There are no "individual wavelengths", ever, anywhere. Do you mean modulating multiple bands of light, as a TV does with broad-bands of R, G, & B? Do you mean

There are no "individual wavelengths", ever, anywhere. Do you mean modulating multiple bands of light, as a TV does with broad-bands of R, G, & B? Do you mean time-band modulation of a single band, like radios do with AM?