High-speed temporal and spatial beam-shaping combining active and passive elements

Abstract

Temporal and spatial shaping of laser beams is common in laser micromachining applications to improve quality and throughput. However, dynamic beam shaping (DBS) of ultrashort, high-power pulses at rates of hundreds of kHz has been challenging. Achieving this allows for full synchronization of the beam shape with high repetition rates, high-power lasers with zero delay time. Such speeds must manipulate the beam shape at a rate that matches the nanosecond to microsecond process dynamics present in laser ablation. In this work, we present a novel design capable of alternating spatial and temporal beam shapes at repetition rates up to 330 kHz for conventional spatial profiles and temporal shaping at nanosecond timescales. Our method utilizes a unique multi-aperture diffractive optical element combined with two acousto-optical deflectors. These high damage threshold elements allow the proposed method to be easily adapted for high power ultrashort lasers at various wavelengths. Moreover, due to the combination of the elements mentioned, no realignment or mechanical movements are required, allowing for high consistency of quality for high throughput applications.

A Review on Laser Beam Shaping Application in Laser‐Powder Bed Fusion

“…[113][114][115][116] Additionally, the combination of spatial and temporal beam shaping could be leveraged to achieve dynamic temporal beam shaping for specific applications. [117] While spatial and temporal beam shaping offer significant benefits, it is important to note that this review focuses solely on continuous wave (CW) laser beam shaping. Therefore, the literature pertaining to temporal beam shaping applications in L-PBF will not be covered here.…”

High-Flexibility Control of Structured Light with Combined Adaptive Optical Systems

“…To overcome the limitations concerning the critical energy fluence on spatial light modulators (SLMs), which causes phase distortions or even material damage, power splitting by using multiple devices was demonstrated [16]. Recently, it was shown that the combination of multi-aperture diffractive-optical elements and acousto-optic deflectors enables one to reach high temporal flexibility with repetition rates up to 330 kHz for conventional beam profiles and shaping on nanosecond scale [17]. Such systems are of particular interest for high-speed and high-power micromachining.…”