Observation of vacuum-ultraviolet Ar2* radiation gain at 126 nm produced by an ultrashort high-intensity laser pulse propagating in a hollow fiber.
We observed a small-signal gain of Ar2* emission at 126 nm by use of a hollow fiber to guide the high-intensity laser propagation in high-pressure Ar. The small-signal gain coefficient was measured to be 0.05 cm(-1) at 126 nm. Kinetic analysis revealed that the electrons produced by the high-intensity laser through an optical-field-induced ionization process initiated the Ar2* production processes. The increase in the emission intensity was measured to be exp(2.5), with an increase in the fiber length.
Kaku
Masanori
M
Department of Electrical and Electronic Engineering, Photon Science Center, Miyazaki University, Gakuen Kibanadai Nishi 1-1, Miyazaki 889-2192, Japan.
Higashiguchi
Takeshi
T
Kubodera
Shoichi
S
Sasaki
Wataru
W