RESEARCH FROM YEREVAN STATE UNIVERSITY REVEALS NEW FINDINGS ON OPTICAL RESEARCH
Science Letter
September 1, 2009
"The oblique propagation of light through a layer of chiral photonic
crystal (PC) with linear profiles of modulation parameters is
considered. The problem is solved by the method of Ambartsumyan
layer addition," scientists in Yerevan, Armenia report (see also
Optical Research).
"The wavelength dependences of the amplitude characteristics have
been studied at different angles of incidence in two cases, i.e., in
a chiral PC with a linear profile of modulation period and a chiral
PC with a linear profile of modulation depth. It is shown that the
photonic band gap is broadened in both cases and that omnidirectional
reflection occurs under certain conditions. The nonreciprocity
features are investigated for these two cases and it is shown that
a chiral PC with a linear profile of modulation period can operate
as an ideal optical diode in a certain frequency range. The features
of the effect of change in the modulation parameters on the photon
density of states, group velocity, and group velocity dispersion are
analyzed. It is shown that, when the modulation parameters change
in space, the photon density of states at the photonic band gap
edges significantly decreases," wrote A.H. Gevorgyan and colleagues,
Yerevan State University.
The researchers concluded: "It is proposed to use PCs with a spatially
changing modulation period can be used to compress (expand) light
pulses.."
Gevorgyan and colleagues published their study in Optics and
Spectroscopy (Optical properties of chiral photonic crystals with
linear profiles of modulation parameters. Optics and Spectroscopy,
2009;107(1):136-143).
For additional information, contact A.H. Gevorgyan, Yerevan State
University, Yerevan 025, Armenia.
The publisher’s contact information for the journal Optics and
Spectroscopy is: Maik Nauka, Interperiodica, Springer, 233 Spring St.,
New York, NY 10013-1578, USA.
From: Emil Lazarian | Ararat NewsPress
