Posts Tagged ‘wavelength’
September 13th, 2009 | 
Author: One of the ever-present trends in electronics is that stuff gets smaller. Although it doesn’t get much attention, the fact that electronic features can be scaled continuously in size down to something very close to the single atom level is an important reason why electronic devices are still king. The pretenders to the throne—optical devices—continue to sit off to one side while their supporters develop cunning plans for a takeover. All of those plans focus on making optical circuit elements smaller.
One of the main barriers to reducing the size of optical components is the wavelength of light. Visible light has a wavelength of around 500nm, so devices that manipulate light, like lenses and waveguides, must have comparable sizes. At least up until now—a long-awaited development has now provided a proof of principle, demonstrating that lasers can be made as small as 50nm, sizes that are comparable to current electronic features.
Normally, the absolute smallest length that laser hardware can have is a half wavelength, so the blue laser diode in your PS3 could be as short as 200nm (it’s not though; it’s considerably longer). Even worse, while the length may now be 200nm, the width and height have to be much bigger so that the end mirrors provide a good reflecting surface. These size issues have kept on-chip optics at something close to a stand-still for well over a decade.
In the last few years, scientists have begun to take fresh interest in the optical properties of metals. The way that light can cause the electrons in a metal oscillate coherently has led to new ideas for scaling down optical elements. These electron oscillations, called surface plasmon polaritons, have been shown to travel down wires just a few nanometers in diameter, providing the opportunity to scale things down.
These surface plasmon polaritons don’t last very long though. The electrons in the metal quickly dissipate their energy by bouncing off the atoms in the wire, heating them up, while the remaining energy is re-radiated as light. To overcome this, you need an amplifier, and, as an initial source of light, a laser. Such a laser, called a spacer (surface plasmon laser), has been proposed on several occasions, but until now, nobody had actually produced one.
To create the spaser, researchers took gold nanospheres and coated them with a sodium glass. On top of that, they placed an outer shell of dye-impregnated glass. The inner gold sphere acts as the resonator for the light. The light remains on the outside of the gold sphere as the electrons inside slosh back and forth—the light field extends far enough that it passes through the dye-impregnated outer shell, which provides gain.
The middle layer of sodium glass acts as a separator, preventing the dye molecules from interacting directly with the metal. Otherwise, the interaction would act to broaden the range of colors the dye molecule could emit and shorten the amount of time it spends in the excited state, where it can emit light.
The basic idea is that blue-green light is shone on the particles and absorbed by the dye. The excited dye molecules then begin to spontaneously emit green photons, some of which hit the chewy gold center, exciting a surface plasmon. The surface plasmon starts sloshing back and forth, and its field sweeps through the excited dye molecules, stimulating them to emit, adding to the surface plasmon. In the meantime, part of the energy stored in the surface plasmon radiates as coherent light.
The researchers observed that their spaser had all the characteristics expected of a laser: a threshold, narrow emission line, and relaxation oscillations. A threshold means that it requires a certain amount of input energy before a sufficient number of dye molecules contribute light to overcome the losses that occur as the electrons slosh about. Below this energy, a weak broad range of colors are emitted, while above, only a single color is emitted.
Finally, after the energy is dumped into the dye, it takes some time for the spaser to start going but, once going, it quickly produces short, intense pulses of light, called relaxation oscillations—typically, we prefer to operate lasers so that only a single pulse is emitted on these occasions, but we can’t always be choosy.
So, we now have 50nm laser hardware, which could conceivably be combined with nanowires to start developing optical circuits that really do look like electronic circuits (e.g., small and cheap). This laser was powered by a very powerful pump laser, meaning that it’s only small if you ignore the enormous power supply. But that was a side effect of how the experiment was put together. A single spaser used about 20 microwatts of power, so much smaller pump sources are feasible. If they can achieve continuous wave operation, the researchers are on to a winner.
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Article Source: Nano lasers offer hope for scalable optical processing
Its time to add some more color to your television by bringing home Mitsubishi Laser TV. This is an ultimate laser device in the optics and optical components industry. At the CES exhibition this year the company came out with its brand new innovation that is powered by a laser-based light engine which can provide the most extensive range colors, the most clarity, and the best depth of field. This is one of the most technologically advanced television in all manners and the company is claiming this 65-inch Laser High Definition Television to be the first of its kind in the industry.
Christened as LaserVue, this product takes pride in being most energy efficient large-format and the only high-definition television to be embellished with such features. This electronic equipment is not only popular for delivering two times of the color as compared to its competitors but also consumes less power when compared to a LCD or a Plasma TV. Besides some other features that makes this product go way ahead than its rival are 3D-ready viewing capabilities, full stereo range of sound capabilities, integrated speakers and 10-inch inches thin and design for floor stand as well as wall-mount applications.
LaserVue, is a first hand laser Television innovation that incorporates laser beams to create the magic on the screen. As laser beams have the capacity to be turned in whichever wavelength of light one wants, it is possible for the television to use ideal shades of red, green, and blue to produce a variety of colors. Mitsubishi, which is known for its significant technology innovations in many areas is trying to capture yet another major segment of the electrical and electronic industry through this HDTV. One of the main feature of the product is that it uses lasers to light and reflect the images out of the screen instead of a projector bulb or LEDs.
As per Frank DeMartin, the vice president of Mitsubishi, this laster technology is sure to create a platform for the intensely real and vivid world, that will be way ahead of the ordinary flat TV to become a television to give a true dimension experience.
This product is planned to be available for the general masses from the end of the year. The 50 inch model of this TV will be competing with 65-inch LCD TVs and is priced at $6,000 only. So what are you waiting for! Grab your own piece LsaseVue, a Hollywood entertainment experience and get a television that goes beyond flat to make you understand the actual meaning of ‘True Dimension’.
Having an experience of 9 years in the engineering and scientific industry, i have been working in this industry as an analyst and researcher. Besides, various other undertaking in the scientific and engineering markets to my credit,
Article Source: Laser TV – The Long Awaited Technology
When realizing the term data acquisition (DAC) it’s important to first know what is being acquisitioned: real world data. And real world data translates directly into the life sciences.
Life science, or biology, is a discipline of science that has, for hundreds of years, formed opinions of scientists, doctors, and thinkers alike. Theories and medications have been created with the study of life science, just as crimes have been solved, and organisms understood. The basic way living organisms interact with one another and their surroundings, how these organisms are structured, how they grow, what their origin may be, and their general evolution, is more or less what the term ‘life science’ encapsulates.
Real world data gets manipulated by a computer, where its signals and waveforms are processed, extracting critical information and storing it digitally in a computer processed machine. The data gets measured by components of data acquisition systems where sensors convert measurements and electrical signals before a computer manipulates the data and its signals and waveforms are processed. Critical information is then obtained and stored digitally in a computer processor, completing the first and second steps of the data acquisition process.
After life science has been converted to wavelength data, it is recorded by a data logger. Data logging is an electronic device that collects data over time, or in a specific radius, and is collected by one of three means, which include: built in instruments and sensors, or external instruments and sensors. After said data is collected, manipulated, and transformed, useful information is highlighted to suggest different types of scientific conclusions.
This process, seemingly lengthy, has allowed many growths in scientific understanding and continues on a number of levels to produce further understanding of organisms, and their relationship to the world at large.
For more information on data acquisition and data acquisition systems, please visit Biopac.com
Article Source: Data Acquisition
Blu-ray players will soon become a thing of the future with many people already becoming vastly interested in them and casting aside their DVD players. Blu-ray is basically a high definition alternative to DVD’s so you can watch films in crystal clear format and a higher resolution.
The first blu-ray disc titles were released back in June 2006 and are still gradually making their way into the limelight and the international market as only a selected amount of people understand what they are, the benefits of them, and of course the money to actually purchase one of these devices.
The disc itself is the same size and shape as a DVD disc, the only difference is blu-ray uses a blue laser to read and write, and this laser has a shorter wavelength from its beam than that of a DVD so the ability to store more on the disc is possible, DVD’s use a red laser to read and write with a longer beam length so storage potentials are limited.
At the moment the rewritable discs come in at anything from a dual layer disc that holds 25GB per layer, so 50GB altogether, and right through to Riteks latest development where they have successfully developed a 10 layer disc that reaches the boundaries of 250GB.
A lot of films that are currently being released are also being developed in the Blue-ray form which means you can watch these on a blu-ray player in HD, and surprisingly the prices of a blu-ray disc are very reasonable. For example, if you wanted to buy Batman: The Dark Knight you can be looking as cheap as 14.99 for the blu-ray format. That said, for a decent blu-ray player you can expect to pay anything from 150 – 300.
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Article Source: What Are Blu-Ray Players?