The maverick military mayhemware mavens of DARPA have once again sent ripples of sensation oscillating through the world of acronyms, as they ask the US tech community to build them an "iPhoD".
This is not, perhaps curiously, a fruitbite-branded music appliance and/or smartphone. The boffinry chiefs of DARPA may be eccentric, may often pay huge premiums for trendy and dubiously-capable stuff, but at least in this case they aren't looking to buy from Steve Jobs. Though they do seem to be trying to sprinkle a little bit of his pixie dust on themselves, at least by association.
"iPhoD" actually stands for "Integrated Photonic Delay", it says here. Quibblers might suggest that accepted Acronym Club rules would have led this to be dubbed IPD, or at most IPhoD; but DARPA, always full of zeitgeist zest, has insisted on the trendy small "i".
As for what an integrated photonic delay is, or why you want one, well. These are deep waters. In essence, the idea seems to be that it would be nice to handle photonic links on chips rather than in fibre devices, but at the same time retain certain desirable qualities of fibre machinery. In particular it would be nice to be able to delay photonic signals in an integrated on-chip waveguide the way one can using glass.
According to DARPA:
The ability to generate long optical delays with low intrinsic loss is useful for a wide range of high-precision military applications and systems including: high timebandwidth product analog optical signal processors and delay lines for wideband RF systems, optical buffers for all-optical routing networks, and ultra-stable optical interferometers for sensing applications, eg rotation sensors.
Various US military high-tech systems make use of optical networks, including the B-2 Stealth bomber. There are also aspirations at DARPA and other places to build photonic or partly-photonic computers, which might allow faster and better processing by smaller machines, overcoming the limitations of current electronics.
DARPA certainly hint that iPhoDs might be a key component of such future machinery.
If successful, iPhoD will enable unprecedented integrated optical delay performance and complexity, thereby furthering the technological precision of our military. The iPhoD program will build the framework of a scalable integrated photonic platform technology that provides for the handling and manipulation of photons with throughput efficiency and precision approaching that of electrons within electronic integrated circuits.
The full DARPA request can be read here (pdf), for those interested. ®