148 research outputs found
The Glauber-Sudarshan and Kirkwood-Rihaczec functions
It is shown how to write the Kirkwood-Rihaczec quasiprobability distribution
as an expectation value of the vacuum state. We do this, by writing the
position eigenstates as a "displacment" of the vacumm. We also give a relation
between the Glauber-Sudarshan and Kirkwood-Rihaczec quasiprobability
distributions
Optical Production of the Husimi Function of Two Gaussian Functions
The intensity distribution of the Husimi function (HF) and the squared
modulus of the Wigner function (WF) are detected in the phase space of an
astigmatic optical processor. These results, obtained in the laboratory, are
compared against numerical results generated by using analytical calculation
for the HF and WF. The signal function is the superposition of two Gaussian
functions with a separation between them, having the same amplitude but a
different variance
Quantum derivation of Manley Rowe type relations
The Ermakov Lewis quantum invariant for the time dependent harmonic
oscillator is expressed in terms of number and phase operators. The
identification of these variables is made in accordance with the correspondence
principle and the amplitude and phase representation of the classical
orthogonal functions invariant. The relationship between the number and phase
operators is established through this invariant as the system evolves from one
frequency to another. In the specific case where the excitations represent the
photon number, these relations are equivalent to the power density transport
equations derived in nonlinear optical processes.Comment: 10 pages, no figure
Optical simulation of Majorana physics
We show a procedure to classically simulate the Majorana equation in 1+1
dimensions via two one-dimensional photonic crystals. We use a decomposition of
the Majorana equation into two Dirac equations and propose a novel approach
that uses a bi-chromatic refractive index distribution and nearest neighbor
couplings of the type found in Glauber-Fock lattices. This allows us to escape
the restriction of staying near the Brillouin zone imposed by the classical
simulation of Dirac dynamics with bi-chromatic lattices. Furthermore, it is
possible to simulate the evolution of Gaussian wavepackets under the
Majorana/Dirac equation with light impinging only into the first waveguide of
our bi-chromatic-Glauber-Fock lattice.Comment: 10 pages, 2 figure
Optical Bistability in a cavity with one moving mirror
We analyze the behaviour of a coherent field driving a single mode optical
cavity with one perfectly reflecting moving mirror and a partially reflecting
fixed mirror, and show that this system's output exhibits optical bistability
due to radiation pressure acting over the moving mirror.Comment: 6 pages, 1 figur
An optical analog of quantum optomechanics
We present a two-dimensional array of nearest-neighbor coupled waveguides
that is the optical analog of a quantum optomechanical system. We show that the
quantum model predicts the appearance of effective column isolation,
diagonal-coupling and other non-trivial couplings in the two-dimensional
photonic lattice under a standard approximation from ion-trap cavity
electrodynamics. We provide an approximate impulse function for the case of
effective column isolation and compare it with exact numerical propagation in
the photonic lattice.Comment: 10 pages, 4 figure
On the quantum phase problem
We present a phase formalism that passes the Barnett-Pegg acid test, i.e.
phase fluctuations for a number state are the expected value which
are the fluctuations for a classical random phase distribution. The formalism
is shown to have consistency subjected to different approaches.Comment: 5 pages, no figure
NOON states in cavities
We show how NOON states may be generated entangling two cavities by passing
atoms through them. The atoms interact with each cavity via two-photon resonant
transitions. We take advantage of the fact that depending on the state the atom
enter (excite or ground), it leaves or takes two photons per interaction and
leaves the cavities in a pure state
Normal and anti-normal ordered expressions for annihilation and creation operators
We give the normal and anti-normal order expressions of the number operator
to the power by using the commutation relation between the annihilation and
creation operators. We use those expressions to give general formulae for
functions of the number operator in normal and anti-normal order
Photon transport in binary photonic lattices
We present a review on the mathematical methods used to theoretically study
classical propagation and quantum transport in arrays of coupled photonic
waveguides. We focus on analysing two types of binary photonic lattices where
self-energies or couplings are alternated. For didactic reasons, we split the
analysis in classical propagation and quantum transport but all methods can be
implemented, mutatis mutandis, in any given case. On the classical side, we use
coupled mode theory and present an operator approach to Floquet-Bloch theory in
order to study the propagation of a classical electromagnetic field in two
particular infinite binary lattices. On the quantum side, we study the
transport of photons in equivalent finite and infinite binary lattices by
couple mode theory and linear algebra methods involving orthogonal polynomials.
Curiously the dynamics of finite size binary lattices can be expressed as roots
and functions of Fibonacci polynomials.Comment: 13 pages, 4 figure
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