Figure 4.

Divergence measurements for the Chameleon (Coherent, Inc.) Ti:sapphire laser. The divergence measurements were made by comparing 1∕e² beam diameters at 12.5 cm and at 3 m from the laser exit window. At 12.5 cm from the exit port, 1∕e² beam diameters measured from 1.1 to 1.4 mm and increased linearly as a function of wavelength. At 3 m from the exit port, the 1∕e² beam diameter was as large as 5.6 mm at the peak of the power-tuning curve.