2,363 research outputs found
Systematic Design of Antireflection Coating for Semi-infinite One-dimensional Photonic Crystals Using Bloch Wave Expansion
We present a systematic method for designing a perfect antireflection coating
(ARC) for a semi-infinite one-dimensional (1D) photonic crystal (PC) with an
arbitrary unit cell. We use Bloch wave expansion and time reversal symmetry,
which leads exactly to analytic formulas of structural parameters for the ARC
and renormalized Fresnel coefficients of the PC. Surface immittance (admittance
and impedance) matching plays an essential role in designing the ARC of 1D
PC's, which is shown together with a practical example.Comment: This article may be downloaded for personal use only. Any other use
requires prior permission of the author and the American Institute of Physic
Soft Mode Anomalies in the Perovskite Relaxor Pb(Mg1/3Nb2/3)O3
Neutron inelastic scattering measurements of the polar TO phonon mode in the
cubic relaxor Pb(Mg1/3Nb2/3)O3, at room temperature, reveal anomalous behavior
similar to that recently observed in the Pb(Zn1/3Nb2/3)_{0.92}Ti_{0.08}O3
system in which the optic branch appears to drop precipitously into the
acoustic branch at a finite value of the momentum transfer q = 0.20
1/Angstroms, measured from the zone center. By contrast, a recent neutron study
showed that PMN exhibits a normal TO phonon dispersion at 800 K. We speculate
this behavior is common to all relaxor materials and is the result of the
presence of nanometer-scale polarized domains in the crystal that form below a
temperature Td, which effectively prevent the propagation of long wavelength (q
= 0) phonons.Comment: 5 pages, 4 figures To appear as an AIP Conference Proceedings Volume
for the Aspen 2000 Winter Conference on the Fundamental Physics of
Ferroelectric
Performance, visuality, and textuality : The case of Japanese poetry
The purpose of this paper is to explore the complex relationship among performance, visuality, and textuality, using examples from traditional Japanese poetry, and to reveal how the interaction among these three elements is integral to understanding Japanese poetry as process or action.Issue title: Performance Literature II
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