EFFICIENT FREQUENCY DOUBLING OF A CONTINUOUS-WAVE TITANIUM - SAPPHIRE LASER IN AN EXTERNAL ENHANCEMENT CAVITY

A Ti:sapphire ring laser capable of providing 1.4 W of single mode output at 800 mn with 10 W of Ar+ pump power is developed. The short term frequency stability of order 2 kHz is assured with an external cavity to which the laser is locked using an FM sideband method. The long term stability is assured with a second, very stable cavity and is of order of +/- 5 kHz. Thanks to efficient second harmonic generation, we have extended the spectral range of the laser to the violet region. For an incident fundamental power at 820 nm of 1.9 W, we have obtained as much as 410 mW of light at 410 nm using a LBO crystal placed in an external resonator.