In this work a new type of partially polarized and partially coherent sources is proposed. The coherence characteristics of these sources are dependent on the difference of the radial distances from the source center of the two points to be compared. The coherence is perfect for points located on the same circle centered on the source center and decreases for points that belongs to different concentric circles. The maximum attainable coherence is related to the degree of polarization of the source. Coherence and polarization characteristics of this kind of fields at the source plane and upon free space propagation are analyzed in detail for a simple case. For the particular presented example, a partially polarized and partially coherent field is obtained, whose polarization properties are invariant in propagation.
The generation of non-uniformly totally polarized beams and the study of their applications is a subject of increasing interest in the last years. A particular class of beams of this kind are the so-called <i>full Poincaré beams</i>, which have the property of presenting all possible polarization states across their transverse section. Here we present a simple and easy way to obtain a beam endowed with such property. The method is based on the use of an initially linearly polarized beam that propagates along the optic axis of a uniaxial crystal.
Several overall parameters are introduced to characterize the linear or circular polarization content of a non-uniformly totally polarized beam over the region of its wavefront where the irradiance is significant. These parameters are determined from the values of the Stokes parameters. Experimental examples are also given to check both, the physical meaning of the proposed parameters and the validity of the measurement procedure.
More than 60 demonstrations and basic experiments in Optics have been compiled. They can be carried out by secondary and university students in the classroom or at home, and have been conceived considering low cost and easy-to-get materials. The goal is to offer didactic resources, showing that Optics can be taught in an attractive and amusing way. The experiments try to stimulate scientific curiosity, and generate interest in the observation of our physical world. The work could be collected as a book, where each demonstration would be contained in one or two pages, including a title, a list of the required materials and a concise explanation about what to do and observe. Associated with the experimental content, we propose a web page, namely, <a href="http://www.ucm.es/info/expoptic">http://www.ucm.es/info/expoptic</a>, that accepts experiments sent by anyone interested in Optics, which can be used as a forum to interchange information on this educational topic.
Use of anisotropic pure phase plates to improve the quality parameter of certain partially coherent and partially polarized beams is investigated. Analytical expressions for the beam quality after propagation through these anisotropic transmittances are obtained. Conditions to get the best quality are also derived.
The behavior of the so-called generalized degree of polarization of partially coherent partially polarized beams upon free propagation is investigated. On the basis of this parameter a general classification scheme of partially polarized beams is proposed. The results are applied to certain classes of fields of special interest.
As is well-known, pure-phase transmittances are not, in general, first-order optical systems. It thus seems that a simple ABCD-propagation law cannot be applied to this kind of transmittance. In other words, such optical elements could not be characterized by an overall ABCD matrix. The aim of the present contribution is to overcome this trouble. In fact, the propagation laws of the intensity moments of a laser beam through ABCD optical systems are generalized to include pure phase transmittances. This is done by representing the behavior of such transmittances by means of a 4 by 4 matrix, M, which can be handled, to some extent, as the ABCD-matrices associated with ordinary first-order optical systems. This formalism enables the application of ABCD propagation formulae to cascaded optical systems containing pure phase transmittances. Matrix M is applied, in particular, to determine the intensity moments and the beam quality parameter at the output of special quartic phase transmittances, namely, thin and thick spherically aberrated lenses.