19,410 research outputs found
Optical Physics of Imaging and Interferometric Phased Arrays
Microwave, submillimetre-wave, and far-infrared phased arrays are of
considerable importance for astronomy. We consider the behaviour imaging phased
arrays and interferometric phased arrays from a functional perspective. It is
shown that the average powers, field correlations, power fluctuations, and
correlations between power fluctuations at the output ports of an imaging or
interferometric phased array can be found once the synthesised reception
patterns are known. The reception patterns do not have to be orthogonal or even
linearly independent. It is shown that the operation of phased arrays is
intimately related to the mathematical theory of frames, and that the theory of
frames can be used to determine the degree to which any class of intensity or
field distribution can be reconstructed unambiguously from the complex
amplitudes of the travelling waves at the output ports. The theory can be used
to set up a likelihood function that can, through Fisher information, be used
to determine the degree to which a phased array can be used to recover the
parameters of a parameterised source. For example, it would be possible to
explore the way in which a system, perhaps interferometric, might observe two
widely separated regions of the sky simultaneously
A regression technique for evaluation and quantification for water quality parameters from remote sensing data
The objective of this paper is to define optical physics and/or environmental conditions under which the linear multiple-regression should be applicable. An investigation of the signal-response equations is conducted and the concept is tested by application to actual remote sensing data from a laboratory experiment performed under controlled conditions. Investigation of the signal-response equations shows that the exact solution for a number of optical physics conditions is of the same form as a linearized multiple-regression equation, even if nonlinear contributions from surface reflections, atmospheric constituents, or other water pollutants are included. Limitations on achieving this type of solution are defined
Nonlinear optics and light localization in periodic photonic lattices
We review the recent developments in the field of photonic lattices
emphasizing their unique properties for controlling linear and nonlinear
propagation of light. We draw some important links between optical lattices and
photonic crystals pointing towards practical applications in optical
communications and computing, beam shaping, and bio-sensing.Comment: to appear in Journal of Nonlinear Optical Physics & Materials (JNOPM
Searching for New Physics Through AMO Precision Measurements
We briefly review recent experiments in atomic, molecular, and optical
physics using precision measurements to search for physics beyond the Standard
Model. We consider three main categories of experiments: searches for changes
in fundamental constants, measurements of the anomalous magnetic moment of the
electron, and searches for an electric dipole moment of the electron.Comment: Prepared for Comments on AMO Physics at Physica Script
Ultra-Short Optical Pulse Generation with Single-Layer Graphene
Pulses as short as 260 fs have been generated in a diode-pumped low-gain
Er:Yb:glass laser by exploiting the nonlinear optical response of single-layer
graphene. The application of this novel material to solid-state bulk lasers
opens up a way to compact and robust lasers with ultrahigh repetition rates.Comment: 6 pages, 3 figures, to appear in Journal of Nonlinear Optical Physics
& Material
Phase Retrieval with Application to Optical Imaging
This review article provides a contemporary overview of phase retrieval in
optical imaging, linking the relevant optical physics to the information
processing methods and algorithms. Its purpose is to describe the current state
of the art in this area, identify challenges, and suggest vision and areas
where signal processing methods can have a large impact on optical imaging and
on the world of imaging at large, with applications in a variety of fields
ranging from biology and chemistry to physics and engineering
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