Page 54 - Tunable Lasers Handbook

3 Tunable Excimer lasers 35

TABLE 2 Narrow-Linewidth Gas Laser Oscillatorsa

Laser Cavity A (nm) Av Eo Reference
ArF MPL 193 10 GHz 150 pJ
KrF GI 218 59 GHz 15 pJ
X?Cl GIh 308 -31 GHz 50 mT
XeCl GE' 308 -1.5 GHz -1 mT
XeCl GI 308 -1 GHz 3mT
XeCl 3 etalons 308 5150 MHz 2-5 pJ
XeF MGId 35 1 -40 MHz -0.1 pJ
CO, GIh 10,591 117 MHz 140 mT
CO, GIh 10,591 100-700 MHz 230 mJ
CO, MPL 10.591 5130 MHz 200 mJ
C02 HMPGP 10.591 107 MHz 85 mT

3From Dume [l?].
"pen-cavity configuration.
'Incorporates Michelson interferometer.
dhhltipass grating interferometer.
eHybrid multiple-prism grazing-incidence cavity.

grating configurations were also introduced to pulsed gas lasers [10,11]. In this
regard, note that multiple-prism Littrow (MPL) grating configurations were subse-
quently incorporated in commercially available gas lasers. Table 2 provides a use-
ful summary of different types of cavities available for narrow-linewidth gas laser
oscillators. including excimer lasers, with their respective emission performance.
The performance of some oscillatorlamplifier and master oscillator/forced
oscillator excimer laser systems is summarized in Table 3.
Applications for tunable narrow-linewidth excimer lasers include spec-
troscopy, selective photoionization processes, laser radar. and lidar.
In this chapter first we survey the basic spectroscopic characteristics of
excimer laser emission. and then follow up with a review of tuning methods for
discharge and electron beam pumped excimer lasers. For a historical perspective
on excimer lasers the reader should consult [ 11.

2. EXCIMER ACTIVE MEDIA

Excimers are an important active media for lasers operating in the ultravio-
let and vacuum ultraviolet (VUV) spectral regions.
Although a comprehensive understanding of excimers can involve quite a
complex modeling of kinetic reactions and absorbing species, these molecules do
share some common features. Consequently, a few simple models and concepts