Spin to orbital light momentum conversion visualized by particle trajectory
Por:
Arzola, Alejandro V., Chvatal, Lukas, Jakl, Petr, Zemanek, Pavel
Publicada:
11 mar 2019
Categoría:
Multidisciplinary
Resumen:
In a tightly focused beam of light having both spin and orbital angular
momentum, the beam exhibits the spin-orbit interaction phenomenon. We
demonstrate here that this interaction gives rise to series of subtle,
but observable, effects on the dynamics of a dielectric microsphere
trapped in such a beam. In our setup, we control the strength of
spin-orbit interaction with the width, polarization and vorticity of the
beam and record how these parameters influence radius and orbiting
frequency of the same single orbiting particle pushed by the laser beam.
Using Richard and Wolf model of the non-paraxial beam focusing, we found
a very good agreement between the experimental results and the
theoretical model based on calculation of the optical forces using the
generalized Lorenz-Mie theory extended to a non-paraxial vortex beam.
Especially the radius of the particle orbit seems to be a promising
parameter characterizing the spin to orbital momentum conversion
independently on the trapping beam power.
Filiaciones:
Arzola, Alejandro V.:
Instituto de Física, Universidad Nacional Autónoma de México, Apartado Postal 20-364, Ciudad de México, 01000, Mexico
Univ Nacl Autonoma Mexico, Inst Fis, Apartado Postal 20-364, Mexico City 01000, DF, Mexico
Chvatal, Lukas:
Institute of Scientific Instruments of the Czech Academy of Sciences, Královopolská 147, Brno, 612 64, Czech Republic
Czech Acad Sci, Inst Sci Instruments, Kralovopolska 147, Brno 61264, Czech Republic
Jakl, Petr:
Institute of Scientific Instruments of the Czech Academy of Sciences, Královopolská 147, Brno, 612 64, Czech Republic
Czech Acad Sci, Inst Sci Instruments, Kralovopolska 147, Brno 61264, Czech Republic
Zemanek, Pavel:
Institute of Scientific Instruments of the Czech Academy of Sciences, Královopolská 147, Brno, 612 64, Czech Republic
Czech Acad Sci, Inst Sci Instruments, Kralovopolska 147, Brno 61264, Czech Republic
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