Page 298 - High Power Laser Handbook

CHAPTER 11

Heat-Capacity Lasers

Robert M. Yamamoto
Principal Investigator, Lawrence Livermore National Laboratory,
Livermore, California

Mark D. Rotter
Member of the Technical Staff, Lawrence Livermore National
Laboratory, Livermore, California

11.1 Introduction
Over the past decade, scientists and engineers have actively engaged
in developing the key technologies required to realize the perfor-
mance potential of the heat-capacity laser (HCL). Several scientific
institutions around the world, most notably the Chinese Academy of
2
1
Sciences in Beijing and Shanghai and the Lawrence Livermore
National Laboratory (LLNL) in California, have been developers of
3
this type of solid-state laser architecture. The fundamental feature of
the heat-capacity laser that makes it unique from other solid-state
lasers is the distinct separation of the lasing action from the cooling
required of the laser gain media. Heat is stored in the laser gain media
during the lasing process and is then cooled off-line, away from the
laser beam line. This allows aggressive cooling methods of the laser
gain media to be realized, because the cooling does not interfere with,
and is independent of, the lasing process.

11.2 System Architecture

An important attribute of the HCL is that it lends itself to an extremely
simple design of the laser cavity, utilizing a single-aperture architec-
ture comprised of large laser gain media (slabs) pumped by arrays of
high-power diode bars. Figure 11.1 shows the latest configuration of
the heat-capacity laser used at LLNL. 4

267