Abstract:
Phase properties of a classical signal can be improved by amplification,
approach that is problematic in its application on quantum states of
light, mostly because amplification also introduces additional noise.
However, there is a way around this problem. The amplification can work if
reduced probability of success is accepted. There are several possible
approaches to amplification, most of them relying on fine control of the
light field at the single photon level. But noiseless amplification can be
also achieved by substituting the expensive single photon resources with
noise. And this will be the story of that rather counter-intuitive
result...