Coupled mode theory

Coupled mode theory is like playing with two toy cars that are connected with a rubber band. When you pull one car, the other one moves too!

But, in science, we use it to understand things like light moving through different materials or how sound waves travel through two different objects.

The rubber band in the toy cars is like the "coupling" between the two materials. When light or sound waves move from one material to another, they can be affected by the way the two materials are connected.

Coupled mode theory helps us understand how the light or sound waves will be affected by the connection between the two materials. We can use math to figure out how much of the light or sound waves will go from one material to the other, and how much will stay in one place.

So, think of it like playing with toy cars, but instead of playing, we're using it to learn about how different materials work together.