Are there Phosphors that react only to specific frequencies of light? Answered
Are there phosphors that only produce a color of visible light when struck by a specific frequency?
If so, what would happen if this phosphor was struck be two beams of light at right angles, with each beam at half the "trigger" frequency? If this would not result in an effective "trigger" frequency at that point, is there another method of achieving that effective frequency at a point, with two beams crossing at a single point, where the phosphor lies?