmann Sensor.

The optical measuring technology developed for the Webb, called "wavefront sensing" has been applied to the measurement of the human eye and allowed for significant improvements. "The Webb telescope program has enabled a number of improvements in measurement of human eyes, diagnosis of ocular diseases and potentially improved surgery," said Dan Neal, Director of Research and Development Abbott Medical Optics Inc. in Albuquerque, N.M. The Webb improvements have enabled eye doctors to get much more detailed information about the shape and "topography" of the eye in seconds rather than hours.

Materials Industry: Measuring Strength
Webb technologies have opened the door to better measurement in testing the strength of composite materials. Measuring strain in composite materials is the same as measuring how much they change in certain environments. Measuring step heights allows one to understand very small changes in a surface profile and doing all of this at high speed allows the device to work even in the presence of vibration that would normally blur the results.

Webb telescope technologies have also been beneficial to the economy. The technologies have enabled private sector companies such as 4D to generate significant revenue and create high-skill jobs. Much of 4D's growth from a two man start-up to over 35 people can be traced to projects originally developed for the telescope. 4D has also been able to adapt these technologies for a wide range of applications within the astronomy, aerospace, semiconductor and medical industries.

In the future, other industries may benefit from other Webb telescope technologies.
Further Reading

Intel Spreading High-Speed Fiber Optics Everywhere

Fiber optics carries the high-speed signals moving data across the nation and around the world, but soon will be expanding its reach to every aspect of communications between computers, between chips on boards and even around the house. Look for fiber optics communications everywhere by the end of the decade. RColinJohnson @NextGenLog



Here is what Smarter Technologies says about silicon photonics: Intel promises to revolutionize communications everywhere from data centers to home networks with a cheap fiber-optic technology that casts photonic devices into cheap silicon chips. Within five years, Intel promises to obsolete copper wires for most communications applications...Today, most communications are carried by copper wires, even though fiber optics are smaller, lighter, faster and higher-speed. The problem is that converting electronic signals to and from optical signals is expensive, since converters require expensive photonic devices using exotic materials like indium gallium arsenide. Now Intel claims to have found a way to create photonic devices that compute with light using the cheap, plentiful silicon techniques it uses to create normal processor chips. Within five years, Intel promises to obsolete copper wires for most communications applications...
Full Text: http://bit.ly/NextGenLog-bcEM

"OPTICS: Silicon fiber optics debut"

Fiber optics for communications have vastly more bandwidth than standards networks, but cannot be manipulated as easily as electrical signals. By inserting crystalline silicon into the core of conventional optical fibers, Clemson University researchers hope to harness the embedded semiconductors to process optical signals. Applications could include multiplying frequencies and providing access to longer wavelengths not currently available when using conventional glass fibers.
Text: http://www.eetimes.com/showArticle.jhtml?articleID=211800117
Audio: http://i.cmpnet.com/eetimes/audio/slideshow/56/1.mp3

#MATERIALS: "Seeing Is Believing When Cloaks Disappear"

The world's first visible-light cloak recently converted nonbelievers by making a tiny object disappear—Harry Potter style. Transformational optics will enable a future where what you see is not always what is really there, according to the Karlsruhe Institute of Technology, which recently pulled off the first disappearance act to cloak a normal visible object.


The internal structure of the carpet cloak arrays pillars at the spacing of a photonic crystal which matches the wavelength of light to be cloaked, thereby bending it around hidden objects. Credit: KIT

Invisibility cloaks have been shown for infrared or microwave wavelengths, and Northwestern and Oklahoma State universities showed the world's first terahertz (which lies between infrared and microwave) cloaking at a recent conference. KIT, however, claims to have brought the magic of transformational optics to the normal visible-light spectrum.

By sculpting a "woodpile" of parallel pillars into a layered polymer that acts as a photonic crystal, the resulting "carpet cloak" shields objects illuminated with normal, unpolarized, red light—albeit only in an area half the size of a human hair. By making the spacings of the pillars the same as the light being transmitted through it, the material can bend light in almost any direction. Transformation optics works by continuously adjusting this spacing to guide light around objects, enabling invisibility cloaks.

The cloak works by adjusting the local phase velocity of light with the pillars’ spacing, but the beauty of the process is that it can be accomplished with direct-write lasers. The process works by first laying down a pattern of nanoscale-spaced pillars by etching a single layer of polymer. Then a filler is spread into the etched-out areas, a new layer of polymer is laid down, and the process repeats. After the material has been built up to whatever size is needed for the cloaked area, the filler is dissolved leaving just the woodpile of light-bending pillars. Even though the cloak only worked for red light (700-nanometer wavelength), KIT nevertheless claimed it was the first demonstration for normal unpolarized visible light.

KIT's lead researcher, Joachim Fischer, explained at CLEO that the key to achieving the nanoscale spacings necessary to cloak visible light was adapting diffraction-unlimited microscopy techniques to the laser direct-writing process. Those adjustments allowed the researchers to dramatically increase their etching resolution to the nanometer scale, thus achieving a visible light cloak where others were at longer wavelengths of infrared (micrometer), terahertz (millimeter) or microwaves (centimeter).

Next, KIT is aiming to half the spacing between its pillars again, to shrink their size enough that the carpet cloak will work at all visible wavelengths—not just red—finally realizing the Harry Potter dream. The researchers are also looking for ways to increase the area concealed.

Besides invisibility cloaks, the researchers believe their technique will enable flat, aberration-free lenses that can be integrated onto future optical microchips. Fischer's team is also working on what KIT calls optical "black holes" that could improve the efficiency of solar cells by letting them harvest a broader swath of wavelengths than today's solar cells, which must be tuned to a region's typical spectrum.
Further Reading: http://bit.ly/NextGenLog-mgyc

Europe Focuses Fiber #Optics on #Silicon #Photonics

Silicon-on-insulator (SOI) process technology enables silicon photonic components capable of terabit per second speeds on broadband core networks.

The European Union is aiming to lower the cost of fiber-optic communications by developing inexpensive silicon chips that turn photonics into a mass market. Look for fiber optic communications to start taking over from copper wires not only in data centers but in consumer electronics over the next seven years. RColinJohnson @NextGenLog


Silicon photonics sculpts out optical waveguides on standard CMOS chips, here a filter for optical fibers.

Here is what Smarter Technology says about fiber optics: Today, fiber-optic communications are ultra-high-speed, but also ultra-high-cost compared to conventional copper wires. But by recasting photonics onto silicon chips, instead of the exotic indium-gallium-arsenide compounds used today, a mass market for fiber optics will result. The European Union is planning to play a leadership role. The European Silicon Photonics Cluster is a multiyear, $36 million effort that aims not only to develop the technology but to raise awareness of silicon photonics and its potential applications in optical communications, optical interconnects between semiconductor chips and circuit boards, optical signal processing, optical sensing and biological efforts.
The Cluster is divided into 10 project "consortia," in which most of the leading European research institutes, universities and companies are participating...
Full Text: http://bit.ly/NextGenLog-93a6

#OPTICS: "Plastic optics boosted to 25 Gbit/s"

A new vertical-cavity surface-emitting laser (VCSEL) technology from VI Systems aims to extend the reach of cheap plastic fiber optics, with scientists at Georgia Institute of Technology reporting successful operation at 25 Gbits per second. VI Systems (Berlin) reports that it has achieved 40 Gbit/s in the lab and is aiming for 100 Gbit/s performance.
Further Reading

"MATERIALS: "Invisibility cloaks spread out"

Invisibility cloaks, made famous by Harry Potter but now possible in the lab, promise to hide our submarines from sonar, our missiles from radar and maybe someday even our soldiers wearing Potter-like capes. Despite the obvious hype, the scientific feasibility of invisibility cloaks as spawned a new field of science called transformation optics, which seeks to harness exotic metamaterials, nanophotonics and plasmonics to build super lenses for powerful microscopes.


Transfomation optics were used recently to develop an improved invisibility cloak with a 100-fold increase in area compared to previous visible-wavelength cloaks. The new design from Purdue University uses a relatively inexpensive glass and gold waveguide that achieved a more economical design using transformation optics. An inexpensive waveguide directs light around cloaked objects (center) so that even a laser bends around it to emerge on the other side with no shadow cast. Other invisibility cloaks use optical diffraction gratings that tune into specific wavelengths with a negative index of refraction that allows the cloak to provide invisibility, but only at those wavelengths. The Purdue device was formed from two gold-coated surfaces, one a curved lens, the other a flat sheet. The result was a broadband cloak, working at a wide swath of wavelengths simultaneously, enabling it to shield an area covering the entire spectrum of visible light. The demonstration showed how a laser benda around the cloaked area, leaving no shadow, even though the area was 100 times larger than the wavelength of the laser.
Text: http://www.eetimes.com/showArticle.jhtml?articleID=217600639

"OPTICS: IBM claims to best venerable LED"

IBM Corp. unveiled the world's first unipolar electroluminescent nanotube transistor and claimed it glows over 1,000 times brighter with as much as 10,000 times more photon flux than a light-emitting diodes (LEDs). By emitting thousands of photons in silicon with the same energy expenditure as one photon in gallium arsenide, IBM predicted that carbon nanotube transistors will lead to integrated optics on silicon chips. According to IBM, integrated optics on silicon chips could lower costs, accelerate electronics and mitigate the need for exotic semiconductors like gallium arsenide. IBM said its technique achieves 1000-fold brighter emissions by electrically stimulating a carbon nanotube suspended over a doped silicon wafer. The resulting excitons are electrically neutral, yet emit infrared light when recombined. Other research groups have reported light emission by carbon nanotubes stimulated to photoluminescence with a laser. IBM claims its technique uses only electrical stimulation to create an exciton density that is 100-fold larger than photoluminescence in nanotubes. IBM claimed it achieved very high efficiency with its light-emitting technique, IBM through the extreme confinement within a 2-nm-diameter carbon nanotube suspended from each end over a silicon back gate. IBM fabricated the light-emitting transistor by etching trenches in a silicon dioxide film on a highly doped silicon wafer. The wafer substrate acted as a back gate to the carbon nanotube transistor.
Text: http://www.eetimes.com/showArticle.jhtml?articleID=174300788

"SPACE: 3 more exoplanets photographed"

An observatory in Hawaii has harnessed adaptive optics to produce visible light photographs of the first three-planet solar system. The three gas giants, larger than Saturn and Jupiter, are orbiting the star HR8799, 130 lights years from Earth in the constellation Pegasus. Last week, NASA released photographs of a single planet 25 light-years away in the the Southern Fish constellation. The photos were taken by the 2.4-meter Hubble Space Telescope. The much larger telescopes at the Keck Observatory on Maui used adaptive optics techniques to render photographs rivaling those made by Hubble. The technique canceled out the distorting effects of the atmosphere. The resulting photographs of the three gas giant exoplanets (planets outside our solar system) were made by a team of Canadian, U.S. and British astronomers.
Text: http://www.eetimes.com/showArticle.jhtml?articleID=212100278
Audio: http://homepage.mac.com/guitarmedia/interviews/rcj3Planets.mp3

"OPTICS: IBM Preps Optics to Replace Copper Interconnects"

Recently perfected optical interconnection technologies will accelerate multi-core microprocessors to 100-GHz--20-times faster than today--plus will lighten mobile devices to about half their current weight, by obsoleting the heavy copper wire used for routing electronic signals around on printed circuit boards (PCBs) and even between cores inside microchips. Look for all-optical electronic devices within five years. R.C.J.


Optical fibers already carry the fastest communications signals over the Internet and between servers and supercomputers at high-performance data centers. By encoding electronic communications in the language of light, the higher frequencies and wider bandwidth of optical signals not only increases performance, but obsoletes heavy, bulky copper-based interconnects in favor of small, lightweight optical fibers. Each year, IBM announces a few more elements in its nanophotonic toolkit, including on-chip silicon-laser resonators, modulators, waveguides and switches. Plus, it has demonstrated a complete chip-to-chip optical bus. Now IBM claims it has crafted the final tool in its nanophotonics kit -- a tiny germanium optical receiver called an avalanche photodetector -- that will enable it to realize the dream of integrated CMOS optical interconnects.


The new 40G bps photodetector can be integrated on the edge of processors to receive optical signals sent between chips instead of using copper traces on printed circuit boards. And eventually, it will be integrated on the top layer of the microprocessor itself to facilitate lightning-fast communications between cores on the same chip, thus eliminating the need for copper wires inside and outside future electronic devices. By eliminating the copper traces on printed circuit boards and the copper wires inside the chips themselves, a major reduction can be made in the weight of mobile devices today.
Full Text: http://bit.ly/ay1ut7

"OPTICS: Gaza tunnels detected with fiber optics"

Detecting tunneling activity under the security fence separating Gaza from Egypt could be accomplished through a buried fiber-optic cable, according to researchers at the Technion-Israel Institute of Technology (Haifa, Israel). By combining a neural network with Brillouin optical time-domain reflectometry, small tunnels can be sensed by the buried optical fibers, researchers claimed.
Text: http://www.eetimes.com/showArticle.jhtml?articleID=212800121
Audio: http://homepage.mac.com/guitarmedia/interviews/rcjTunnel.mp3

#Silicon #Photonics uses Vapor-filled Waveguide

Scanning electron microscopic (SEM) image of hollow on-chip silicon waveguide produced by the Applied Optics Group at University of California at Santa Cruz.

The world's first demonstration of electromagnetic optical switching on a fully self-contained silicon chip heralds a day when fiber optics will carry information between chips. Look for novel optical solutions for everything from disk-server-farms to home networking over the next five years. RColinJohnson @NextGenLog


UCSC fabricates arrays of waveguides on a single four inch silicon wafer, here showing 32 atomic spectroscopy chips using them.

Here is what EETimes says about silicon photonics: A new technique harnesses vapor-filled optical waveguides on silicon chips to process data streams encoded on light, allowing optical signals to be slowed down and switched on-chip. This technique sidesteps the current requirement to convert optical signals to electrical signals in applications that detect, buffer, multiplex and store photonic information...In what is claimed to be the world's first demonstration of electromagnetic optical switching on a fully self-contained silicon chip, the technique employs quantum interference effects in an on-chip hollow-core optical waveguide filled with rubidium vapor. A control laser is used to switch the optical signal on and off as well as to slow the data stream's speed by up to 1,200 times...
Full Text: http://bit.ly/NextGenLog-atQs

"OPTICS: Microscope-on a-chip debuts"

Today's bulky, expensive microscopes could be come smaller and cheaper after researchers found a way to combine pinhole optics, microfluidics and a charge-coupled device (CCD) to assemble a working microscope on a single chip. Small enough to fit in a mobile phone or similar handheld device, the optofluidic microscope developed by California Institute of Technology engineers requires only sunlight for illumination, and could be mass-produced for $10. Caltech hopes to work with a manufacturing partner to produce handheld versions for remote monitoring. Applications could include malaria screening or identifying pathogens on the battlefield.
Text: http://www.eetimes.com/showArticle.jhtml?articleID=209900012

#OPTICS: "World's First Nanoscale Optical Fibers'

Photonic chips that compute with light instead of electricity--the holy grail of optics--will enable a faster, more sustainable Internet, by virtue of lowering its power consumption with the world's smallest optical fibers.



Researchers have created nanowires generated by direct laser writing, here stacked to form a three-dimensional woodpile photonic crystal with a pronounced stop gap.

At its current rate of growth, the Internet is on track to consume half the world's energy in the next decade, according to professor Min Gu, the Director of the Centre for Micro-Photonics at Swinburne University of Technology. To head off the debacle, Gu's research group has created the world's smallest optical fibers, which he claims will enable not only a faster, but a more sustainable Internet, by virtue of reduced energy consumption.
"The Internet has become a major energy consumer," said Gu. "In the next decade the Internet will account for half of the world’s energy usage--so making it more efficient will make a huge difference to our carbon footprint."

Researchers have created nanowires generated by direct laser writing, here stacked to form a three-dimensional woodpile photonic crystal with a pronounced stop gap.
His research team, which was recently ranked among the top 100 universities for physics research in the Academic Ranking of World Universities published annually by the Shanghai Ranking Consultancy, is working with the six university, Australian government funded, effort to stem Internet power consumption at the Centre for Ultrahigh bandwidth Devices for Optical Systems. The aim of CUDOS is to create an all-photonics Internet that drastically cuts energy consumption by computing with light instead of electricity.
Photonics encodes the binary ones and zeros of Internet communications on pulses of light instead of electronic charge packets. Electricity must overcome the resistance of the wires through which it travels, which causes them to heat up, wasting much of the energy required for communications signals. As a result, all long-haul Internet communications today are performed with optical fibers which carry signals between metropolitan areas faster and without all the heat.
However, once the signals reach their target city, they are translated into electrical signals with expensive, power hungry converters which receive the weightless photons of light from the long-haul fibers and translate them into electrical signals that travel down a cable- or digital-subscriber link (DSL) to the user's computer. Likewise, between distant metropolitan areas "repeaters" must periodically translate the optical signals into electrical ones, then use high powered lasers to re-encode the electrical signals as light pulses that continue down fibers to the next repeater.
The holy grail of photonics is to eliminate the need for repeaters, cable, DSL and even the wires between the chips inside your computer with nanoscale optical fibers that perform all computing with light, eliminating the need to ever translate weightless, energy conserving photons into heavy, energy wasting electrons. With optical fibers small enough, even the communications signals on the processor inside your computer could be made optical, saving energy for computers, routers, and other communications equipment as well as extending the battery life of the mobile device themselves.
In its most recent step toward realizing the dream of all-optical computing, doctoral candidate Elisa Nicoletti working on a CUDOS project in Gu's lab, created the world's smallest optical fibers. Measuring just 68 nanometers in diameter, the new optical fibers are small enough to be used inside all-optical routers, switches and other future photonic microchips. Measuring just one-twelfth the wavelength of the light being transmitted through them, the nanofibers were directly written with a laser onto microchips using a nonlinear material called a chalcogenide.
Other groups have created nano wires out of plastic, which is a passive material that merely passes the signal. But by using chalcogenide, Gu's group was able to demonstrate nanowires constructed into a three-dimensional "woodpile" photonic crystal with a pronounced stop gap. Such structures can work with laser-powered light pumps to perform all the functions performed today with power-hungry electrical routers and switches.
Further Reading

"OPTICS: IBM demos graphene optical link"

Silicon photonics is the holy grail of optical communications, enabling cheap integrated optics that handle all high-speed communications among chips and even among on-chip cores. Now IBM has demonstrated the last piece of the photonics toolkit--an optical receiver on a silicon-on-insulator substrate (SoI). Look for optical chips that integrate graphene with CMOS in five years. R.C.J.


IBM Research has demonstrated an optical link using a graphene photodetector fabricated on a silicon-on-insulator (SOI) substrate. The 10 Gbit per second receiver uses a novel interdigitated source and drain on a field-effect transistor (FET) with graphene as the channel. The vertical-incidence metal-graphene-metal photodetector achieved a very wide bandwidth of 300 nanometers to 6 microns, making the graphene optical link a promising candidate not only for communications, but for remote sensing, environmental monitoring and surveillance.
Full Text: http://www.eetimes.com/showArticle.jhtml?articleID=224200681

Transistor-laser breaks Kirchhoff's Law, rewrites textbooks #Semiconductor #Laser #Microchip

Transistor-lasers could enable on-chip optics by providing both an electrical and an optical output, but the old-school textbooks will have to be rewritten to accomodate the new device. Look for transistor lasers in commercial chips within five years. R.C.J.


The EE inventors of the transistor-laser (TL) —a transistor with both optical and electrical outputs—claim it fits perfectly within the semiconductor migration path to integrated optics. Unfortunately, all the electronics textbooks will have to be rewritten to use TLs in circuits, inventors say, because the transistor-laser breaks the time-worn concept of conservation of charge—Kirchhoff's Law, which has to be rewritten to accommodate the transistor laser developed by Milton Feng and Nick Holonyak Jr. at the University of Illinois. The researchers have created an equivalent circuit to their quantum-well-based transistor-laser that accurately models the charging and discharging mechanisms in the transistor-laser's base, where lasing occurs. As a consequence, TL circuits can now be studied in computer simulations that analyze both frequency and time-domain performance. The researchers have verified their algorithm on a prototype transistor-laser cast in III-V materials. The emitting layer was composed of indium gallium arsenide quantum wells sandwiched inside a p-type base. An emitting cavity of 2.2 microns wide and 0.85 millimeter long emitted at 1.0 micron wavelength, had a threshold current of 40mA and enabled direct modulation of the laser at 3 GHz...
Full Text: http://bit.ly/NextGenLog-cgg7

RT Transistor-laser breaks Kirchhoff's Law, rewrites textbooks #Semiconductor #Laser #Microchip

Transistor-lasers could enable on-chip optics by providing both an electrical and an optical output, but the old-school textbooks will have to be rewritten to accomodate the new device. Look for transistor lasers in commercial chips within five years. R.C.J.


The EE inventors of the transistor-laser (TL) —a transistor with both optical and electrical outputs—claim it fits perfectly within the semiconductor migration path to integrated optics. Unfortunately, all the electronics textbooks will have to be rewritten to use TLs in circuits, inventors say, because the transistor-laser breaks the time-worn concept of conservation of charge—Kirchhoff's Law, which has to be rewritten to accommodate the transistor laser developed by Milton Feng and Nick Holonyak Jr. at the University of Illinois. The researchers have created an equivalent circuit to their quantum-well-based transistor-laser that accurately models the charging and discharging mechanisms in the transistor-laser's base, where lasing occurs. As a consequence, TL circuits can now be studied in computer simulations that analyze both frequency and time-domain performance. The researchers have verified their algorithm on a prototype transistor-laser cast in III-V materials. The emitting layer was composed of indium gallium arsenide quantum wells sandwiched inside a p-type base. An emitting cavity of 2.2 microns wide and 0.85 millimeter long emitted at 1.0 micron wavelength, had a threshold current of 40mA and enabled direct modulation of the laser at 3 GHz...
Full Text: http://bit.ly/NextGenLog-cgg7

"OPTICS: Organic-silicon hybrid aims at optics"

Polymer filled silicon waveguides promise to bring photonics for CMOS chips, boosting their speed to 100s of GHz. Look for silicon photonics to blossom over the next few years. R.C.J.


Electro-optic-polymer-filled silicon waveguides could propagate optical signals on CMOS chips at up to 100 GHz, according to GigOptix-Helix AG, a subsidiary of GigOptix Inc. The company Wednesday (March 10) announced a $500,000 contract to prove the concept for a European Union project called the Silicon-Organic Hybrid Fabrication Platform for Integrated Circuits (SOFI). The SOFI program is funding seven research teams from four countries for three years. Each SOFI research team will be focusing on fabricating photonic modulators using optical waveguides on CMOS chip
Full Text: http://bit.ly/a2J5Km

#MATERIALS: "Nanolasers grown on silicon"

Computing with light will only be possible when we can integrate lasers alongside traditional electronic circuitry on silicon chips, which these researchers claim to now know how to do. Look for integrated silicon optics within four years. R. Colin Johnson @NextGenLog


The high crystal quality of III-V nanoneedles grown on silicon are enabling development of practical silicon-based optoelectronics .

Here is what my EETimes story says about integrated silicon optics: Scientists have long been interested in integrating lasers onto silicon to enable on-chip communications using light instead of electrons, which would lead to faster communication and increased bandwidth. But, unfortunately, there is a lattice mismatch between silicon and the traditional III-V materials used to craft semiconductor lasers. Now, researchers at the University of California at Berkeley claim to have surmounted that obstacle by growing indium-gallium-arsenide nano-pillars vertically. The researchers claim their technique is adaptable to mass production of robust on-chip structures for optical interconnects, field emitters, nonlinear optical signal generation, sensors, solar cells, displays and nano-fluidics...
Full Text: http://bit.ly/NextGenLog-eCcz

RT Transistor-laser breaks Kirchhoff's Law, rewrites textbooks #Semiconductor #Laser #Microchip

Transistor-lasers could enable on-chip optics by providing both an electrical and an optical output, but the old-school textbooks will have to be rewritten to accomodate the new device. Look for transistor lasers in commercial chips within five years. R.C.J.


The EE inventors of the transistor-laser (TL) —a transistor with both optical and electrical outputs—claim it fits perfectly within the semiconductor migration path to integrated optics. Unfortunately, all the electronics textbooks will have to be rewritten to use TLs in circuits, inventors say, because the transistor-laser breaks the time-worn concept of conservation of charge—Kirchhoff's Law, which has to be rewritten to accommodate the transistor laser developed by Milton Feng and Nick Holonyak Jr. at the University of Illinois. The researchers have created an equivalent circuit to their quantum-well-based transistor-laser that accurately models the charging and discharging mechanisms in the transistor-laser's base, where lasing occurs. As a consequence, TL circuits can now be studied in computer simulations that analyze both frequency and time-domain performance. The researchers have verified their algorithm on a prototype transistor-laser cast in III-V materials. The emitting layer was composed of indium gallium arsenide quantum wells sandwiched inside a p-type base. An emitting cavity of 2.2 microns wide and 0.85 millimeter long emitted at 1.0 micron wavelength, had a threshold current of 40mA and enabled direct modulation of the laser at 3 GHz...
Full Text: http://bit.ly/NextGenLog-cgg7