What are some uses for this? This is not my field so any types of experiments is nice that would help understand some general use cases. The last time I used o

What are some uses for this? This is not my field so any types of experiments is nice that would help understand some general use cases. The last time I used one of these was for my physics "optics" lab. If I recall correctly, we used a grater of some sort which filtered out the light wavelengths which was displayed. It was so long ago, I can't recall the lab project.