23 research outputs found
Laguerre-Gaussian Modes and the Wigner Transform
Recent developments in laser physics have called renewed attention to
Laguerre-Gaussian (LG) beams of paraxial light. In this paper we consider the
corresponding LG modes for the two-dimensional harmonic oscillator, which
appear in the transversal plane at the laser beam's waist. We see how they
arise as Wigner transforms of Hermite-Gaussian modes, and we proceed to find a
closed form for their own Wigner transforms, providing an alternative to the
methods of Simon and Agarwal. Our main observation is that the Wigner transform
intertwines the creation and annihilation operators for the two classes of
modes.Comment: 12 pages, minor corrections; submitted, Journal of Modern Optic
Manipulation of Semiclassical Photon States
Gabriel F. Calvo and Antonio Picon defined a class of operators, for use in
quantum communication, that allows arbitrary manipulations of the three lowest
two-dimensional Hermite-Gaussian modes {|0,0>,|1,0>,|0,1>}. Our paper continues
the study of those operators, and our results fall into two categories. For
one, we show that the generators of the operators have infinite deficiency
indices, and we explicitly describe all self-adjoint realizations. And secondly
we investigate semiclassical approximations of the propagators. The basic
method is to start from a semiclassical Fourier integral operator ansatz and
then construct approximate solutions of the corresponding evolution equations.
In doing so, we give a complete description of the Hamilton flow, which in most
cases is given by elliptic functions. We find that the semiclassical
approximation behaves well when acting on sufficiently localized initial
conditions, for example, finite sums of semiclassical Hermite-Gaussian modes,
since near the origin the Hamilton trajectories trace out the bounded
components of elliptic curves.Comment: 30 pages, 3 figures. Small corrections, mostly in Section V. To
appear in the Journal of Mathematical Physic