Ti:sapphire laser cavity mode and pump-laser mode calculations

Comprehensive calculations of the cavity mode size throughout a Ti:sapphire laser, made with the ABCD Gaussian beam formalism are reported. These calculations show that the beam is not collimated, in general, in what are normally referred to as the collimated arms of the laser cavity. Additionally, the mode size and volume (in the gain medium) of the argon-ion laser, which is used to pump the Ti:sapphire laser optically, are evaluated for different focusing geometries, and graphs that can be used to select suitable mode-matching optics are produced. It is concluded that an appropriate strategy for mode matching the pump beam to the Ti:sapphire laser mode is to use a zoom telescope to tailor the collimated pump-laser beam diameter to an optimum value. Finally, comparisons of the pump-laser mode and the Ti:sapphire laser mode are presented for selected pumping geometries.