摘要
A Ti：sapphire crystal with a diameter of 235 mm and thickness of 72 mm was grown by the heat exchange method（HEM）. The absorption intensity of the crystal at 532 nm averaged at 91%. The figures of merit（FOMs）at different positions of the crystal were measured and the FOM value in the central region was found to reach 90.The transmittance laser beam was intact with no obvious distortions and had only a small deformation compared with the incident laser beam. A small-signal amplification experiment was performed on the Ti：sapphire crystal and a gain of more than 6 times was achieved with a pump energy density of 1.98 J∕cm^2. These tests indicate that the 235 mm Ti：sapphire crystal has excellent optical qualities and will further improve the energy output of a 10 PW laser system.
A Ti：sapphire crystal with a diameter of 235 mm and thickness of 72 mm was grown by the heat exchange method（HEM）. The absorption intensity of the crystal at 532 nm averaged at 91%. The figures of merit（FOMs）at different positions of the crystal were measured and the FOM value in the central region was found to reach 90.The transmittance laser beam was intact with no obvious distortions and had only a small deformation compared with the incident laser beam. A small-signal amplification experiment was performed on the Ti：sapphire crystal and a gain of more than 6 times was achieved with a pump energy density of 1.98 J∕cm^2. These tests indicate that the 235 mm Ti：sapphire crystal has excellent optical qualities and will further improve the energy output of a 10 PW laser system.
基金
supported by the National Natural Science Foundation of China(Nos.61775223 and 51502321)
the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB1603)
the Shanghai Scientific Research Project(Nos.16JC1420600 and 16DZ0503900)
