The experimental performance of beam smoothing by combined one-dimensional(1D) spectral dispersion and lens array(LA) technology is presented,as applied in the ninth beam of SG-II.Using 3ω spectral dispersion with a ...The experimental performance of beam smoothing by combined one-dimensional(1D) spectral dispersion and lens array(LA) technology is presented,as applied in the ninth beam of SG-II.Using 3ω spectral dispersion with a bandwidth of 270 GHz and a line dispersion that is 24.9 times the beam's diffractionlimited width decreases the focal spot non-uniformity of 80% energy concentration from 46% to 17%.The multiple-beam interference properties of the LA are theoretically and experimentally validated by spatial power spectral density analysis.Peak-spectra suppression ratios of 20 and 10 dB are achieved in the dispersion and orthogonal directions,respectively.展开更多
In order to avoid stimulated Brillouin scattering and smooth the final focal spot that reaches the D-T capsule, spectral broadening is essential. However, the modulation of spectral structure might result in frequency...In order to avoid stimulated Brillouin scattering and smooth the final focal spot that reaches the D-T capsule, spectral broadening is essential. However, the modulation of spectral structure might result in frequency-to-amplitude modulation (FM-to-AM) conversion. The spatial filter pinhole is used to cut off the high-frequency transmission laser, and to ensure the desired pass. Improper parameter of pinhole would lead a negative impact. Using the spatial filter pinhole, we analyze the characteristic of intensity modulation using several pinholes of improper parameters. We then compare these results with the intensity modulation obtained from an experiment. Experimental diagnosis and design of an appropriate pinhole parameter would be highly beneficial to the field of high-power lasers.展开更多
基金supported by the National "863" Project of Chinathe National Natural Science Foundation of China(No.11204043)
文摘The experimental performance of beam smoothing by combined one-dimensional(1D) spectral dispersion and lens array(LA) technology is presented,as applied in the ninth beam of SG-II.Using 3ω spectral dispersion with a bandwidth of 270 GHz and a line dispersion that is 24.9 times the beam's diffractionlimited width decreases the focal spot non-uniformity of 80% energy concentration from 46% to 17%.The multiple-beam interference properties of the LA are theoretically and experimentally validated by spatial power spectral density analysis.Peak-spectra suppression ratios of 20 and 10 dB are achieved in the dispersion and orthogonal directions,respectively.
文摘In order to avoid stimulated Brillouin scattering and smooth the final focal spot that reaches the D-T capsule, spectral broadening is essential. However, the modulation of spectral structure might result in frequency-to-amplitude modulation (FM-to-AM) conversion. The spatial filter pinhole is used to cut off the high-frequency transmission laser, and to ensure the desired pass. Improper parameter of pinhole would lead a negative impact. Using the spatial filter pinhole, we analyze the characteristic of intensity modulation using several pinholes of improper parameters. We then compare these results with the intensity modulation obtained from an experiment. Experimental diagnosis and design of an appropriate pinhole parameter would be highly beneficial to the field of high-power lasers.
