366 Ultrashort Sources II: Examples
their poor thermal conductivity, makes these crystals unsuitable for high power
applications. Cr:LiCAF is preferred to the other two in applications such as
regenerative amplifiers, because of its slightly larger saturation energy and better
tolerance to a temperature increase.
The Cr
3+
:LiSrAlF
6
is the most popular laser medium for low power, high
efficiency operation. It is generally pumped by high brightness AlGaInP laser
diodes. The emitting cross section of a typical laser diode is rectangular, with a
thickness of only a few micron, and a width equal to that of the diode. A “high
brightness” diode is one for which the width does not exceed 200 µm. The
shorter the diode stripe, the higher the brightness, and the