Experiment with the optical properties of interesting crystals that bend light, such as the “television stone”, Ulexite. When viewed through the television stone, newspaper print appears to be displayed on the stone surface, like on a television, for which the stone is named.
Using your miniature laser level and some other types of crystals (such as the polyacrylamide gel crystals), you can test how different crystals bend light and get your students to identify the crystals based on the angle they bend the light. Crystals are usually identified using x-rays but the laser works just as well here and brings the scale of the experiment up to the visible region. You can also do this experiment with different lenses, to see what lens shapes direct light in which directions.