2,230 research outputs found
Q-complements on log surfaces
In this paper the log surfaces without \QQ-complement are classified. In
particular, they are non-rational always. This result takes off the restriction
in the theory of complements and allows one to apply it in the most wide class
of log surfaces.Comment: Latex2e, 3 page
Photon noise in a random laser amplifier with fluctuating properties
We study fluctuations of the number of photocounts measured by an ideal
photodetector illuminated by light scattered in an amplifying disordered
medium, below the threshold for random lasing. We show that the variance of
fluctuations and their correlation function carry information about fluctuating
properties of the medium. A direct link is established between the fluctuations
of the number of photocounts due to the amplified spontaneous emission (ASE)
and the dimensionless conductance g of the medium. Our results suggest a
possibility of probing amplifying disordered media by analyzing statistics of
their ASE, without illuminating them from outside by a probe beam.Comment: 14 pages, 9 figure
Gaussian modeling and Schmidt modes of SPDS biphoton states
A double-Gaussian model and the Schmidt modes are found for the biphoton wave
function characterizing spontaneous parametric down-conversion with the
degenerate collinear phase-matching of the type I and with a pulsed pump. The
obtained results are valid for all durations of the pump pulses, short, long
and intermediately long
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