
Problems 57
is equivalent to τ
G0
= w
0
r/(Lc). For r = w with w ≈ Lλ/(πw), cf. Eq. (1.182),
the pulse duration becomes τ
G0
≈ λ/(πc). Obviously, these effects become only
important if the pulses approach the single-cycle regime.
1.8. PROBLEMS
1. Verify the c
B
factors of the pulse duration–bandwidth product of a Gaussian
and sech pulse as given in Table 1.1.
2. Calculate the pulse duration ¯τ
p
defined as the second moment in Eq. (1.49)
for a Gaussian pulse and compare with τ
p
(FWHM).
3. Consider a medium consisting of particles that can be described by
harmonic oscillators so that the linear susceptibility in the vicinity of a
resonance is given by Eq. (1.153). ...