Dichroic filter

A dichroic filter is a special type of filter that only lets certain colors of light pass through. Imagine you have a box with a bunch of different colored balls inside. If you wanted to only let the red and blue balls out of the box, you could use a dichroic filter to do that.

The filter is made up of two different layers, each with its own special job. The first layer is like a mirror that reflects certain colors of light and lets others pass through. The second layer is like a window that only lets the colors of light that pass through the first layer continue on their way.

When light shines on the filter, some of the colors will be reflected and others will be allowed to pass through. This happens because different colors of light have different energy levels and the different layers of the filter are designed to respond to specific energy levels. So, the red and blue colors might pass through while the green and yellow colors will be reflected back.

Dichroic filters are used in all kinds of places, like in cameras to improve picture quality, in theater lighting to create special effects, and even on the front of some buildings to reflect sunlight and keep the inside of the building cooler.