In modern high-intensity ultrafast laser processing, detecting the focal position of the working laser beam, at which the intensity is the highest and the beam diameter is the lowest, and immediately locating the target sample at that point are challenging tasks. A system that allows in-situ real-time focus determination and fabrication using a high-power laser has been in high demand among bot...

Welding with laser beams is an innovative technique, which is leads to higher penetration depth and a narrower seam compared to conventional welding techniques. One significant criterion of the quality of a junction is the penetration depth. Within this article a predictive control scheme is presented that optimises the process input laser power by taking the future welding speed into account. ...

A new accelerator LACARA is under construction at ATF, Brookhaven National Laboratory. LACARA is to be powered by a 1 TW CO2 laser, and will utilize a 6-T 2-m long solenoidal magnetic field. For a 50 MeV injected electron bunch, LACARA is expected to produce a 100 MeV 1 ps gyrating beam with ~ 3% energy spread. Beam electrons advance in phase at the laser frequency, executing one cycle each 35 ...

In contrast to numerical methods for beam shaping, analytical beam shaping consists of two steps: rst, nding a purely geometrical distortion between the input and output plane redistributing the intensity of the incoming wavefront and second, computing a phase-only element realizing this coordinate transform. For the latter the method of stationary phase may be applied. The known classes of pos...

This study proposes a newly developed optimization method for an aspherical lens system employed in a refractive laser beam shaping system, which performs transformations on laser spots such that they are transformed into flat-tops of any size. In this paper, a genetic algorithm (GA) with multipoint search is proposed as the optimization method, together with macro language in optical simulatio...

The capability to produce laser pulses of arbitrary temporal shape is important in areas of optical communication,' atomic and molecular spectroscopy~ and laserfu~ion.~ Previous pulse-shaping techniques have achievedmoderate success in these areas.44 The new approach discussed here, using the technique of spectral beam deflection (SBD), offers the potential of higher temporal resolution combine...

High performance TeV energy electron / positron colliders (LC) are the first machines to require online, non-invasive beam size monitors for micron and submicron for beam phase space optimization. Typical beam densities in the LC are well beyond the threshold density for single pulse melting and vaporization of any material, making conventional wire scanners ineffective. Using a finely focused,...

The actual market volume of high-power lasers for manufacturing is dominated by diffusion cooled CO2 laser systems at the multi-kW range and lamp pumped Nd:YAG laser systems at the kW range. Substituting the lamps by diodes the Nd:YAG laser in rod design entered the market as diode pumped solid state laser of the first generation. With output powers up to 6 kW the diode pumped rod is used in in...