Experimental generation and characterization of Devil's vortex-lenses

We propose the first experimental approach for both generation and characterization of high quality Devil's vortex-lenses. These new type of lenses, able to produce a sequence of optical vortices, are addressed onto a programmable spatial light modulator (SLM) operating in phase-only modulation. The static aberrations arising by the lack of flatness of the SLM display are characterized and mostly compensated by using a Shack - Hartmann wavefront sensor. The analysis of the residual aberrations and their effect on the vortex-lens performance are studied. © Springer-Verlag 2012.The financial support of the Spanish Ministry of Science and Innovation under projects DPI2008-02953, TRA2009-0215 and TEC2010-20307 is acknowledged. We also acknowledge the support from Generalitat Valenciana through the project PROMETEO2009-077. J.A.R. gratefully acknowledges a "Juan de la Cierva" grant and the financial assistance provided by the Universitat Politecnica de Valencia (grants PAID-02-10 and PAID-5-11). L. R. acknowledges a fellowship of "Fundacion Cajamurcia", Spain.Calatayud Calatayud, A.; Rodrigo, J.; Remón Martín, L.; Furlan, W.; Cristóbal, G.; Monsoriu Serra, JA. (2012). Experimental generation and characterization of Devil's vortex-lenses. Applied Physics B. 106:915-919. https://doi.org/10.1007/s00340-012-4913-0S915919106K. Crabtree, J.A. Davis, I. Moreno, Appl. Opt. 43, 1360 (2004)F.S. Roux, Opt. Commun. 242, 45 (2004)G. Gbur, T.D. Visser, Opt. Commun. 259, 428 (2006)W.M. Lee, X.-C. Yuan, W.C. Cheong, Opt. Lett. 29, 1796 (2004)S.H. Tao, X.-C. Yuan, J. Lin, R. Burge, Appl. Phys. Lett. 89, 031105 (2006)G. Saavedra, W.D. Furlan, J.A. Monsoriu, Opt. Lett. 28, 971 (2003)J.A. Rodrigo, T. Alieva, M.L. Calvo, J.A. Davis, J. Mod. Opt. 52, 2771 (2005)J.A. Monsoriu, W.D. Furlan, G. Saavedra, F. Giménez, Opt. Express 15, 13858 (2007)W.D. Furlan, F. Giménez, A. Calatayud, J.A. Monsoriu, Opt. Express 17, 21891 (2009)W.D. Furlan, F. Giménez, A. Calatayud, L. Remon, J.A. Monsoriu, J. Eur. Opt. Soc., Rapid Publ. 5, 10037s (2010)D.R. Chalice, Am. Math. Mon. 98, 255 (1991)J.A. Davis, L. Ramirez, J.A.R. Martín-Romo, T. Alieva, M. Calvo, Opt. Lett. 29, 1321 (2004)A. Lizana, A. Márquez, L. Lobato, Y. Rodange, I. Moreno, C. Iemmi, J. Campos, Opt. Express 18, 10581 (2010)C. López-Quesada, J. Andilla, E. Martín-Badosa, Appl. Opt. 48, 1084 (2009)J.A. Rodrigo, T. Alieva, A. Cámara, O. Martínez-Matos, P. Cheben, M.L. Calvo, Opt. Express 19, 6064 (2011)R.J. Noll, J. Opt. Soc. Am. 66, 207 (1976)M. Born, E. Wolf, Principles of Optics (Cambridge University Press, Cambridge, 1999)R.K. Singh, P. Senthilkumaran, K. Singh, J. Opt. A, Pure Appl. Opt. 10, 075008 (2008)A. Sakdinawat, Y. Liu, Opt. Lett. 32, 2635 (2007

Comportamento de fungos e de sementes de feijoeiro durante o teste de envelhecimento artificial Behavior of fungi and of bean seeds during the artificial aging test

O teste de envelhecimento artificial, recomendado para avaliar o vigor de lotes de sementes, apresenta variabilidade em seus resultados; a ação dos fungos é considerada uma das causas dessa variabilidade. Este trabalho objetivou verificar os efeitos de diferentes períodos de envelhecimento artificial, no comportamento fisiológico de sementes do feijoeiro e dos fungos Aspergillus spp., Penicillium spp., Fusarium oxysporum e Colletotrichum lindemuthianum, inoculados artificialmente. Foram conduzidos testes de sanidade, germinação, tetrazólio, emergência, condutividade elétrica e lixiviação de potássio. As respostas obtidas, dependentes da duração do período de envelhecimento, indicaram efeitos da espécie fúngica presente. Concluiu-se que o teste de envelhecimento artificial associa a expressão de causas fisiológicas e sanitárias, o que prejudica a interpretação dos dados obtidos; a presença de fungos, principalmente de Aspergillus spp., pode ser considerada como capaz de interferir de modo negativo no desempenho das sementes envelhecidas artificialmente.<br>Although recommended for evaluation of seed lot vigor, artificial aging test shows results variability for reasons yet to be elucidated. Seed-fungi association is considered one of the causes responsible for such variation. The goal of this work was to verify the effects of periods of artificial aging on bean seed behavior and on Aspergillus spp., Penicillium spp., Fusarium oxysporum and Colletotrichum lindemuthianum fungi artificially inoculated by contact method. Health, germination, tetrazolium, emergence, electrical conductivity and potassium leaching tests were performed for seed behavior evaluation. The answers achieved, besides dependable on the aging time period, indicated the effect of fungi species associated to the seed. The artificial aging test was found to be associated with the expression of physiological and sanitary causes that interfere with data interpretation; the presence of fungi, mainly Aspergillus spp., may be considered capable of interfering in the behavior of artificially aged seeds in a negative way