Rami Arieli: "The Laser Adventure"

Rami Arieli: "The Laser Adventure" Chapter 1.2 page 2

The Meaning of "One Color"
In the theoretical sense "One Color",which is called "spectral line",meansone wavelength (l₀).
A graph of light intensity versus wavelength for ideal "one color" is shown on the right side of figure 1.7.
The right side of figure 1.7 shows an artistic description of realistic "one color". It has a peak of its value of "the color", but include a spread around the central peak. In reality, every spectral line has a finite spectral width (Dl) around its central wavelength (l₀), as can be seen in the left side of figure 1.7.

Figure 1.7: Bandwidth of laser radiation in Theory and in Reality

(If you would like to get a feeling about orders of magnitudes, Click Here⁽⁵⁾)