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"Time Telescope" Could Boost Fibre-Optic Communications
An anonymous reader writes "A time lens can focus a chunk of time to a point, rather like a normal lens focuses light rays. Put two time lenses together and you can create what a Cornell University team calls a 'time domain telescope' which can magnify time. They sent a 2.5 nanosecond long light pulse, encoding 24 bits of information, into their time telescope. What came out on the other side was the same 24 bit pulse, but compressed into 92 picoseconds. Squashing more information into a light pulse could help to send more information via optical fibres."
I'm used to these physics guys doing all kinds of crazy things with invisibility cloaks and such so I took the title to be a literal time lense.
After RTFA, the "time lense" is a frequency up-shifter. Still impressive, but not supernatural as I had hoped.
This is a complete oversell on a normal everyday phenomenon. This is a simple compression of a lightpulse, and has been done for a long time. Dispersion usually smears out a pulse, but can easily, compress the pulse. There is no "bending of time" here. Look up "Chirped pulse amplification" and also "Prism compressor", and maybe "soliton". First descibed in 1834 by John Scott Russell
don't cut it off www.mgmbill.org
Imagine a speech audio signal.
If you were to just compress the signal in time, the rate of speech would increase, but the frequency (pitch) would as well - it would sound like a chipmunk. This is what a simple resampling program would do.
On the other hand if you were to just frequency-shift the signal (say by heterodyning) then the rate of speech would be the same, but the pitch would change. This is what pitch-correction programs do.
If you do both in series and in opposite directions so the cancel, then the pitch remains the same but rate of speech is now increased. This is what fast playback programs (say for audio books) do.
The researchers figured out how to do the last to light using simple lenses. This could be useful because you can send the data down the same channel (like a frequency multiplexed fiber) as the original signal was intended for.