Rami Arieli: " The
Laser Adventure" Chapter 1.2.3 page 1
1.2.3 Coherence
Since electromagnetic radiation is a wave phenomena, every electromagnetic
wave can be described as a sum (superposition) of sine waves as
a function of time.
From wave theory we know that every wave is described by a wave
function:
y = Acos(wt+f)
A = Amplitude.
w = 2pn = Angular
Frequency.
f = Initial Phase of the wave (Describe
the starting point in time of the oscillation).
(wt+f) = Phase
of the wave.