In current fiber-optics solutions using multi-wavelength, so on fiber input mixed 8 or more laser waves of different lengths (to be strict not wl but bands) and on output mix divided with optical filter and all wavelengths processed separately.
But you don't have to use exact wavelength in this, you could use any wl within band (yes, 4 colors in each of 40000 bands looking possible), if you have light source with changeable wl and detector with enough precision, and number of wl's could be much larger than in for example LCD or OLED.
Unfortunately, authors of article for some reason don't write about this important nuance, but it mean, in reality to make this technology, need precision light source(s) with adjustable wl's (classic RGB is combination of just 3 wl's, and modern amoleds usually 4 wl's) and precision compact spectrometer (for example, what I seen myself gives 1024 lines for visual spectrum, so just 10 bits). All these are not impossible, but will not easy to achieve.
In current fiber-optics solutions using multi-wavelength, so on fiber input mixed 8 or more laser waves of different lengths (to be strict not wl but bands) and on output mix divided with optical filter and all wavelengths processed separately.
But you don't have to use exact wavelength in this, you could use any wl within band (yes, 4 colors in each of 40000 bands looking possible), if you have light source with changeable wl and detector with enough precision, and number of wl's could be much larger than in for example LCD or OLED.
Unfortunately, authors of article for some reason don't write about this important nuance, but it mean, in reality to make this technology, need precision light source(s) with adjustable wl's (classic RGB is combination of just 3 wl's, and modern amoleds usually 4 wl's) and precision compact spectrometer (for example, what I seen myself gives 1024 lines for visual spectrum, so just 10 bits). All these are not impossible, but will not easy to achieve.