Ignasi Juvells

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We present a method to detect patterns in defocused scenes by means of a joint transform correlator. We describe analytically the correlation plane, and we also introduce an original procedure to recognize the target by postprocessing the correlation plane. The performance of the methodology when the defocused images are corrupted by additive noise is also(More)
Polarisers are one of the most widely used devices in optical set-ups. They are commonly used with paraxial beams that propagate in the normal direction of the polariser plane. Nevertheless, the conventional projection character of these devices may change when the beam impinges a polariser with a certain angle of incidence. This effect is more noticeable(More)
We propose a method for tailoring light spots in the focal region with tunable polarization and shape using a single high focusing system. The proposed method is based in the relationship between the polarization distribution in the input beam and the filed distribution in the focal region. We introduce an incident vortex field with two arbitrary parameters(More)
Recently, a variety of applications requiring the use of non-uniformly polarized beams have been described. Moreover, digital holography using liquid crystal displays has provided a way of implementing in practice such beams. In particular, in the field of optical security, this type of beams has become very important since information can be encrypted(More)
In this communication we analyze the feasibility of experimentally implementing arbitrary three-dimensional vectorial distributions in the focal area of a converging lens. The analysis is carried out using the framework of the closest electromagnetic field to a target vectorial function. An optical setup based on the use of liquid crystal devices and an(More)
Optical trapping is an attractive and multidisciplinary topic that has become the center of attention of a large number of researchers. Moreover, it is a suitable subject for advanced students that requires a knowledge of a wide range of topics. As a result, it has been incorporated into some syllabuses of both undergraduate and graduate programs. In this(More)
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