Anomalous refraction experiment (part 1): Testing Experiment

Aim

Predict what will happen to the laser beam

Prior Knowledge

• Reflection
• Refraction, refractive index, and total internal reflection

Description of the Experiment

The first movie shows the experimental set-up. A laser is set at an angle as shown, shining into a rectangular plexi-glass block. It is shown that at the angle that the laser beam strikes the top surface of the block, it undergoes total internal reflection. Water drops are placed on top of the block to make a large water drop.

In the second movie the laser beam will be moved so that it "sweeps" across the top of the block and the water drop. You have to predict what will happen to the reflected laser beam as the beam moves across the drop. Use your model of refraction and the conditions for total internal reflection to make your prediction.

Youtube movies can be stepped frame by frame using the , and . keys on your keyboard. If you want to download the movie to your computer, right-click or control-click HERE.

Youtube movies can be stepped frame by frame using the , and . keys on your keyboard. If you want to download the movie to your computer, right-click or control-click HERE.

Questions

If your predictions did not match the outcome of the experiment, can you come up with an explanation of what you saw?