Given that the laser forms a spot, minor misalignments are very easy to debug (just line up the red spot with the sensor again). Also given a laser with suffici

Given that the laser forms a spot, minor misalignments are very easy to debug (just line up the red spot with the sensor again). Also given a laser with sufficiently wide spread, minor misalignments would manifest themselves as volume loss. Not great if you don't have easy access, but reliable enough for e.g. a dorm room or a living room. This was a lab we did in an intro EE class in college and it worked wonders as a "whoa cool" demonstration with very basic EE knowledge required.