Showing papers by "Alberto Cordero-Dávila published in 2001"
TL;DR: A LED in a Ronchi tester can be used to obtain two main improvements: it can choose one of two wavelength bands to illuminate and record the ronchigram and it can change the irradiance of the illumination source according to the optical system under test and the detector array.
Abstract: We used a LED in a Ronchi tester to obtain two main improvements: (i) We can choose one of two wavelength bands to illuminate and record the ronchigram, and (ii) we can change the irradiance of the illumination source according to the optical system under test and the detector array. This can be done by use of an adequate electronic circuit.
9 citations
TL;DR: An algorithm that uses a square grid in a Ronchi test that applies only one nonlinear least-squares fit to the dot coordinates to calculate the optical path difference.
Abstract: We present an algorithm that uses a square grid in a Ronchi test. We assume that the point coordinates of this pattern (termed a bironchigram) are affected by Gaussian errors. To calculate the optical path difference, we apply only one nonlinear least-squares fit to the dot coordinates. The relevant equations are deduced, and experimental results are shown.
3 citations
04 Jun 2001
TL;DR: In this paper, the behavior of a segmented spherical corrector ring for a scaled telescope (1/14.16) was tested with a stop diameter of 15.53 cm (220 cm).
Abstract: In order to verity our computer simulations, we made and tested the behavior of a segmented spherical corrector ring for our scaled telescope (1/14.16). We increased the stop diameter from 12 cm (170 cm) to 15.53 cm (220 cm). And we have obtained the results that we had calculated, this means that the spot size can be kept with the aid of the spherical corrector rings even when the stop diameter is increased.
2 citations
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04 Jun 2001
TL;DR: In this paper, the authors used a light emitting diode (LED) in the Ronchi tester in order to obtain two main improvements: a) choosing one of two wavelength bands to illuminate and record the ronchigram, and b) changing the irradiance of the illumination source according to the optical system under test and the detector array.
Abstract: We have used a LED (Light Emitting Diode) in the Ronchi tester in order to obtain two main improvements: a) we can choose one of 2 wavelength bands to illuminate and record the ronchigram, and b) we can change the irradiance of the illumination source according to the optical system under test and the detector array. This can be done by using an adequate electronic circuit.