Can you change the wavelength of light by putting a filter on it?
1 Answer
Mar 6, 2016
No, filters don't change the wavelength of light.
Explanation:
Light from the sun and most lamps contain light of a mixture of different wavelengths. A filter allows only certain wavelengths through and absorbs the others.
So, a red filter doesn't change the wavelength of light to red. It simply removes all but the red wavelengths from all light passing through it.
The wavelength of light can be changed if the light is first absorbed by electrons of a substance to put them into an excited energy state. When the electrons returns to their ground state they will emit light of the particular wavelength corresponding to the energy difference between the two states.
