We have proposed and experimentally tested a general definition for the nonclassicality of a quantum optical process based on its action on coherent light states.
Category: Quantum Optics
Aug 01 2012
Adaptively probing the shape of quantum light
We describe the first use of a genetic algorithm to adaptively probe the arbitrary spectral/temporal shape of ultrashort quantum light states. Besides fully reconstructing the complex spectral/temporal structure of a single photon, we also demonstrate how to use this capability as a clever new way of encoding quantum information.
Jan 01 2011
A hi-fi noiseless amplifier for quantum light states
We have demonstrated the operation of a non-deterministic noiseless amplifier based on the addition and subtraction of single photons. Our scheme greatly outperforms all other existing approaches to phase-insensitive noiseless amplification, both in terms of amplification gain and final state fidelity.
Oct 18 2009
First direct test of quantum commutation rules
Arbitrary superpositions of quantum operators demonstrated: first direct quantitative test of quantum commutation rules. We designed a scheme for conditionally generating arbitrary coherent superpositions of quantum operators. The general scheme was later applied to an experiment for implementing the commutator of the creation and annihilation operators. We quantitatively verified the well-known commutation rules in a …
Dec 18 2008
Playing with photon subtraction
We implemented a reliable scheme for single photon subtraction and tested its effects on paradigmatic light states: Fock, thermal, and coherent. When applied to coherent states, the annihilation operator does not modify the state itself. Experimentally verified that coherent states are eigenstates of the photon annihilation operator.
Sep 23 2008
Cavity-enhanced generation of highly-nonclassical states
We use a pulsed pump enhancement cavity to produce highly-nonclassical states of light at high repetition rates. The frequency comb structure of the pump laser may be transferred to the produced quantum light.
Aug 01 2008
To the roots of non-classicality: First reconstruction of a non-classical Glauber-Sudarshan P-function
We performed the first reconstruction of a non-classical P-function for a photon-added thermal light state. This is the first demonstration of non-classicality according to the original definition by R. Glauber.
Sep 23 2007
Direct experimental test of quantum non-commutativity by single photon creation and annihilation
We have implemented simple sequences of photon addition and subtraction to/from a light field. By verifying the difference in the final states when using the two operators in reverse order, we provide the first direct test of quantum commutation rules.
Oct 23 2006
Single-photon remote temporal delocalization and violation of a Bell’s type inequality
We have remotely delocalized a single photon onto two distinct and widely separated temporal modes. The tomographic analysis of the two-mode homodyne data has allowed us to prove (under some assumptions) the violation of a form of Bell’s inequality.
Oct 23 2004
First experimental photon addition
First realization of single-photon-added coherent states. We have generated and analyzed novel states of light that continuously change their character from fully quantum to fully classical.
