How does a dichroic filter work?

Question

How does a dichroic filter work? Specificaly how does it reflect certain wavelngths and pass other wavelengths. I think it passes wavelengths because these wavelengths do not match the energies of certain electron orbitals. could you provide a fuller explaination. thanks

Answer 1

Dichroic film structures typically consist of one of the following design types: short wave pass, long wave pass, bandpass, or notch filter. These design types comprise the basis of color determination and color separation. Performance is determined by the transmittance and/or reflectance of a band of wavelengths. Transmission in dichroic filters typically average 90% or better.

Answer 2

No, you're wrong. It relies on the thickness of dielectrics to create interference patterns that cancel or enhance the transmission of certain wavelengths of color.

http://en.wikipedia.org/wiki/Dichroic_filter