Abstract

The average power output from a Nd:glass slab laser is limited by thermal stress fracture because of the low thermal conductivity of glass. The moving slab laser concept increases the average output power much beyond the limit of the static slab lasers. In the moving slab laser the average thermal power is dissipated over the area of the slab while the gain is concentrated in a small region. The result is a gain enhancement and average power scaling of the area of the slab. In our first design we used a Brewster angle cut, zigzag path rectilinear slab of LHG-5 glass, 16.7 × 15 × 0.44 cm, which moved back and forth between two 4-mm diam krypton lamps and metal cooling plates by means of a computer-controlled linear motor. Static helium gas was used to thermally couple the glass to the cooling plates. At the limit of our power supply we obtained 43.8 W of average laser at 276 J/pulse and at 10-Hz repetition rate. At 30-Hz repetition rate and at 32 J/pulse the laser output was 13.5 W. The moving slab Nd:glass laser is in the process of scaling up to 300-W and 1-kW average power levels in two states of development.

© 1986 Optical Society of America