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Título:
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Dual self-image technique for beam collimation
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Autores:
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Herrera Fernández, José María ;
Sánchez Brea, Luis Miguel ;
Torcal Milla, Francisco José ;
Morlanes Calvo, Tomás ;
Bernabeu Martínez, Eusebio
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Tipo de documento:
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texto impreso
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Editorial:
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IOP Publishing, 2016-06-14
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Dimensiones:
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application/pdf
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Nota general:
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info:eu-repo/semantics/openAccess
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Idiomas:
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Palabras clave:
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Estado = Publicado
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Materia = Ciencias: Física: Optica
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Tipo = Artículo
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Resumen:
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We propose an accurate technique for obtaining highly collimated beams, which also allows testing the collimation degree of a beam. It is based on comparing the period of two different self-images produced by a single diffraction grating. In this way, variations in the period of the diffraction grating do not affect to the measuring procedure. Self-images are acquired by two CMOS cameras and their periods are determined by fitting the variogram function of the self-images to a cosine function with polynomial envelopes. This way, loss of accuracy caused by imperfections of the measured self-images is avoided. As usual, collimation is obtained by displacing the collimation element with respect to the source along the optical axis. When the period of both self-images coincides, collimation is achieved. With this method neither a strict control of the period of the diffraction grating nor a transverse displacement, required in other techniques, are necessary. As an example, a LED considering paraxial approximation and point source illumination is collimated resulting a resolution in the divergence of the beam of ? ? = ± ?rad.
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En línea:
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https://eprints.ucm.es/39228/1/SBrea%2004%20Prepr.pdf
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