Bonn 2020 – scientific programme

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DD: Fachverband Didaktik der Physik

DD 16: Postersitzung

DD 16.41: Poster

Wednesday, April 1, 2020, 16:30–18:00, P-SR 1-4

An educational experiment to measure laser beam spatial profile by a galvanometer scanner and a CCD sensor — •Nikolaos Merlemis¹ and Ioannis Sianoudis² — ¹Department of Surveying and Geoinformatics, University of West Attica, Athens, Greece, merlemis@uniwa.gr — ²Department of Biomedical Sciences, University of West Attica, Athens, Greece, jansian@uniwa.gr

In several undergraduate courses related to laser physics and optics it is crucial that students be able to understand basic concepts of laser beam propagation. Recent advances in CCD sensors have made the measurement of laser beam spatial profile easy and accurate; however, the cost of an industrial grade laser beam profiler may be elevated and the pedagogical impact of an experiment based on such a device may be lower than expected. With this in mind, we propose an experiment based on two parallel apparatuses: The first is based on a modified knife-edge technique where instead of using a spinning blade to cut the beam, a galvanometer scanner is employed to drive the laser through a small pinhole in order to record the intensity passing with a photodiode. The second experiment is based on direct measurement of laser intensity with a CCD sensor. Students are able to plot the beam intensity versus distance from the centre of the beam, calculate the beam width and divergence and compare the two methods. There is evidence that the proposed experiment awakens the motivation and interest in courses such as laser physics, optical communications and remote sensing technologies.