<title>Laser beam shaping via conventional design software</title>

Abstract

Previous efforts have shown that optimization-based techniques, particularly genetic algorithms, can be used to effectively design beam shaping systems for several classes of problems. These techniques have used external programs to perform the optimization, which allow a great deal of optimization flexibility. However, the external program must be understood and tuned for beam shaping applications. For many problems, the flexibility of an external program is not required. This work shows that the internal optimization routines in a typical lens design program can perform effective optimization of several classes of beam shaping systems. In addition, previous beam shaping merit functions have used a large number of rays, typically 200, to perform the optimization. Several pieces of data must be recorded for each ray. This results in a fairly lengthy merit function evaluation by the lens design program. This work shows that by setting up certain problems using upfront geometrical considerations, reasonable optimizations can be obtained with as few as 20-40 rays being traced. Example problems are presented, including the merit functions used. Guidance is provided for the designer interested in picking appropriate parameters and optimization routines for some typical problems.

Illumination optimization: The revolution has begun

“…If the source is assumed to be a point source, then the relationship between angles at the source and positions at the target can be computed using energy balance relationships {e.g., 6,7]. This approach can provide a robust merit function; however, it does not provide a direct measure of the illuminance.…”

Track geometry in selective laser melting

“…Keywords: additive technology, selective laser melting, laser modulation, CoCrMo powder DOI: 10.3103/S1068798X15060143 The creation of a spot with a uniform power den sity distribution in the focal plane was considered in [17,18]. By means of inverse Fourier transformations, it was shown that an input beam with an Airy disk dis tribution is required to obtain a uniform power den sity distribution in the focal plane of the lens.…”