1. Home
  2. Electronics Design
  3. OT? Noiseless Single-photon Amplification Demonstrated

OT? Noiseless Single-photon Amplification Demonstrated

Some regulars here seem to think that physicists never ome up with anything practical:

formatting link

"Research physicists have demonstrated the first device capable of amplifying the information in a single particle of light without adding noise.

"The research collaboration, involving Griffith University, The University of Queensland and University of Science and Technology of China, was able to amplify the noisy quantum state of a single photon subjected to loss, without adding noise in the process; in fact, their amplification reduced the noise in the quantum state."

There's a lot of "fancy stuff" involving quantum teleportation and so on, and it's touted as being applicable to quantum encryption, but I'm sure some bright boy (or girl) will figure out how to apply the principle to ordinary photonics and maybe prosaic optics like microscopes.

Mark L. Fergerson

Reply to
alien8752
Loading thread data ...

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

Reply to
Mr Stonebeach

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

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 USA 
+1 845 480 2058 

hobbs at electrooptical dot net 
http://electrooptical.net
Reply to
Phil Hobbs

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

--
Les Cargill
Reply to
Les Cargill

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.

Reply to
George Herold

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 -

Reply to
George Herold

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.

Reply to
Jan Panteltje

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.