Simple Mod Turns Diodes Into Photon Counters

KentuckyFC writes "The standard way to detect single photons is to use an avalanche photodiode in which a single photon can trigger an avalanche of current. These devices have an important drawback, however. They cannot distinguish the arrival of a single photon from the simultaneous arrival of two or more. But a team of physicists in the UK has found a simple mod that turns avalanche photodiodes into photon counters. They say that in the first instants after the avalanche forms, its current is proportional to the number of photons that have struck. All you have to do is measure it at this early stage. That's like turning a Fiat 500 into a Ferrari. Photon counting is one of the enabling technologies behind optical quantum computing. A number of schemes are known in which it is necessary to count the arrival of 0, 1 or 2 photons at specific detectors (abstract). With such a cheap detector now available (as well as decent photon guns), we could see dramatic progress in this field in the coming months."

Comments

Down already?

[DrLudicrous]

Instantaneously slashdotted site?

Re:Ability to count 1,2,3 photons...

[fyngyrz]

You gotta love slashdot's moderation. Of course a post about how you might use the precise technology brought up by an article is off-topic. Of course it is.

This is why letting any idiot moderate is a bad idea. Inevitably, you get idiots moderating. :-) This is also why you have to read slashdot at -1; moderation as a filter is pathologically unfit for use by sensible readers.