Dichroic Filter
Dichroic filters (two-color filters) are optical filters and belong to the interference filters or thin-film filters. Dichroic filters are also used as color correction filters to selectively allow light from a small color range to pass through while reflecting other colors. For example, they allow red light to be reflected and blue light to pass through at the same time. For example, all wavelengths that are larger than the edge of the band can be transmitted (long pass). Conversely, all wavelengths that lie below the edge of the band can also be transmitted short pass.
