Optical window

An optical window is like a special piece of glass that lets light pass through it. Think of it like a window in your house. Just like how you can look out of a window, things can also go through an optical window like light.

But this special glass is different because it needs to work really well. It needs to be very clear and smooth. This way, light can go through without getting bent or scattered. This is really important if you want to see things far away or if you want to use a microscope or telescope.

Also, an optical window needs to be made out of special materials. The glass used in an optical window can be really expensive because it has to be strong and not have any impurities. This way, the window doesn't break or get scratched easily.

Overall, an optical window is like a special window that is really good at letting light through so we can see things better.