Polarization maintaining fiber beam delivery for direct laser interference patterning

Microstructured hollow-core fibers enable a flexible integration of high-power ultrafast lasers, offering the advantages of fiber-based beam delivery to ultrafast laser applications. For widespread industrial utilization of this technology, ever-increasing demands need to be fulfilled by adapting the beam delivery to new laser systems and process parameters. We demonstrate, for the first time ever, fiber-based beam delivery of high-power picosecond pulses with high polarization contrast in combination with direct laser interference patterning. By using an ultrashort pulse, high-power, near-infrared laser emitting a fundamental wavelength 1064 nm and pulse energy of 175 μJ at repetition rates up to 500 kHz, an interference pattern with a spatial period of 3.8 μm is produced and applied in stainless steel, illustrating the proof of principle. The fiber-based delivery system represents a versatile tool for 3D microtexturing processes using ultrashort pulse laser systems. The demonstrated results pave the way for high-quality microstructuring of large surface areas by employing fiber-based beam delivery systems.