The importance of laser wavelength for driving inertial fusion targets.*

It is well known that the wavelength of the laser determines many of the fundamental parameters of the laser coupling that drive an inertial fusion target. Deposition density, mass ablation rate, absorption fraction, hydrodynamic efficiency, and laser-plasma instability thresholds are all influenced by laser wavelength, with shorter laser wavelength being uniformly favorable. What may be less appreciated is the synergistic effects of decreasing the laser wavelength, and its implications for ICF. We show that ostensibly minor decreases in laser wavelength --- e.g., changing the drive wavelength from the common 351 nm ( frequency-tripled glass laser) to 248 nm (KrF laser) or 193 nm (ArF laser) --- can have much larger effects on the resulting target performance. The increase in usable bandwidth for the shorter wavelength lasers also has a profound impact, decreasing laser imprint and further increasing parametric instability thresholds, and can increase the design space for icf targets even further. We will show simulation results that reinforce these points.