ELI5: Explain Like I'm 5

optical frequency multiplier

Okay, so you know how sometimes you play with Legos and you can build bigger things by putting smaller pieces together? An optical frequency multiplier is kind of like that, but with light waves instead of Legos!

You see, light is made up of tiny particles called photons that travel in waves. These waves have a certain frequency, which tells us how many times the wave goes up and down in a second. For example, if a wave goes up and down 100 times in one second, we say it has a frequency of 100 Hertz (Hz).

But what if we want to make a wave with a higher frequency? That's where the optical frequency multiplier comes in! It takes a lower-frequency light wave and uses a special material (usually a crystal) to "multiply" its frequency and make it higher.

Here's how it works: when the lower-frequency light waves pass through the crystal, they cause the atoms in the crystal to vibrate in a certain way. This vibration creates new waves that have frequencies that are multiples of the original frequency. So if the original wave had a frequency of 100 Hz, the crystal might create new waves with frequencies of 200 Hz, 300 Hz, and so on.

The result is a bunch of new light waves that have higher frequencies than the original wave. And why would we want higher-frequency light waves? Well, they can be useful in things like telecommunications (sending signals over long distances), laser cutting, and scientific research.

So there you have it! An optical frequency multiplier is like a Lego tool that lets us build bigger, higher-frequency light waves out of smaller ones.