OT? Noiseless Single-photon Amplification Demonstrated

There is the theorem by Caves that phase-independent linear amplification always adds noise, and this has been traditionally circumvented by parametric amplification which is phase-dependent. But now this is something different. They claim non-deteministic noiseless amplification. I would have equated non-determinism with noise! Apparently they use something more shrewd. Interesting.

Regards, Mikko

Interesting, thanks.

Of course, strictly speaking an ordinary coherent detection system does much the same thing, if "noise" is understood as the ratio of the variance of the amplified signal to the original. The difference is that the one-photon signal has Poisson statistics (or some squeezed version) and the amplified one has Gaussian statistics. That just amounts to a redistribution of variance from the N=1 state to the N=0 state.

Cheers

Phil Hobbs

Does that then mean you can't put two of these in series for more "gain"?

First I didn't know that about parametric amps, so thanks.

In quantum things the amount of noise can depend on the coupling. (I'm thinking of this paper by Rolf Landauer on noise.)

Say does a maser add noise?

George H.

Apparently they use something more shrewd.

th

of

nd

state.

Ouch, Phil, you lost me on the last part. I got the Poisson/ Gaussian bit, (some averaging can turn Poisson to Gaussian, no?) But what's N?

George H.

t -

On a sunny day (Mon, 12 Nov 2012 13:29:33 -0800 (PST)) it happened " snipped-for-privacy@bid.nes" wrote in :

There exists no 'particles of light'. Nuf said. LOL :-) hehe Just made my day.