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).
'Growing' active sites on quantum dots for robust H2 photogeneration
08.07.2020 | Chinese Academy of Sciences Headquarters
On-chip spin-Hall nanograting for simultaneously detecting phase and polarization singularities
08.07.2020 | Light Publishing Center, Changchun Institute of Optics, Fine Mechanics And Physics, Chinese Academy
Kiel physics team observed extremely fast electronic changes in real time in a special material class
In physics, they are currently the subject of intensive research; in electronics, they could enable completely new functions. So-called topological materials...
Solar cells based on perovskite compounds could soon make electricity generation from sunlight even more efficient and cheaper. The laboratory efficiency of these perovskite solar cells already exceeds that of the well-known silicon solar cells. An international team led by Stefan Weber from the Max Planck Institute for Polymer Research (MPI-P) in Mainz has found microscopic structures in perovskite crystals that can guide the charge transport in the solar cell. Clever alignment of these "electron highways" could make perovskite solar cells even more powerful.
Solar cells convert sunlight into electricity. During this process, the electrons of the material inside the cell absorb the energy of the light....
Empa researchers have succeeded in applying aerogels to microelectronics: Aerogels based on cellulose nanofibers can effectively shield electromagnetic radiation over a wide frequency range – and they are unrivalled in terms of weight.
Electric motors and electronic devices generate electromagnetic fields that sometimes have to be shielded in order not to affect neighboring electronic...
A promising operating mode for the plasma of a future power plant has been developed at the ASDEX Upgrade fusion device at Max Planck Institute for Plasma...
Live event – July 1, 2020 - 11:00 to 11:45 (CET)
"Automation in Aerospace Industry @ Fraunhofer IFAM"
The Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM l Stade is presenting its forward-looking R&D portfolio for the first time at...
07.07.2020 | Event News
02.07.2020 | Event News
19.05.2020 | Event News
08.07.2020 | Materials Sciences
08.07.2020 | Health and Medicine
08.07.2020 | Physics and Astronomy