A high-performance ‘photonic transistor’ that switches light signals instead of electronic signals could revolutionize optical signal processing
Electronic transistors, which act as miniature switches for controlling the flow of electrical current, underpin modern-day microelectronics and computers. State-of-the-art microprocessor chips contain several billion transistors that switch signals flowing in electrical wires and interconnects. With increasing data-processing speeds and shrinking chip sizes, however, wires and interconnects waste considerable energy as heat.
One alternative is to replace electrical interconnects with energy-efficient optical interconnects that carry data using light signals. However, a practical analogue of the transistor for optical interconnects does not yet exist. Hence, Vivek Krishnamurthy from the A*STAR Data Storage Institute and co-workers in Singapore and the United States are developing a practical ‘photonic transistor’ for optical interconnects that can control light signals in a similar manner to electronic transistors.
The researchers’ latest photonic transistor design is based on prevalent semiconductor technology and offers attractive attributes of high switching gain, low switching power and high operating speed.
Importantly, the research team’s design enables a switching gain of greater or equal to 2, which means the output signal is more than double the strength of the input signal. Hence, the transistor can be cascaded: the output signal from one photonic transistor is sufficiently strong so that it can be split to feed several others. Known as ‘fan-out’, this functionality means the design can become a building block to be scaled up to form larger circuits with many such switching elements connected together for all-optical processing on an optical interconnect platform for data- and telecommunications. Furthermore, Krishnamurthy says that the design consumes 10–20 times less power than the conventional all-optical switching technologies and can operate at very fast speeds.
The team’s design consists of a circuit of coupled silicon waveguides that guide infrared light with a wavelength of 1.5 micrometers. Some of the waveguides feature an optically active material, such as an indium gallium arsenide semiconductor, that can amplify or absorb signal light depending on whether or not it is optically excited. During operation, the intensity of a short-wavelength routing beam is used to control the strength of an output beam by altering the amount of absorption and gain in the circuit.
The researchers are now working to experimentally realize their optical transistor. “We are realizing it on a silicon chip so that it will be compatible with current microelectronic industry standards to enable commercial deployment,” explains Krishnamurthy. “Once we experimentally verify the prototype, we could further integrate it into large-scale optical switching systems for optical interconnects.”
The A*STAR-affiliated researchers contributing to this research are from the Data Storage Institute
Krishnamurthy. V., Chen. Y. & Ho S.-T. Photonic transistor design principles for switching gain >=2. Journal of Lightwave Technology 31, 2086–2098 (2013).
Donuts, math, and superdense teleportation of quantum information
29.05.2015 | University of Illinois College of Engineering
Physicists precisely measure interaction between atoms and carbon surfaces
29.05.2015 | University of Washington
Many joining and cutting processes are possible only with lasers. New technologies make it possible to manufacture metal components with hollow structures that are significantly lighter and yet just as stable as solid components. In addition, lasers can be used to combine various lightweight construction materials and steels with each other. The Fraunhofer Institute for Laser Technology ILT in Aachen is presenting a range of such solutions at the LASER World of Photonics trade fair from June 22 to 25, 2015 in Munich, Germany, (Hall A3, Stand 121).
Lightweight construction materials are popular: aluminum is used in the bodywork of cars, for example, and aircraft fuselages already consist in large part of...
Using ultrashort laser pulses, scientists in Max Planck Institute of Quantum Optics have demonstrated the emission of extreme ultraviolet radiation from thin dielectric films and have investigated the underlying mechanisms.
In 1961, only shortly after the invention of the first laser, scientists exposed silicon dioxide crystals (also known as quartz) to an intense ruby laser to...
The only professorship in Germany to date, one master's programme, one laboratory with worldwide unique equipment and the corresponding research results: The University of Würzburg is leading in the field of biofabrication.
Paul Dalton is presently the only professor of biofabrication in Germany. About a year ago, the Australian researcher relocated to the Würzburg department for...
Physicists have developed an innovative method that could enable the efficient use of nanocomponents in electronic circuits. To achieve this, they have developed a layout in which a nanocomponent is connected to two electrical conductors, which uncouple the electrical signal in a highly efficient manner. The scientists at the Department of Physics and the Swiss Nanoscience Institute at the University of Basel have published their results in the scientific journal “Nature Communications” together with their colleagues from ETH Zurich.
Electronic components are becoming smaller and smaller. Components measuring just a few nanometers – the size of around ten atoms – are already being produced...
Development and implementation of an advanced automobile parking navigation platform for parking services
To fulfill the requirements of the industry, PolyU researchers developed the Advanced Automobile Parking Navigation Platform, which includes smart devices,...
20.05.2015 | Event News
18.05.2015 | Event News
12.05.2015 | Event News
29.05.2015 | Life Sciences
29.05.2015 | Earth Sciences
29.05.2015 | Physics and Astronomy