CC BY
7The 30th International Conference on Advanced Laser Technologies
ALT'23
LM-O-3
Advanced optical manipulation with structured laser beams
A. Porfirev1'2, S. Khonina1'2, D. Porfirev1'2, S. Karpeev1'2
1- Samara National Research University, Samara, Russia
2- Image Processing Systems Institute ofRAS—Branch of the FSRC "Crystallography and Photonics " RAS, Samara,
Russia
porfirev. [email protected]
Now structured laser beams with predetermined intensity, phase, and/or polarization distributions are widely used for implementation of holographic optical tweezers (HOTs) - modifications of the conventional optical tweezers, for the invention of which Ashkin was awarded the Nobel Prize in Physics in 2018. The OT is an all-optical technology that allows one to three-dimensionally confine and guide nano- and microscale objects trapped at the focus of a laser Gaussian beam. HOTs made it possible to shape complex optical traps and allow one not only to carry out parallel trapping of a set of micro-objects [1] but also to carry out such types of optical non-contact manipulation as the rotation of micro-objects [2], moving them along the desired complex three-dimensional trajectories [3], as well as moving along linear trajectories in the direction of the laser source, i.e. allow realizing simple forms of pulling(tractor) laser beams [4]. It is the inhomogeneous structure of the intensity, phase, or polarization of such optical traps that makes it possible to carry out such types of manipulation.
Here, we proposed new techniques for shaping of structured laser beams with the desired two and three-dimensional structure of the intensity distribution. The techniques are based on the use of classical and diffractive optical elements. The shaped multiple optical traps, polygon laser beams, and clusters of rotating beams with autofocusing and transformation properties were used for demonstration of simultaneous trapping of multiple (up to a thousand) light-absorbing particles in air (see Figs. 1 and 2). The trapping of such particles is possible due to the so-called photophoretic (PP) forces pushing the trapped strongly absorbing particles away from areas of relatively high intensity [5]. The demonstrated HOTs do not require an active control of location or orientation of the generated optical traps for implementation of multiple laser trapping and guiding of the particles. Only a control of the initial power of the laser source generating optical traps is used in some cases. The proposed HOTs can be used for solving of the problem of passive all-optical sorting of airborne particles and their guiding along curvilinear trajectories. This work was supported by the Russian Science Foundation grant No. 22-12-00041.
Figure 1. Laser trapping of multiple light-absorbing particles in air with a polygonal laser beam.
Cjf » V A c j c" c " w
61 X 1?' \ V s
Figure 2. Laser guiding of a light-absorbing particle in air with a rotating laser beam: (a) transverse intensity distributions of the beam, (b) motion stages of the guided particle, (c) particle trajectory.
[1] D. G. Grier, A revolution in optical manipulation, Nature, vol. 424, pp. 810-816 (2003).
[2] M. Padgett, R. Bowman, Tweezers with a twist, Nat. Photonics, vol. 5, pp. 343 (2011).
[3] J.A. Rodrigo and T. Alieva, Freestyle 3D laser traps: tools for studying light-driven particle dynamics and beyond, Optica, vol. 2, pp. 812-815 (2015).
[4] S. Sukhov and A. Dogariu, Negative nonconservative forces: optical "tractor beams" for arbitrary objects, Phys. Rev. Lett., vol. 107, pp. 203602 (2011).
[5] H. Horvath, "Photophoresis-a forgotten force?" KONA Powder Part. J., vol. 31, pp. 181-199 (2014).
