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Luis Sanchez
I agree with you zeeglen in that the article’s title could be improved… I too ...
Dave.Dykstra
Another interesting development in photonics. Since this can be done with ...
Optical diode boosts silicon photonics efforts
R Colin Johnson
11/28/2011 9:49 AM EST
PORTLAND, Ore. -- A thin-film optical diode demonstrated recently at the Massachusetts Institute of Technology can be integrated onto a silicon photonic chip along with lasers and waveguides. Previously, a separate, discrete device was required.
Called a "diode for light" by its creator, MIT professor Caroline Ross, the device creates a one-way street for photons in the same way an electric diode directs a current flow in only one direction. Optical diodes will be useful for future photonic chips that would eliminate the need for translating optical into electrical signals and back again in order to perform switching and signal processing functions.
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| MIT engineering professor Caroline Ross has created the world's first silicon optical diode. |
Garnet, a material that is both transparent and magnetic, is more difficult than silicon to fabricate on CMOS chips. Nevertheless, Ross and colleagues demonstrated that thin-films of garnet could be deposited on silicon using standard processing steps.
Funding for the research was provided by the National Science Foundation.
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zeeglen
11/28/2011 1:49 PM EST
Interesting and kudos to the developers, but semantics could be a bit confusing. On reading the headline it sounded like a better laser/led/pin/avalanche device had been invented. These devices names indicate their function and they are all considered optical diodes.
Too bad the name 'diode' is already in use for photon sources and sinks that interact with moving electrons, as well as electron diodes that permit (in most uses) only one-way flow of electrons. They too have names that indicate function - zener, switching, rectifier, varactor, Schottky, tunnel, Gunn, etc; and they have a cathode and anode which is why they are called diodes.
Maybe these new devices could be named something like 'optical check valves' to distinguish their function. Or maybe a 'Ross turnstile'.
Whatever, this sounds like another significant milestone in the development of optical switching technology.
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Robotics Developer
11/28/2011 9:14 PM EST
I would call them light switches or maybe even traffic lights.. :}) If they could now turn the effect on/off that would be a really neat device..
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Dave.Dykstra
11/29/2011 1:03 AM EST
Another interesting development in photonics. Since this can be done with standard processing, it should be fairly straightforward to manufacture and should provide some new more cost effective designs in the not too distant future.
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Luis Sanchez
11/29/2011 1:15 PM EST
I agree with you zeeglen in that the article’s title could be improved… I too were mislead in to thinking of a diode that instead of Light Emitting, it sensed light. But can we settle for only a light rectifier diode? I think that actually keeps it simple and understandable.
Anyways, this indeed approaches one step closer to having the long pursued optical circuit.
Congratulations to the MIT professor.
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