No abstract available

[en] There has been much written over the years about the generation of optical system fabrication, assembly, and alignment tolerances leading to a performance error budget and predicted system performance. Over my 40 years of optical design experience I have become more cautious (and concerned) about how accurately we, the optics community, are tolerancing our systems and predicting their manufactured performance. In this paper I will share with you some of these concerns along with recommended ways of avoiding the many speed bumps, pot holes and other common issues encountered when tolerancing. And of course I will reveal why tolerances don't lie

[en] Engineering students answers wich show difficulties to explain , in very simple optical systems, the relationships between. a) perceived image and the curvature of the wavefront reaching the eye. b) optical system dimensions and the regions from wich complete image can be observed, are analyzed. Possible reasons for these difficulties are considered. The inclusion of the observer eye as well as an elemental model for vision when optical systems are studied is suggested. (Author) 16 refs

[en] This paper deals with a method of measuring the pitch accuracy of raster scales employing Moire fringe technique. The pitch accuracy of angular or linear scales is assessed during the straight-line or circular movement along precise straight or circular trajectory. An index head with a raster scale in conjuction with the raste scale to be measured, results in the Moire fringe pattern. The information about the pitch accuracy is yielded at appropriate intervals of the time or displacement. (orig.)

[en] We study globally coupled chaotic maps modeling an optical system, and find clear evidence of non-statistical behavior: the mean square deviation (MSD) of the mean field saturates with respect to increase in the number of elements coupled, after a critical value, and its distribution is clearly non-Gaussian. We also find that the power spectrum of the mean field displays well defined peaks, indicating a subtle coherence among different elements, even in the ''turbulent'' phase. This system is a physically realistic model that may be experimentally realizable. It is also a higher dimensional example (as each individual element is given by a complex map). Its study confirms that the phenomena observed in a wide class of coupled one-dimensional maps are present here as well. This gives more evidence to believe that such non-statistical behavior is probably generic in globally coupled systems. We also investigate the influence of parametric fluctuations on the MSD. (author). 10 refs, 7 figs, 1 tab

[en] Short communication

[en] Possibilities to obtain the polarization plane rotation amplification and polarization azimuth stabilization with an anisotropic plate in absence of polarization ellipticity are investigated. It is shown, that a resolving ability of an amplifier, which does not introduce a typical for anisotropic plates ellipticity in the passing wave is always smaller than or, at the best, equal to zero. Conditions are found at which the plate works as an ideal stabilizer. The influence of the absorption on the polarization plane rotation amplification is studied. Results of the experimental investigation of the azimuthal non equivalence are presented. 9 refs

[en] Photometry cell for measuring the optical density of fluids and particularly the turbidity of river or nuclear reactor waters or also for detecting pollutants in liquids or gases. The instrument enables the optical path to be extended, and hence the accuracy, by multiple reflexions on spherical mirrors and an optical system operating by transmission. The facilities used to introduce and extract the light beam can be constituted by light guides, particularly optical fibres

[en] Published in summary form only

[en] This paper reports the work done at the 'Osservatorio Astronomico Regionale Parco Antola Comune di Fascia' (OARPAF), as a part of my master thesis. The paper is divided in three parts: the first part describes the instrumentation at the OARPAF; the second part shows the characterization of the instrumentation, from the pointing model of the telescope to the conception and the realization of the software for data analysis; the third part illustrates the results of the photometric calibration.