Start: 01/08/09
End: 01/31/12
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 A paper by Henry Sztul, a Ph.D. candidate in physics, and his mentor, Dr. Robert R. Alfano, CUNY Distinguished Professor of Science and Engineering at CCNY, was cited as one of the most exciting research developments in optics for 2008 by “Optics and Photonics News.” Mr. Sztul and Professor Alfano explored the propagation dynamics of Airy beams, which are laser beams that travel in a curved rather than straight path. They found that as the beam travels along its arc its main lobe, or brightest part, is consistently pointed at a 45 degree angle to the X axis. However, the Poynting vector, which describes the magnitude and direction of the energy flow from the Airy beam’s tail, points in a negative Y or negative X direction. This indicates the energy in the tail is flowing toward the beam’s main lobe. Mr. Sztul and Professor Alfano also found that while the net angular momentum around the Z-axis was always zero, the spatial distribution of the angular momentum had changing values. “The study shows the spatial evolution of the Airy solution to the paraxial wave equation,” Professor Alfano said. “While momentum is changing, energy and momentum are conserved.” |