کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5007853 1461701 2017 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Near-field diffraction-based focal length determination technique
ترجمه فارسی عنوان
تکنیک تعیین طول فاصله کانونی متشکل از پراش فرکانسی نزدیک به میدان
کلمات کلیدی
فاصله کانونی، مترولوژی، خود تصویربرداری،
موضوعات مرتبط
مهندسی و علوم پایه سایر رشته های مهندسی مهندسی برق و الکترونیک
چکیده انگلیسی
An accurate and simple technique for determining the focal length of a lens is presented. It consists of measuring the period of the fringes produced by a diffraction grating at the near field when it is illuminated with a beam focused by the unknown lens. In paraxial approximation, the period of the fringes varies linearly with the distance. After some calculations, a simple extrapolation of data is performed to obtain the locations of the principal plane and the focal plane of the lens. Thus, the focal length is obtained as the distance between the two mentioned planes. The accuracy of the method is limited by the collimation degree of the incident beam and by the algorithm used to obtain the period of the fringes. We have checked the technique with two commercial lenses, one convergent and one divergent, with nominal focal lengths (+100±1) mm and (−100±1) mm respectively. We have experimentally obtained the focal lengths resulting into the interval given by the manufacturer but with an uncertainty of 0.1%, one order of magnitude lesser than the uncertainty given by the manufacturer.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Optics and Lasers in Engineering - Volume 92, May 2017, Pages 105-109
نویسندگان
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