Use of an intermediate wavelength laser for alignment to inertial confinement fusion targets

摘要

Abstract: The conceptual design of the National Ignition Facility (NIF) 192 beam laser incorporates a low-power alignment beam injected in the pinhole plane of the final spatial filter with a wavelength intermediate between the 1053 nm laser output and the 351 nm frequency- converted beam that illuminates the target. Choosing the specific wavelength for which the spatial filter plane is reimaged in the same target chamber plane as the frequency-converted main laser pulse, achieves optimum accuracy without the need for additional means to insure precise overlap between the two beams. Insertion of the alignment beam after the last laser amplifier also allows alignment to the target while the amplifiers are still cooling from a previous shot. !3