physicists, Vasov and Prokorov. Towns wrote his autobiography from the invention
of the laser to finding of maser from the universe. The observed maser by radio
telescope is the emission from the cloud of water molecules far in space, and the
molecules are continuously excited by the photons from an ambient star [5]. The
early work that finally led to the invention of maser and laser was the research to
develop the radiation source for the radar during WWII. Although they thought that
laser would be possible from excited gas, Maiman has realized the first laser using
ruby rod pumped by flash lump as shown in Fig. 1.3 [6].
The peak power of lasers in the unit of watt (W) has increased as shown in
Fig. 1.4. Maiman’s first laser was only 100 W; however, it increased exponentially
by subsequent technology innovations, namely, Q-switching and mode locking.
Metal-doped glass laser has been developed as better amplifier for high-power
laser in 1961, and a single pulse extraction was demonstrated in 1968 with 50 GW
at 1 ns pulse (50 J). Since the breakdown of the glass amplifiers limits the laser
intensity (W/cm
2 ) in the amplification process, the further increase of the power has
Fig. 1.3 (a) Maiman and his ruby laser. (b) The structure of the inside of cylindrical case
1960
1970
1980
1990
2000
2010
2020
Watt
kW
MW
GW
TW
PW
EW
Laser peak power
year
Invention
of CPA
First laser
Mode-lock
Gekko
Q-switch
NOVA
Novett
ELI
NIF
Intense laser
Ultra-intense laser
Fig. 1.4 Historical
evolution of output power of
high-power laser for laser
fusion research. The NOVA
laser is converted to ultraintense laser after the usage
of NOVA for laser fusion
research. NIF is the world’s
biggest laser constructed for
laser fusion ignition
4
1 Introduction
of the laser to finding of maser from the universe. The observed maser by radio
telescope is the emission from the cloud of water molecules far in space, and the
molecules are continuously excited by the photons from an ambient star [5]. The
early work that finally led to the invention of maser and laser was the research to
develop the radiation source for the radar during WWII. Although they thought that
laser would be possible from excited gas, Maiman has realized the first laser using
ruby rod pumped by flash lump as shown in Fig. 1.3 [6].
The peak power of lasers in the unit of watt (W) has increased as shown in
Fig. 1.4. Maiman’s first laser was only 100 W; however, it increased exponentially
by subsequent technology innovations, namely, Q-switching and mode locking.
Metal-doped glass laser has been developed as better amplifier for high-power
laser in 1961, and a single pulse extraction was demonstrated in 1968 with 50 GW
at 1 ns pulse (50 J). Since the breakdown of the glass amplifiers limits the laser
intensity (W/cm
2 ) in the amplification process, the further increase of the power has
Fig. 1.3 (a) Maiman and his ruby laser. (b) The structure of the inside of cylindrical case
1960
1970
1980
1990
2000
2010
2020
Watt
kW
MW
GW
TW
PW
EW
Laser peak power
year
Invention
of CPA
First laser
Mode-lock
Gekko
Q-switch
NOVA
Novett
ELI
NIF
Intense laser
Ultra-intense laser
Fig. 1.4 Historical
evolution of output power of
high-power laser for laser
fusion research. The NOVA
laser is converted to ultraintense laser after the usage
of NOVA for laser fusion
research. NIF is the world’s
biggest laser constructed for
laser fusion ignition
4
1 Introduction