TY  - JOUR
A1  - Breitenbach, Gerd
A1  - Illuminati, Fabrizio
A1  - Schiller, Stephan
A1  - Mlynek, Jürgen
T1  - Broadband detection of squeezed vacuum : a spectrum of quantum states
N2  - We demonstrate the simultaneous quantum state reconstruction of the spectral modes of the light field emitted by a continuous wave degenerate optical parametric amplifier. The scheme is based on broadband measurement of the quantum fluctuations of the electric field quadratures and subsequent Fourier decomposition into spectral intervals. Applying the standard reconstruction algorithms to each bandwidth-limited quantum trajectory, a "spectrum" of density matrices and Wigner functions is obtained. The recorded states show a smooth transition from the squeezed vacuum to a vacuum state. In the time domain we evaluated the first order correlation function of the squeezed output field, showing good agreement with theory.
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Felbinger, Timo
A1  - Schiller, Stephan
A1  - Mlynek, Jürgen
T1  - Oscillation and generation of nonclassical states in three-photon down conversion
N2  - The process of 3-photon down conversion 3 omega -> omega + omega + omega in an optical cavity is analyzed theoretically. A classical feature of this system is a first-order transition of the fundamental mode above a threshold 3omega pump power. We calculate the quantum properties of the steady state both using quantum trajectory simulations, and by perturbation expansion of the density operator. A nongaussian Wigner function exhibiting a threefold symmetry is found. Above threshold the Wigner function displays separate peaks among which tunneling occurs.
Y1  - 1998
ER  -