Tiny gears on computer chips generate a vortex of light that could boost optical computing
For the first time, researchers have used tiny gears made of germanium to generate a vortex of twisted light that turns around its axis of travel much like a corkscrew. Because germanium is compatible with the silicon used to make computer chips, the new light source could be used to boost the amount of data that can be transmitted with chip-based optical computing and communication.
The researchers, from the University of Southampton in the U.K., and University of Tokyo, Toyohashi University of Technology and Hitachi Ltd., all in Japan, describe the new light-emitting gears in The Optical Society (OSA) journal Optics Express. With a radius of one micron or less, 250,000 of the gears could be packed into just one square millimeter of a computer chip.
There is a great deal of interest in generating light that is twisted, or has orbital angular momentum, because of its advantages for communications and computing. Today, light is used to carry information by varying the number of photons emitted or switching between light’s two polarization states. With twisted light, each twist can represent a different value or letter, allowing the encoding of a great deal more information using less light.
“Our new microgears hold the potential for a laser that can be integrated on a silicon substrate— the last component needed to create an integrated optical circuit on a computer,” said the paper’s first author Abdelrahman Al-Attili, from the University of Southampton. “These tiny optical-based circuits use twisted light to transmit large amounts of data.”
Using strain to improve light emission
It has been impossible to make a usable miniaturized light source on silicon, the material commonly used to make computer chips and associated components, because the material’s properties led to poor light-generating efficiency. Although germanium has similar limitations, applying strain by stretching it can improve its light emission efficiency.
“Previously, the strain that could be applied to germanium was not large enough to efficiently create light without degrading the material,” said Al-Attili. “Our new microgear design helps overcome this challenge.”
The new design features microgears that are freestanding at the edges so that they can be stretched by an oxide film deposited over the structures. This allows tensile strain to be applied without breaking the germanium’s crystal structure. The gears stand on a silicon pedestal that connects it to the top of the silicon substrate and allows heat to dissipate during operation.
To demonstrate their new design, the researchers used electron beam lithography to fabricate the very fine physical features that form the gears’ teeth. They then illuminated the gears with a standard green laser that did not emit twisted light. After the microgear absorbed the green light it generates its own photons that are circulated around the edges forming twisted light that is reflected vertically out of the gear by the periodic teeth.
Precision optical simulations
The researchers tested and tweaked their design using computer simulations that model the way light propagates in the gears over nanoseconds or even shorter time periods. By comparing the prototype’s light emission with computer simulation results, they were able to confirm that the gears generated twisted light.
“We can precisely design our device to control the number of rotations per propagation wavelength and the wavelength of the emitted light,” said Al-Attili.
The researchers are now working to further improve the efficiency of light emission from the germanium microgears. If successful, this technology would make it possible to integrate thousands of lasers onto a silicon chip for transmitting information.
“Silicon fabrication technologies that were developed to make electronic devices can now be applied to make various optical devices,” said Al-Attili. “Our microgears are just one example of how these capabilities can be used to make nano- and microscale devices.”
The Latest on: Optical computing
via Google News
The Latest on: Optical computing
- Optical imaging system visualizes molecular features of breast cancer tissue in real-time on December 21, 2018 at 7:39 am
A team of researchers from the University of Illinois at Urbana-Champaign has developed a portable optical imaging system that can visualize ... professor in electrical and computer engineering at the ... […]
- Demand for archival optical discs to take off in 2020, says Ritek chairman on December 20, 2018 at 10:50 pm
according to chairman and CEO Gordon Yeh for blank optical disc maker Ritek. While 70-80% of cloud computing data centers use magnetic tapes to store data currently, leading ones such as Facebook have ... […]
- Optical Disc Drives (ODDs) Market SWOT analysis & Technological Innovation by Leading Industry Players- Lenovo, Samsung, ASUS, Liteon, LG on December 20, 2018 at 3:32 pm
In computing, an optical disc drive (ODD) is a disc drive that uses laser light or electromagnetic waves within or near the visible light spectrum as part of the process of reading or writing data to ... […]
- New optical memory cell achieves record data-storage density on December 20, 2018 at 7:07 am
This is an important step toward an all-optical computer, a long-term goal of many research groups in this field. "Optical fibers bring light-encoded data to our homes and offices, but that ... […]
- Could AMOEBAS be the future of computing? on December 20, 2018 at 6:43 am
Researchers found they have unique computing abilities that could one day rival conventional ... as well as by processing optical feedback in parallel instead of serially. They are now developing an e... […]
- 3D Printing Optical Illusions at the Nanoscale on December 19, 2018 at 11:57 pm
He has done a lot of work with computer vision, and that work led him ... “A trompe l’oeil, referring to an art genre, is painted by using optical illusions,” Sugihara explains. […]
- Global Optical Disk Drives Market Report 2018 Companies included HLDS, PLDS, TSST, ASUSTeK, Pioneer, AOpen, BTC Behavior Tech Computer and Others on December 19, 2018 at 7:24 am
Report includes data about consumer perspective, comprehensive analysis, statistics, market share, company performances (Stocks), historical analysis 2012 to 2017, market forecast 2018 to 2025 in term... […]
- Portable optical system uses AI to better detect parasites on December 19, 2018 at 4:10 am
providing a throughput that is orders of magnitude better than traditional optical microscopy-based examination. The research, published in Nature Light: Science & Applications, was led by Aydogan Ozc... […]
- Next Big Personal Device: Computer, Smartphone, Or Nothing? on December 19, 2018 at 2:30 am
We should forget all the copper and build massive optical networks… which happened at some scale. Good job, prophets of the past, all these technologies are still working. But no, they were never the ... […]
- Bloody B975-Light Strike Optical Gaming Keyboard Review — Responsive and Satisfying on December 12, 2018 at 11:25 am
Bloody's B975 optical keyboard is one of my favorites strictly for gaming ... but it has also quickly become my default keyboard for pretty much all of my day-to-day computer uses. As a pure gaming ke... […]
via Bing News