Using flatbed scanners in the undergraduate optics laboratory-An example of frugal science

We describe the use of a low-cost commercial flatbed scanner in the undergraduate teaching laboratory to image large (similar to 25 cm) interference and diffraction patterns in two dimensions. Such scanners usually have an 8-bit linear photosensor array that can scan large areas (similar to 28 cm x 22 cm) at very high spatial resolutions (similar to 100 Megapixels), which makes them versatile large-format imaging devices. We describe how the scanner can be used to image interference and diffraction from rectangular single-slit, double-slit, and circular apertures. The experiments are very simple to setup and require no specialized components besides a small laser and a flatbed scanner. Due to the presence of Automatic Gain Control in the scanner, which we were not able to override, we were unable to get an excellent fit to the data. Interestingly, we found that the less-than-ideal data were actually pedagogically superior as it forced the students to think about the process of data acquisition in much greater detail instead of simply performing the experiment mechanically. (C) 2017 American Association of Physics Teachers.