SIMPLE SMARTPHONE BASED SPECTROSCOPIC SYSTEM FOR THE VISUALIZATION AND QUANTIFICATION OF LIGHT SOURCES SPECTRA

In this work we present the implementation of a simple and low cost smartphone based optical spectroscopic system. It is shown how it can be useful for developing both qualitative but also quantitative experiences related with the emission spectra of different light sources. Since smartphones are generalized to all types of public, they represent a very powerful imaging tool that can be exploited for experimental educational demonstrations. Therefore, it is useful for application in scientific museums, as well as for experiments in introductory courses of physics for secondary school and undergraduate students. We have developed a laboratory prototype experience for the visualization of the spectra of different light sources, based on the use of a simple low cost diffraction grating. It avoids the idea of the spectroscope as a “black box” tool. We believe this experiment might be useful for widespread dissemination and understanding of this kind of spectral experiences, since it avoids using specific developed accessories. We expect that visitors and participants will be able to understand the differences in the spectral content and the importance for different technological applications in daily life of different light sources. After that, visitors will be able to explain and discriminate between different common sources like an incandescent light bulb, a LED, or a laser. Finally, they can learn that light, seen as the electromagnetic waves detected in our eye (visible light), can be nowadays extended to other spectral ranges, such as the infrared and the ultraviolet light, respectively.