A cool experiment is featured in this video where they make a reverse prism.  Here is more about what they used for this test:

A portable optical circuit that houses 3 laser diodes, a 100mW 532nm Green Laser, a 50 mW 445nm Blue Laser and a 50mW 650nm Red Laser. Using a tunable power supply, up to 7 colors can be made (red, green,blue,yellow,cyan, purple and white). The white laser can be then broken up by dispersion into any of the constituent colors made by the lasers.

This was developed for experiments in making colored holograms, which require the extremely narrow linewidth of the laser sources. Very narrow peaks at red, green and blue wavelengths in the white illumination beam would allow for some color rendering of holographic images. The circuit was also developed and as a test for dichroic mirrors used in combing individual 3W 445nm diode beams into a single powerful laser beam for cutting through material (hopefully a video of this will be available once a suitable portable power supply is made for use outside of a lab)

Let’s check out how their experiment turned out in the video on page 2

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