Rami Arieli: "The
Laser Adventure" Chapter 5 Section 1, page 4
Mathematical Expressions of fluorescence
linewidth
Fluorescence linewidth
is expressed by wavelengths, or frequencies, of two points on the spontaneous
emission graph at half the maximum
height.
The linewidth (D l)
is much smaller than each of the wavelengths (Dl<<l1,l2).
Thus the approximation: l1*l2
= l02 can be
used.
l0 = Wavelength at the
center of emission spectrum of the laser.
The result is:
In a similar way:
In chapter 10 these
mathematical relations will be used for determining the coherence
of the laser.