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MeirG
Well, we now need optical connectors to optically couple signals on a plugin ...
junjunwu168
If the waveguide is not isolated it is probably in touch with the polyimide ...
Photonic PCBs inching closer
2/5/2013 2:01 AM EST
PORTLAND,
Ore.--A team of researchers from IBM and Dow Corning Electronics is claiming a
breakthrough that could enable silicone to supplant copper for creating
fast, energy efficient photonic interconnects on printed-circuit boards
(PCBs). The team demonstrated optical waveguides using a photonic
polymer at the Photonics West 2013 conference Monday (Feb. 4).
IBM claims its collaboration with Dow Corning provides an integrated approach to optical interconnects, similar to how metal PCB traces route electrical signals around inside computers today. The polymer waveguides are "highly flexible and resistant to high temperatures," said Bert-Jan Offrein, manager of the Photonics Research Group at IBM Research (Zurich). Offrein said no curling or deformation was incurred for bends as tights a 1 millimeter, and for extreme operating conditions of 85 percent humidity and 185 degrees Fahrenheit.
Silicone makes uses of the same basic element as CMOS chips--silicon--but in a flexible form that can transmit light around the bends and turns with very little distortion. As a result, extremely fast and energy efficient photonic interconnects can be fabricated that are capable of carrying the exabytes of data needed for future data centers and supercomputers.
Eric Peeters, a vice president at Dow Corning Electronic Solutions, predicted that the new material will enable "silicone-based board-level interconnects that quickly supersede conventional electronic signal distribution methods."

Flexible photonic waveguide made from Dow-Corning silicone material in IBM's Binnig and Roher Nanotechnology Center (Rueschlikon, Switzerland).
The silicone polymer starts as liquid, like other optical materials such as glass, but can be dispensed under normal atmospheric conditions, solidifying in less than 45 minutes. The material also showed excellent adhesion to conventional PCB materials like polyimide, had losses as little as .03 dB per centimeter, was stable for over 2,000 hours at high temperature/humidity, and survived 500 thermal cycles between -40 and 248 degrees Fahrenheit.
The Photonics West presentation, "Stable and Easily Processable Optical Silicones for Low-Loss Polymer Waveguide" was presented by Brandon Swatowski, an application engineer at Dow Corning Electronics Solutions. Photonics West is taking place this week in San Francisco.
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IBM claims its collaboration with Dow Corning provides an integrated approach to optical interconnects, similar to how metal PCB traces route electrical signals around inside computers today. The polymer waveguides are "highly flexible and resistant to high temperatures," said Bert-Jan Offrein, manager of the Photonics Research Group at IBM Research (Zurich). Offrein said no curling or deformation was incurred for bends as tights a 1 millimeter, and for extreme operating conditions of 85 percent humidity and 185 degrees Fahrenheit.
Silicone makes uses of the same basic element as CMOS chips--silicon--but in a flexible form that can transmit light around the bends and turns with very little distortion. As a result, extremely fast and energy efficient photonic interconnects can be fabricated that are capable of carrying the exabytes of data needed for future data centers and supercomputers.
Eric Peeters, a vice president at Dow Corning Electronic Solutions, predicted that the new material will enable "silicone-based board-level interconnects that quickly supersede conventional electronic signal distribution methods."

Flexible photonic waveguide made from Dow-Corning silicone material in IBM's Binnig and Roher Nanotechnology Center (Rueschlikon, Switzerland).
The silicone polymer starts as liquid, like other optical materials such as glass, but can be dispensed under normal atmospheric conditions, solidifying in less than 45 minutes. The material also showed excellent adhesion to conventional PCB materials like polyimide, had losses as little as .03 dB per centimeter, was stable for over 2,000 hours at high temperature/humidity, and survived 500 thermal cycles between -40 and 248 degrees Fahrenheit.
The Photonics West presentation, "Stable and Easily Processable Optical Silicones for Low-Loss Polymer Waveguide" was presented by Brandon Swatowski, an application engineer at Dow Corning Electronics Solutions. Photonics West is taking place this week in San Francisco.
Related stories:
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resistion
2/5/2013 3:22 AM EST
Any optics person would know bends in waveguides cause light loss as total internal reflection is no longer satisfied.
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IBMZRL
2/5/2013 8:07 AM EST
With waveguides, loss-less bends can be made in case the index contrast is large enough compared to the bending radius of the bend. In the optical ray model, the total internal reflection condition is then still satisfied.
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resistion
2/5/2013 9:27 AM EST
If the index difference is that large, you have to worry about coupling loss from reflection at the waveguide end.
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junjunwu168
2/6/2013 8:54 PM EST
If the waveguide is not isolated it is probably in touch with the polyimide FPCB. PI has higher RI than silicone. So to form a lossless waveguide during bending in smaller diameter you will need a low RI cladding to the silicone. Fluoropolymer is probably the only choice for silicone. Am I missing something?
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jeremybirch
2/5/2013 10:07 AM EST
1) silicone is a analogue of carbon based polymers - but the chain is of silicon atoms not carbon ones. There are many different silicones.
2) do they deposit the silicone in tracks or are they coating a whole board then etching it? I don't think 45 minute drying time is very practical if you have to deposit it as tracks, but as a board coating it might just work
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iniewski
2/5/2013 3:01 PM EST
Cool technology...would anyone be interested in presenting it at emerging technologies symposium in Grenoble in 2014? www.cmosetr.com, kris.iniewski@gmail.com
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MeirG
2/7/2013 7:19 AM EST
Well, we now need optical connectors to optically couple signals on a plugin board to its motherboard...
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