Lawrence Livermore National Laboratory
Tailored-Aperture Ceramic Laser
To improve the run time and beam quality of large, high-average-power (HAP), diode-pumped solid-sate laser (DPSSL) systems, PS&A has developed a new slab laser technology called the tailored-aperture ceramic laser (TACL). A higher-performance descendent of the solid-state heat-capacity Laser (SSHCL) system, TACL uses composite ceramic Nd3+:YAG/Sm3+:YAG slabs that are edge pumped.
Edge pumping is made possible by use of a ceramic Sm3+:YAG frame that is integral to the Nd3+:YAG portion of the slab. Sm3+:YAG absorbs at the laser wavelength, but is transparent at the pump wavelength. The Sm3+:YAG frame suppresses amplified spontaneous emission without affecting passage of the pump light. This recent development proceeds from the concerted work of LLNL and the Konoshima Chemical Company and promises to revolutionize the design of large HAP laser systems by significantly improving beam quality.
By smoothing the high spatial frequency pump-deposition ripples that result from face pumping, edge pumping can improve system beam quality and runtime considerably. New diode-pump arrays are also employed in TACL that use high-performance microlens conditioning and microchannel cooling. The microchannel cooling of the arrays allows the diode packages to be run with a high duty cycle – even continuously – while generating high average optical pump power. As a result, TACL designs can use as little as one-tenth of the diode arrays employed by the SSHCL system while achieving the same power output capability.
