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We designed and characterized a 3D printed acoustic shear wave polarization rotator (PR) based on the specific nature of the fused-deposition-modeling printing process. The principle of the PR is based on rotation of the polarization axis of a shear wave due to the gradual change in orientation of the axis of anisotropy along the direction of wave propagation of a printed layered structure. The component of the shear modulus parallel to the infilled lines within each layer is significantly higher than that in the perpendicular direction. As the PR was printing, a small angle between neighboring layers was introduced, resulting in a 3D helicoidal pattern of distribution of the axes of anisotropy. The polarization of the propagating shear wave follows this pattern leading to the rotation of the polarization axis by a desirable angle. The total rotation angle can be tuned by the number of printed layers. The fabricated [Formula: see text] rotators demonstrate high performance that can be improved by changing the infill fraction settings.
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Polarization-Controlled Microchannel Arrays Induced by Femtosecond Laser Pulses
Using pulsed femtosecond laser irradiation, we demonstrate the creation of an array of microgrooves within a single laser spot on metals. The orientation of these grooves is not limited to being parallel to the plane of the laser beam’s propagation but can orient at any angle up to 30 degree from parallel. We control the orientation of the microgrooves by proportionally varying the laser’s polarization. Polarization, angle of incidence, and structural evolution dynamics have been thoroughly studied to help us understand this phenomenon. Our studies suggest that the formation of angled microgroove arrays is due to a feedback effect occurring between defect-focused ablation and polarization-dependent laser-induced periodic surface structures.
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- Award ID(s):
- 1701163
- PAR ID:
- 10060357
- Date Published:
- Journal Name:
- Journal of applied physics
- Volume:
- 123
- ISSN:
- 1520-8850
- Page Range / eLocation ID:
- 213103
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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