In our diamond-cooled approach, thin disks of laser gain material, e.g., Nd:YAG, are alternated between thin disks of single crystal synthetic diamond whose heat conductivity is over 2000 W/m-°K. The gain medium is face-pumped (along the optical axis) by the output of laser diode arrays. This optical configuration produces heat transfer from Nd:YAG to the diamond, in the direction of the optical axis, and then heat is rapidly conducted radially outward through the diamond to the cooling fluid circulating at the circumference of the diamond/YAG assembly. This geometry effectively removes the heat from the gain material in a manner that permits the attainment of high power output with excellent beam quality.
Scaling studies of a Cr:LiSAF power oscillator are being performed and 80W average output power has been achieved at 10Hz repetition rate using a newly designed transverse flow cell. An SBS phase conjugate system using Fluorinert FC-75 has been set up and reflectivity measurements indicate very good fidelity with reflectivities >60%, at pulse energies of less than 1J.