Pulse compression and beam focusing with segmented diffraction gratings in a high-power chirped-pulse amplification glass laser system.
Segmented (tiled) grating arrays are being intensively investigated for petawatt-scale pulse compression due to the expense and technical challenges of fabricating monolithic diffraction gratings with apertures of over 1m. However, the considerable freedom of motion among grating segments complicates compression and laser focusing. We constructed a real compressor system using a segmented grating for an 18cm aperture laser beam of the Gekko MII 100TW laser system at Osaka University. To produce clean pulse shapes and single focal spots tolerant of misalignment and groove density difference of grating tiles, we applied a new compressor scheme with image rotation in which each beam segment samples each grating segment but from opposite sides. In high-energy shots of up to 50J, we demonstrated nearly Fourier-transform-limited pulse compression (0.5ps) with an almost diffraction-limited spot size (20microm).
Institute of Laser Engineering, Osaka University, 2-6, Yamada-oka, Suita, Osaka 565-0871, Japan. habara@ile.osaka-u.ac.jp
Hideaki
H
Habara
Guang
G
Xu
Takahisa
T
Jitsuno
Ryosuke
R
Kodama
Kenji
K
Suzuki
Kiyonobu
K
Sawai
Kiminori
K
Kondo
Noriaki
N
Miyanaga
Kazuo A
KA
Tanaka
Kunioki
K
Mima
Michael C
MC
Rushford
Jerald A
JA
Britten
Christopher P J
CP
Barty