Thesis (Ph. D.)--University of Texas at Austin, 2001. / Vita. Includes bibliographical references (leaves 94-102). Available also in a digital version from Dissertation Abstracts.

This thesis describes computer simulations of a new wavefront sensing technique for Adaptive Optics based on local wavefront curvature measurements, along with edge slope measurements. The output signal from the curvature measurements, along with edge slope measurements. The output signal from the curvature sensor can be directly applied to the electrodes of a bimorph or membrane mirror. The mirror is used as an analog device to solve the Poisson Equation, providing a fast real time compensation for atmospheric disturbances. The open loop characteristics of the system are presented. The ideal response is analyzed, and side effects such as non-linearity, photon and diffraction noises are discussed. Closed loop simulations are presented thereafter. A seven actuator system showed a few unstable modes. A 13 actuator system with proper filtering corrects the atmospheric perturbations. To simulate atmospheric distorted wavefronts, an algorithm based on spectral decomposition of the Zernike covariance matrix was derived. This sensor can also be used to test large telescope mirrors using a modified program that solves the Poisson Equation with Neumann boundary conditions.

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Photonics is a technology capable of supporting very high bit-rates of data. However, with the current state of photonic technologies logic and memory functions are very difficult to implement in the photonic domain. In photonic star networks using time division multiplexing (such as the Agile All Photonic Network), timeslots from the edges of the network have to arrive at the star point at exactly the same instant to be switched because they cannot be buffered in the photonic domain. The switching requires that the time at which the timeslots are transmitted must be coordinated and tightly controlled. This thesis addresses methods of synchronizing the components at the edge of the network to compensate for heterogeneous propagation delays between the edges and the star point. Different methods of providing this compensation are described and assessed in terms of their capabilities and performance.

Typescript. / Thesis (Ph. D.)--University of Hawaii at Manoa, 1977. / Bibliography: leaves 93-95. / Microfiche. / vii, 95 leaves ill

Typescript. / Thesis (Ph. D.)--University of Hawaii at Manoa, 1990. / Includes bibliographical references (leaves 214-215) / Microfiche. / xv, 215 leaves, bound ill. 29 cm