The input pulse of the laser PEARL with energy of 18 J and pulse duration of about 60 fs was compressed to 10 fs after passage through a 4-mm-thick KDP crystal and reflection at two chirped mirrors with sum dispersion...The input pulse of the laser PEARL with energy of 18 J and pulse duration of about 60 fs was compressed to 10 fs after passage through a 4-mm-thick KDP crystal and reflection at two chirped mirrors with sum dispersion of-200 fs^(2).The experiments were performed for the B-integral values from 5 to 19 without visible damage to the optical elements,which indicates that small-scale self-focusing is not a significant issue.It was shown that,by virtue of the low dispersion of the group velocity,the KDP crystal has some advantages over silica:a larger pulse compression coefficient,especially at a small value of the B-integral(B=5,...,9),lower absolute values of chirped mirror dispersion,and also a possibility to control the magnitude of nonlinearity and dispersion by changing crystal orientation.展开更多
It was shown experimentally that for a 65-fs 17-J pulse,the effect of filamentation instability,also known as small-scale self-focusing,is much weaker than that predicted by stationary and nonstationary theoretical mo...It was shown experimentally that for a 65-fs 17-J pulse,the effect of filamentation instability,also known as small-scale self-focusing,is much weaker than that predicted by stationary and nonstationary theoretical models for high B-integral values.Although this discrepancy has been left unexplained at the moment,in practice no signs of filamentation may allow a breakthrough in nonlinear pulse post-compression at high laser energy.展开更多
基金supported by the Center of Excellence“Center of Photonics”funded by the Ministry of Science and Higher Education of the Russian Federation,agreement No.075-152020-906by the European Commission,grant agreement#871072-CREMLINplus。
文摘The input pulse of the laser PEARL with energy of 18 J and pulse duration of about 60 fs was compressed to 10 fs after passage through a 4-mm-thick KDP crystal and reflection at two chirped mirrors with sum dispersion of-200 fs^(2).The experiments were performed for the B-integral values from 5 to 19 without visible damage to the optical elements,which indicates that small-scale self-focusing is not a significant issue.It was shown that,by virtue of the low dispersion of the group velocity,the KDP crystal has some advantages over silica:a larger pulse compression coefficient,especially at a small value of the B-integral(B=5,...,9),lower absolute values of chirped mirror dispersion,and also a possibility to control the magnitude of nonlinearity and dispersion by changing crystal orientation.
基金This work was supported by the Ministry of Science and Higher Education of the Russian Federation No.075-15-2020-906(Center of Excellence‘Center of Photonics’).
文摘It was shown experimentally that for a 65-fs 17-J pulse,the effect of filamentation instability,also known as small-scale self-focusing,is much weaker than that predicted by stationary and nonstationary theoretical models for high B-integral values.Although this discrepancy has been left unexplained at the moment,in practice no signs of filamentation may allow a breakthrough in nonlinear pulse post-compression at high laser energy.
