Beam conditions for radiation generated by an electromagnetic J 0-correlated Schell-model source

Based on the 2 x 2 (electric field) cross-spectral density matrix, a model for an electromagnetic J(0)-correlated Schell-model beam is given that is a generalization of the scalar J(0)-correlated Schell-model beam. The conditions that the matrix for the source to generate an electromagnetic J(0)-correlated Schell-model beam are obtained. The condition for the source to generate a scalar J(0)-correlated Schell-model beam can be considered as a special case. (C) 2008 Optical Society of America

Irish John Willson United Empire Loyalist Family Fonds

John Willson first came to Upper Canada along with his friend Nathaniel Pettit in the late 1700s. They both moved with their families from New Jersey where they had both been imprisioned for not siding with the rebels and maintaining Loyalist allegiences. Pettit arrived with his four daughters, leaving his son behind. Willson came with his wife and nine children. Willson received 1200 acres of land as well as 200 per child. He settled at the corner of Dorchester road and Thorold Stone Road, where he and his family did very well for themselves. Willson as well as his son Thomas ran ox-teams on the portage. His son John became the proprietor of the Exchange hotel at Niagara, and Charles operated at the Pavilion hotel at Falls View. Shortly after his arrival in Upper Canada John Willson changed his name to “Irish” John Willson, as there were 5 other “John Willsons” which appeared on the Loyalists lists. Irish John drowned in the Niagara River in 1798, and his family continued to thrive in Niagara after his death. His second son Thomas Willson, married Abigail Pettit, daughter of his Father’s friend Nathaniel. Thomas was awarded 250 acres of land as a Loyalist and 200 for Abigail, as she was the daughter of a loyalist. He became a blacksmith and also operated ox-teams along the portage. He was Assessor for Stamford Township for 1800, 1807, 1820 and 1829. During the years 1808, 1822, 1825, 1826 and 1831 he was a tax collector and overseer of Statute of Labour. Thomas and Abigail Willson had nine children together. Francis Bond Head Willson of Beaverdams (mentioned throughout the collection) was a great grandson of Thomas and Abigail. Thomas and his wife are both buried beside the Lundy’s Lane United Church. *for more information on the remaining Willson family please refer to box #1, folders 1-3. * Genealogical information from a paper prepared by Pearl Wilson and given before the Lundy’s Lane Historical Society, May 1945, by Hazel Culp Ferris. Box 1 Folder 1.

Marshall Family Papers - Accession 260 - M110 (142)

The Marshall Family Papers includes originals and photocopies of two letters written by Fred D. Marshall of Rock Hill. The first is from Camp Thomas in Chickamauga, Georgia and the second was from Camp Cuba Libre in Jacksonville, FL. while he was a soldier during the Spanish American War to his parents, Capt and Mrs. John Wilson Marshall of Rock Hill Also included is a letter by W.W. Byre to Capt. John Wilson Marshall while a missionary in Mexico. Fred D. Marshall served as mayor of Columbia from 1941 to 1946 and W.W. Byre became Dean of Erskine Theological Seminary at Due West, SC.

Utilizing Gaussian-Schell model beams to mitigate atmospheric turbulence in free space optical communications / by Kyle R. Drexler.

Turbulence affects traditional free space optical communication by causing speckle to appear in the received beam profile. This occurs due to changes in the refractive index of the atmosphere that are caused by fluctuations in temperature and pressure, resulting in an inhomogeneous medium. The Gaussian-Schell model of partial coherence has been suggested as a means of mitigating these atmospheric inhomogeneities on the transmission side. This dissertation analyzed the Gaussian-Schell model of partial coherence by verifying the Gaussian-Schell model in the far-field, investigated the number of independent phase control screens necessary to approach the ideal Gaussian-Schell model, and showed experimentally that the Gaussian-Schell model of partial coherence is achievable in the far-field using a liquid crystal spatial light modulator. A method for optimizing the statistical properties of the Gaussian-Schell model was developed to maximize the coherence of the field while ensuring that it does not exhibit the same statistics as a fully coherent source. Finally a technique to estimate the minimum spatial resolution necessary in a spatial light modulator was developed to effectively propagate the Gaussian-Schell model through a range of atmospheric turbulence strengths. This work showed that regardless of turbulence strength or receiver aperture, transmitting the Gaussian-Schell model of partial coherence instead of a fully coherent source will yield a reduction in the intensity fluctuations of the received field. By measuring the variance of the intensity fluctuations and the received mean, it is shown through the scintillation index that using the Gaussian-Schell model of partial coherence is a simple and straight forward method to mitigate atmospheric turbulence instead of traditional adaptive optics in free space optical communications.