Optical buffer on a silicon
By exploiting state of the art semiconductor manufacturing technology, scientists have created an optical buffer memory on a miniature silicon chip. The device – a kind of temporary storage area for light signals that works by slowing them down – is described in the January issue of Nature Photonics. Once optimized, it could help future optical networks to synchronize different data streams without needing to convert the signals into the electronic domain.The optical buffer is made by connecting together a string of up to 100 tiny silicon ring waveguides – tiny oval racetracks with a perimeter of just 55 micrometres. By experimenting with various designs, Yurii Vlasov and colleagues have shown that it is possible to create a buffer with a total footprint of less than 0.1mm squared that is able store up to 10 bits of information at data-rates of up to 20Gbit per second.Although silicon ring waveguides have been reported before, Vlasov’s team is the first to show that it is possible to make a device from such a large number of rings, and to test its compatibility with real data at gigabit speeds. Although further work is needed to reduce the losses and increase the delay/storage time of the buffer, the work is an important demonstration of the future potential of nanophotonics.
Author contact:Yurii Vlasov (IBM Thomas J Watson Research Center, Yorktown Heights, NY, USA)Tel: +1 914 945 2028; E-mail: yvlasov@us.ibm.com