Laser materials processing has been widely investigated as a promising technology to develop and fabricate advanced structured materials on a nano or micro scale. Optical vortex, i.e. helical light, carries an annular intensity profile and orbital angular momentum arising from its helical wavefront, and it induces the wavefront-sensitive mass transport (so-called optical angular momentum transfer effects) with the help of the spin angular momentum associated with the circular polarization.
Recently, we and our coworkers discovered that laser materials processing based on optical vortex illumination enables us to establish chiral structures in various materials, such as a metal, a silicon and an azo-polymer owing to the wavefront-sensitive mass transport effects.
Such chiral structures will pave a pathway towards new optical devices, including chiral plasmonic metasurfaces for screening, collecting and identifying the chiral chemical composites at high accuracy and high sensitivity. They might also act as advanced functional materials such as water repellent finished surfaces as well as perfect absorbers.
In this presentation, we review state-of-the-art chiral structures formed by optical vortex illumination, and we also detail the direct observation of the chiral structures formation by utilizing an ultrahigh speed camera. Further, we address a theoretical analysis of the optical radiation force induced by optical vortex illumination.
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