کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
7932256 1512614 2013 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Defocusing properties of Gaussian beams for measuring refractive index of thin transparent samples
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد مواد الکترونیکی، نوری و مغناطیسی
پیش نمایش صفحه اول مقاله
Defocusing properties of Gaussian beams for measuring refractive index of thin transparent samples
چکیده انگلیسی
We show how the defocusing properties of Gaussian beams can be used to measure the refractive index of solutions in thin transparent samples (less than 2 mm). Additionally, it is possible to predict analytically the shape of the plot for the refractive index as a function of concentration in any range. Our theory is limited for substances whose refractive index increases with concentration. The thin sample is placed between the focusing lens and its back focal plane and the system is adjusted to best focusing conditions. As a result, changes of the refractive index of the sample cause variations of the size of the focused beam. To measure with high accuracy the size of the beam we use the homodyne knife-edge profilometer while profiling a calibrated holographic reflective grating. The recorded vertical heights of the grating provide statistical data for improving even more the accuracy of the measurements. We demonstrate that the sensitivity of the system is a function of the pitch of the grating allowing selecting the range of interest. We apply our method for glucose liquid solutions. We include analytical description of our method and experimental results.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Optics Communications - Volume 309, 15 November 2013, Pages 108-113
نویسندگان
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