Prism Uses in Home Science Experiments

Quick answer

You can easily explore light behavior at home using a triangular prism to split white light into a rainbow and a beam splitter cube to divide a laser beam.

Step-by-step prism experiments

1. 1. Make a rainbow with a triangular prism: Hold the Triangular BK7 Optical Prism in a sunbeam or in front of a bright white flashlight. Rotate it slowly until a rainbow band appears on a white wall or paper. The prism bends different colors at slightly different angles, separating white light into its component hues. Common mistake: using a cloudy day or dim light source. Bright, direct light gives the clearest spectrum.
2. 2. Split a laser beam with a beam splitter cube: Shine a laser pointer (low power, eye-safe) directly into one face of the Beam Splitter Optical Cube Prism. Observe two beams exiting: one continues straight, the other turns 90 degrees. This shows how the cube divides the beam into two equal-intensity paths. Checkpoint: always point the laser away from eyes and reflective surfaces. The cube works best when the laser hits the center of the face.
3. 3. Recombine the split beams: Place two small mirrors to redirect the two beams from the beam splitter cube so they meet again on a distant surface. Adjust the mirrors until the spots overlap. Notice the combined spot is as bright as the original—proving the cube only splits, not weakens, the light. Common mistake: mirrors not aligned. Use a dark room to see faint spots and align them precisely.

What you need

• Triangular BK7 Optical Prism: Made from BK7 optical glass with a precise triangular shape for exceptional light manipulation. BK7 glass gives clearer, brighter rainbows than cheaper acrylic prisms, so the color separation is more vivid.

  

• Beam Splitter Optical Cube Prism: A cube-shaped prism that splits an incoming light beam into two separate paths. It lets you demonstrate beam splitting and recombination, which is harder to show with a triangular prism alone.