Page 201 - Tunable Lasers Handbook

5 Dye Lasers 179

TABLE 5 Laser-Pumped Oscillator-Amplifiersa

Number of
amplifica-
tion Total Output Average
Oscillator stages gain A\! energj power 9% Efficiency Reference

Littrow grating Oneh 10-100 -2.4 GHz 0.25 mT 25 at 160 nm [59]
and two etalons
Telescope and Three 229 320MHz 165mJ 55 at 590 nm [SO]
Littrow grating
plus etalon
HMPGI Two -700 650MHz 3.5 mJ -9 at 440 2rn [SI]
MPL plus etalon Four( d 0.05-5 GHz >1.3 kW >50 PI
3Adapted from Duarte [37], with permission.
Qscillator and amplifier synchronously pumped by two N2 lasers.
.These results correspond to a single MOPA chain of the system.
Srhis system uses double-transverse excitation of the amplifier stages.

In addition to the dispersive oscillators listed on Table 6 some authors have
also used cw or quasi-cw lasers as injection sources [64,65].

3. FLASHLAMP-PUMPED DYE LASERS

This section is intended to be an expeditious guide to the performance of
flashlamp-pumped dye lasers. For a detailed and thorough review on this subject
the reader is referred to the work of Everett [19].

3.1 Excitation Configurations
Flashlamp-pumped dye lasers can be excited using linear, coaxial, and
transverse configurations. Linear and coaxial excitation configurations are illus-
trated in Fig. 6. Linear flashlamp pumping utilizes two or more flashlamps
deployed symmetrically around the active region (Fig. 6a). The aim here is to
provide concentric illumination of the dye region and thus obtain a uniform
beam profile. In this regard. high-energy linear pumping arrangements can
involve up to 18 or more lamps.
Coaxial flashlamp excitation provides uniform and inherently concentric
oprical pumping of the dye region (Fig. 6b). In both methods of excitation the
dye is illuminated through the cooling fluid and an outer reflector surrounds the
flashlamp(s) (Fig. 6).
Other c'ommon features of coaxial and linear excitation include a linear dye
flow, along the optical axis. and the use of relatively low dye concentrations