1,750 research outputs found
Narrow band amplification of light carrying orbital angular momentum
We report on the amplification of an optical vortex beam carrying orbital
angular momentum via induced narrow Raman gain in an ensemble of cold cesium
atoms. A 20\% single-pass Raman gain of a weak vortex signal field is observed
with a spectral width of order of 1 MHz, much smaller than the natural width,
demonstrating that the amplification process preserves the phase structure of
the vortex beam. The gain is observed in the degenerated two-level system
associated with the hyperfine transition of cesium. Our experimental observations are explained
with a simple theoretical model based on a three-level system
interacting coherently with the weak Laguerre-Gauss field and a strong coupling
field, including an incoherent pumping rate between the two degenerate
ground-states.Comment: 9 pages, 4 figure
Effective Communication of 4-H Program Essentials to 4-H Families
Youths and parents in the California 4-H program have reported issues with communication and challenges in understanding the program. As a result, we developed a family handbook and other supporting documents to help youths and parents navigate the California 4-H program. This article addresses the development, dissemination, and reach of the handbook. Additionally, the article discusses future directions and implications for other Extension programs
Relação entre a qualidade de semente e densidade de plantio na produção de milho.
Trabalho apresentado no X Congresso Brasileiro de Sementes
Influência do tipo de corante na análise de danos mecânicos em sementes de milho (Zea mays L.).
xTrabalho apresentado no X Congresso Brasileiro de Sementes, 1997
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