Results

Determine the width of each opening and obstacle. See appendix for the laser wavelength.

• For the diffraction grating, the angle to each order is large so the approximation for  y<<R  cannot be used. The grating spacing is then best determined by calculating  n/(sin q)   for each order and averaging the values.

• For the slits and obstacles where the angle to each order is small, the width is best determined by plotting n and y. Then d is determined using the graph slope with the small angle approximation. Note: there may be missing orders which can be identified on the graph.

A note on use of original data

The original sketches of diffraction patterns form part of the data in your notes, as does spacing measurements from these sketches (and even possibly samples of what was used in the experiment such as from the hair part). Originals are not submitted for presentation or publication. Originals are part of the integrity of your notes, supporting subsequent work that is based on your notes (such as publishing or presenting your work)