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Publicações

Publicações por CTM

1995

CROSS-CORRELATION BETWEEN I(DD) AND V(OUT) SIGNALS FOR TESTING ANALOG CIRCUITS

Autores
DASILVA, JM; MATOS, JS; BELL, IM; TAYLOR, GE;

Publicação
ELECTRONICS LETTERS

Abstract
The cross-correlation between i(DD) and v(out) signals is addressed as a means for improving the testing of analogue circuits. Besides the higher testing confidence provided by mixed i(DD)/v(out) monitoring, a single unified test operation is performed instead of two separate operations.

1995

BRIGHT, DARK, AND GRAY SPATIAL SOLITON STATES IN PHOTOREFRACTIVE MEDIA

Autores
CHRISTODOULIDES, DN; CARVALHO, MI;

Publicação
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS

Abstract
A theory based on the Kukhtarev-Vinetskii model is developed that provides the evolution equation of one-dimensional optical spatial solitons in photorefractive media. In the steady-state regime and under appropriate external bias conditions, our analysis indicates that the underlying wave equation can exhibit bright and dark as well as gray spatial soliton states. The characteristics of these self-trapped optical beams are discussed in detail. (C) 1995 Optical Society of America

1995

SELF-DEFLECTION OF STEADY-STATE BRIGHT SPATIAL SOLITONS IN BIASED PHOTOREFRACTIVE CRYSTALS

Autores
CARVALHO, MI; SINGH, SR; CHRISTODOULIDES, DN;

Publicação
OPTICS COMMUNICATIONS

Abstract
The self-bending process of steady-state bright spatial solitons in biased photorefractive media is investigated by taking into account diffusion effects. By integrating numerically the nonlinear propagation equation, it is found that the soliton beam evolution is approximately adiabatic. The self-deflection process is further studied using perturbation analysis, which predicts that the center of the optical beam moves on a parabolic trajectory and, moreover, that the central spatial frequency component shifts linearly with the propagation distance. Relevant examples are provided.

1995

VECTOR PHOTOREFRACTIVE SPATIAL SOLITONS

Autores
SEGEV, M; VALLEY, GC; SINGH, SR; CARVALHO, MI; CHRISTODOULIDES, DN;

Publicação
OPTICS LETTERS

Abstract
We derive vector soliton solutions for photorefractive media in which the refractive-index perturbations must be treated as tensors. The two polarizations of the vector solitons may be coupled through the space-charge field alone and/or through cross terms in the electro-optic tenser, which requires phase matching and specific configurations. We analyze bright planar vector solitons and verify their stability. (C) 1995 Optical Society of America

1995

VECTOR INTERACTIONS OF STEADY-STATE PLANAR SOLITONS IN BIASED PHOTOREFRACTIVE MEDIA

Autores
SINGH, SR; CARVALHO, MI; CHRISTODOULIDES, DN;

Publicação
OPTICS LETTERS

Abstract
A theory describing the steady-state propagation of orthogonally polarized planar bright beams in biased photorefractive media is developed. Interactions between soliton states of each polarization in a strontium barium niobate photorefractive crystal are then investigated numerically. Our results indicate that such vector interactions can lead to a number of interesting effects such as beam compression and beam steering. (C) 1995 Optical Society of America

1995

Incoherently coupled soliton pairs in biased photorefractive crystals

Autores
Christodoulides, DN; Singh, SR; Carvalho, MI; Segev, M;

Publicação
Applied Physics Letters

Abstract
We show that incoherently coupled soliton pairs are possible in biased photorefractive crystals, under steady-state conditions. These solitons can propagate in bright-bright, dark-dark, as well as in bright-dark configurations. Such soliton pairs can be established provided that the carrier beams share the same polarization, wavelength, and are mutually incoherent. Relevant examples are provided where the photorefractive crystal is of the strontium barium niobate type. The characteristics and stability properties of these soliton states are also discussed in detail. © 1996 American Institute of Physics.

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