Random-sampling
XUV Ramsey spectroscopy
(May 2011)
We demonstrate a new scheme for performing Ramsey-type
spectroscopy of XUV atomic transitions with high-order harmonics. Random
time-sampling intervals are used to achieve absolute XUV frequency measurements
at high accuracy and resolution.
A hi-fi
noiseless amplifier for quantum light states
(January 2011)
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.
Our PhD
student Constantina Polycarpou
wins the Best Poster Prize at the “Quantum Communication based on Integrated
Optics” Heraeus Seminar
(March 2010)
Ramsey XUV
spectroscopy on bound atomic states shows potential high resolution
(March 2010)
We demonstrate the potential of a Ramsey spectroscopic scheme
based on high-order harmonics to reach a resolving power >105 in
the XUV. This is done by measuring clear quantum interferences in the
excitation of an Argon transition at 87 nm for XUV pulse delays larger than 100
ps.
(Appeared in Optics Letters).
Our works on
single-photon manipulation of quantum light states have been chosen among the
OSA “Best of 2009” in Optics and Photonics News
Arbitrary
superpositions of quantum operators demonstrated: first direct quantitative
test of quantum commutation rules
(December 2008 - October 2009)
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 direct experiment for the first time.
Our Wigner
functions on the cover
of “The nature of light” CRC-Press book
Our work
selected among the “BEST OF 2008” in New Journal of Physics
Experimentally
verified that coherent states are eigenstates of the photon annihilation
operator
(December 2008)
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.
Toward quantum
frequency combs:
Cavity-enhanced generation of highly-nonclassical states
(September 2008)
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.
(Appeared in Physical Review A).
Valentina Parigi wins the prize for the best poster presentation at
the
Quantum &
Nonlinear Optics - Ph.D. Summer School
Backfallsbyn, Hven, DK
(August 2008)
To the roots
of non-classicality:
First reconstruction of a non-classical Glauber-Sudarshan
P-function
(August 2008)
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.
(Appeared in Physical Review A Rapid Communications.).
Simple
quasi-phase-matching in high-order harmonic generation
(July 2008)
We demonstrate a simple technique for enhancing harmonic
conversion yields by an array of gas interaction zones.
(Appeared in Physical Review A Rapid Communications).
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.
(See more in the
Quantum Optics section).
Link to Science paper: http://www.sciencemag.org/cgi/content/abstract/317/5846/1890
Link to Science comment paper by Boyd et al.: http://www.sciencemag.org/cgi/content/summary/sci;317/5846/1874
Link to Nature News paper: http://www.nature.com/news/2007/070924/full/070924-10.html
Direct
interferometric measurement of atomic dipole phases in high-order harmonic
generation
(July 2006)
We
have used an interferometric technique to directly measure the intrinsic
nonlinear phase related to the different electronic trajectories involved in
high-order harmonic generation in the XUV. (See more in the HHG section)
Single-photon
remote temporal delocalization and violation of a
(January-October 2006)
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. (See more in the Quantum Optics
section)
The 2005 Nobel Prize
in Physics was awarded to Theodor W. Haensch
(October 5th, 2005 )
Ted
Haensch and Marco Bellini performed one of the key
experiments leading to the invention of the femtosecond
frequency comb (and, later, to the Nobel prize) in Florence. (See more in the
section on the coherence properties of supercontinuum)
First realization of
single-photon-added coherent states
(October 22nd, 2004 )
We
have generated and analyzed novel states of light that continuously change
their character from fully quantum to fully classical. (See the Quantum Optics
section)
Link to Science paper: http://www.sciencemag.org/cgi/content/abstract/306/5696/660