Building a spectrometer with a 3D printer and a webcam.Almost all optics in a single experiment.

Abstract

Exposing the student to the challenge of designing an instrument throughout an entire semester course is proposed. The spectrometer has the virtue of involving almost all the concepts that appear in an optics course. The flexibility of the design allows handling different alternatives: improving the resolution by changing the observed order at the expense of loss of intensity, changing the distance and width of the slit, the grating input angle, etc. Learning includes testing the reliability of the instrument and understanding the importance of calibration (a practice that is necessary to acquire in the use of any instrument). To give versatility to the design, the use of a 3D printer has been chosen for this development. A webcam was selected for the detection not only due to its low cost, but mainly because it forcesthe user to look for signal processing mechanisms in order to compensate for distortions such as aberrations, spectral filters, and low dynamic range.