Simulation of mode deflection and reshaping in lithium niobate planar waveguide with serrated array electrodes
In this paper, we establish a lithium niobate (LN) thin film planar waveguide model with serrated array electrode configuration to reshape the optical mode. The refractive index profile of the waveguide can be slightly electro-optically manipulated, so the optical beam can be deflected and reshaped in the transmitted direction of waveguide. When the beam deflection can be modulated via the high speed electro-optic effect of LN, the temporally and spatially beam smoothing can be potentially achieved for the application of inertial confinement fusion system.
Beam smoothing by lens array with spectral dispersion
A scheme of combining technology of lens array (LA) and smoothing by spectral dispersion (SSD) is introduced to improve the irradiation uniformity in laser fusion based on the earlier works on LA. The feasibility of the scheme is also analyzed by numerical simulation. It shows that a focal pattern with flat-top and sharp-edge profile could be obtained, and the irradiation nonuniformity can fall down from 14% with only LA to 3% with both SSD and LA. And this smoothing scheme is depended less on the incidence comparing to other smoothing methods. The preliminary experiment has demonstrated its effectiveness.
Origin and evolution of the optics specifications for the National Ignition Facility
In the second half of the 1990's, LLNL and others will be designing and beginning construction of the National Ignition Facility (NIF). At more than 10 times the power and size of the Nova laser system, this new laser will be capable of producing the worlds first controlled fusion ignition and burn, completing a vital milestone on the path to fusion energy. In order to optimize the performance of the laser system for a minimum cost, we have been conducting a campaign to properly specify the optical properties of the more than 7,500 large optical components to be deployed in the NIF. The draft optics specifications derived from this effort will be presented. The evolution of these specifications, both in language and in content, will be discussed, specifically transmitted wavefront (both P-V and PSD), scratch/dig, surface roughness, bubbles and inclusions specifications.