Beam propagation method

The beam propagation method (BPM) is a way to study how light moves through different materials, like glass or plastic. To do this, we use a special computer program that helps us simulate the way the light travels.

Think of the light as a little ball that bounces around inside the material. This ball can move in different directions, and as it travels, it interacts with the material it's passing through.

The program works by dividing up the material into small pieces, like a puzzle, and then tracks how the ball of light moves through each piece. It also takes into account how the ball of light changes as it interacts with the material.

By doing this, we can learn a lot about how light behaves in different materials, and even use the information to design new devices like lasers or fiber optic cables.

So, in short, the beam propagation method is a way to study how light moves through materials by using a computer program to simulate the process.