<title>Laser beam shaping by holographic optical elements</title>

Abstract

For material processing and laser machining, it is important to shape intensity and phase profiles of the laser beams. For dynamic beam shaping, we suggest the method based on energy exchange during self-diffraction of laser beams in the photorefractive materials. For applications, related to use of the powerful lasers we have tested a possibility of beam shaping by holographic optical elements, recorded in Photo-Thermo-Refractive (PTR) glasses, developed in CREOL. The gratings in PTR glasses are stable up to 400°C with laser-induced breakdown energy threshold of 10 J/cm² in 1 ns pulses at 1064 nm. High diffraction efficiency more than 95% of gratings recorded in PTR glass allows to achieving high energy transfer that is vital for commercial laser applications. Preliminary results show that flattop distribution of laser intensity may be realized in the diffraction orders.