Page 68 - Tunable Lasers Handbook

3 Tunable Excimer lasers 49

persive cavity. A more complete analysis would require a Fox and Li [66] type
calculation of different gain conditions to obtain a full picture of line narrowing
versus the number of round-trips in the cavity.

a
INCREASING NUMBER
OF ROUND-TRIPS
i -x

b

OUTGOING WAVE INCOMING WAVE
AFTER APERTURE BEFORE APERTURE
1st ROUND-TRIP nth ROUND-TRIP
FIGURE 1 1 Schematics of (a) Case a and (b) Case b (from Sze et aZ. [l5]).

1.0
r
I- - UNIFORM BEAM CASE a
g 0.8 -- - UNIFORM BEAM CASE b
w
1
-I Q6
0
w
N 0.4
A
a
I
a 0.2
0
2
0
0 5 IO 15 20 25
N
FIGURE 12 Normalized linewidth as a function of round-cavity trips for (a) Case a and (b)
Case b under uniform illumination conditions (from Sze et al. 1151).