140 research outputs found
Unitary transformation for the system of a particle in a linear potential
A unitary operator which relates the system of a particle in a linear
potential with time-dependent parameters to that of a free particle, has been
given. This operator, closely related to the one which is responsible for the
existence of coherent states for a harmonic oscillator, is used to find a
general wave packet described by an Airy function. The kernel (propagator) and
a complete set of Hermite-Gaussian type wave functions are also given.Comment: Europhysics Letters (in press
Hermite Coherent States for Quadratic Refractive Index Optical Media
ProducciĂłn CientĂficaLadder and shift operators are determined for the set of Hermite–Gaussian modes associated with an optical medium with quadratic refractive index profile. These operators allow to establish irreducible representations of the su(1, 1) and su(2) algebras. Glauber coherent states, as well as su(1, 1) and su(2) generalized coherent states, were constructed as solutions of differential equations admitting separation of variables. The dynamics of these coherent states along the optical axis is also evaluated.MINECO grant MTM2014-57129-C2-1-P and Junta de Castilla y Leon grant VA057U16
Classical simulation of Quantum Entanglement using Optical Transverse Modes in Multimode Waveguides
We discuss mode-entangled states based on the optical transverse modes of the
optical field propagating in multi-mode waveguides, which are classical analogs
of the quantum entangled states. The analogs are discussed in detail, including
the violation of the Bell inequality and the correlation properties of optical
pulses' group delays. The research on these analogs may be important, for it
not only provides useful insights into fundamental features of quantum
entanglement, but also yields new insights into quantum computation and quantum
communication.Comment: RevTeX v4, 17 pages and 4 figure
Modelling Quantum Mechanics by the Quantumlike Description of the Electric Signal Propagation in Transmission Lines
It is shown that the transmission line technology can be suitably used for
simulating quantum mechanics. Using manageable and at the same time
non-expensive technology, several quantum mechanical problems can be simulated
for significant tutorial purposes. The electric signal envelope propagation
through the line is governed by a Schrodinger-like equation for a complex
function, representing the low-frequency component of the signal, In this
preliminary analysis, we consider two classical examples, i.e. the Frank-Condon
principle and the Ramsauer effect
Computational studies of light acceptance and propagation in straight and curved multimodal active fibres
A Monte Carlo simulation has been performed to track light rays in
cylindrical multimode fibres by ray optics. The trapping efficiencies for skew
and meridional rays in active fibres and distributions of characteristic
quantities for all trapped light rays have been calculated. The simulation
provides new results for curved fibres, where the analytical expressions are
too complex to be solved. The light losses due to sharp bending of fibres are
presented as a function of the ratio of curvature to fibre radius and bending
angle. It is shown that a radius of curvature to fibre radius ratio of greater
than 65 results in a light loss of less than 10% with the loss occurring in a
transition region at bending angles of pi/8 rad.Comment: 21 pages, 13 figure
Nineteen-port photonic lantern with multimode delivery fiber
We demonstrate efficient multimode (MM) to single-mode (SM) conversion in a 19-port photonic lantern with a 50 ÎĽm core MM delivery fiber. The photonic lantern can be used within the field of astrophotonics for coupling MM starlight to an ensemble of SM fibers in order to perform fiber-Bragg-grating-based spectral filtering. An MM delivery fiber spliced to the photonic lantern offers the advantage that the delivery fiber guides the light from the focal plane of the telescope to the splitter. Therefore, it is no longer necessary to have the splitter mounted directly in the focal plane of the telescope. The coupling loss from a 50 ÎĽm core MM fiber to an ensemble of 19 SM fibers and back to a 50 ÎĽm core MM fiber is below 1.1 dB.3 page(s
Slow Light Propagation in a Thin Optical Fiber via Electromagnetically Induced Transparency
We propose a novel configuration that utilizes electromagnetically induced
transparency (EIT) to tailor a fiber mode propagating inside a thin optical
fiber and coherently control its dispersion properties to drastically reduce
the group velocity of the fiber mode. The key to this proposal is: the
evanescent-like field of the thin fiber strongly couples with the surrounding
active medium, so that the EIT condition is met by the medium. We show how the
properties of the fiber mode is modified due to the EIT medium, both
numerically and analytically. We demonstrate that the group velocity of the new
modified fiber mode can be drastically reduced (approximately 44 m/sec) using
the coherently prepared orthohydrogen doped in a matrix of parahydrogen crystal
as the EIT medium.Comment: 10 pages in two column RevTex4, 6 Figure
Frank-Condon principle and adjustment of optical waveguides with nonhomogeneous refractive indices
The adjustment of two different selfocs is considered using both exact
formulas for the mode-connection coefficients expressed in terms of Hermite
polynomials of several variables and a qualitative approach based on the
Frank-Condon principle. Several examples of the refractive-index dependence are
studied and illustrative plots for these examples are presented. The connection
with the tomographic approach to quantum states of a two-dimensional oscillator
and the Frank-Condon factors is established.Comment: 8 pages, 4 figures, published version (layout of figures changed,
typos corrected, references added
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