Page 19 - Tunable Lasers Handbook

2 F. J. Duarte

avenues of differentiation can include the required method of excitation and the
mode of emission, that is, pulsed or continuous wave (cw). Moreover, sources of
tunable coherent radiation can be further differentiated by the spectral region of
emission and energetic and/or power characteristics. Also, in the case of pulsed
emission, pulse duration, and pulse repetition frequency (prf) are important.
The spectral coverage available from pulsed broadly tunable sources of
coherent radiation is listed in Table 1. The spectral coverage available from cw
broadly tunable lasers is given in Table 2 and emission wavelengths available

TABLE 1 Wavelength Coverage Available from Pulsed Broadly Tunable Sources
of Coherent Radiation

Source Wavelength range
Dye lasers 320-1 200 nmo [ 131
Ti3+:A1,03 laser 660-986 nm [ 141
Cr3+:BeAl2O, laser 701-818 nm [I51
OPO
BBO 0.41-2.7 pm [I61
Free-electron lasers (FELs) 2 urn-1 mmb [I71
UWavelength range covered with the use of various dyes.
Kombined wavelength range from several free-electron lasers.

TABLE 2 Wavelength Coverage Available from cw Broadly Tunable Lasers

Laser source Wavelength range
~
Dye lasers 320-1000 rima [18]
Ti3+:AI2O, laser 710-870 nmh [19]
Semiconductor lasersc
InGaAsPDnP 55 nm at 1500 nm [20]
InGaAsPDnP 1255-1335 nm [21]
GaAlAs 815-825 nm [22]
GaAlAs 20 nm at 780 nm [23]
0 Wavelength range covered with the use of various dyes.
bWavelength range of single-longitudinal-mode emission. Tuning range limited by coatings of
mirrors [19]. Commercial designs offer extended tuning ranges beyond 1000 nm.
c Wavelength tuning achieved using external cavity designs.