The addition of white light will cause a desaturation of the monochromatic source, as perceived by the human eye.

The solution provided by the integral theorem for a monochromatic source is:

Second, it is preferred to use a monochromatic or temporally coherent light source.

It remains highly suitable for use with instruments operating using near monochromatic light sources e.g. polarimeters.

Temporal coherence tells us how monochromatic a source is.

Modal dispersion occurs even with an ideal, monochromatic light source.

Fig. 2 shows use of a monochromatic source.

It is important to have monochromatic source of radiation for analysis of the sample.

Stars are not monochromatic sources that one can get an accurate "Doppler shift" from.

However, this requires a bright and highly monochromatic light source to be effective.