Optical torque on a Rayleigh particle by photonic jet

We study the rotational motion of objects trapped in a focused laser beam (optical tweezers). Micrometer-sized flat slabs are fabricated using two-photon photopolymerization. These objects, trapped by linearly-polarized light, tend to align parallel to the polarization plane. This alignment effect is attributed to the polarization anisotropy resulting from the object shape and we present a simple electromagnetic approach to estimate the resulting optical torque. Micro-rotors of different sizes are studied experimentally. We characterize the behavior of micro-objects when the light polarization is rotated at constant speed. Our theoretical approach gives a good prediction of how the size of micro-objects affects their rotation efficiency.

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Validierung einer optischen Drehmomentmessung*/Validation of an optical torque measurement

wt Werkstattstechnik online ◽

10.37544/1436-4980-2017-09-28 ◽

2017 ◽

Vol 107 (09) ◽

pp. 590-593

Author(s):

T. Schneider ◽

J. Wortmann ◽

B. Eilert ◽

M. Stonis ◽

L. Prof. Overmeyer

Keyword(s):

Measurement Method ◽

Rotation Angle ◽

State Of The Art ◽

Torque Sensor ◽

Torque Measurement ◽

Research Project ◽

Industrial Sectors ◽

Current State ◽

Stand Der Technik ◽

Optical Torque

Das Erfassen von Drehmomenten durch Sensoren sowie das Erzeugen von Drehmomenten stellen eine wichtige Basis für viele Industriezweige dar. Im Rahmen eines Forschungsprojektes wurde ein optisches, berührungsloses Messverfahren zur absoluten Drehwinkel- und Drehmomentmessung entwickelt. Zum Vergleich mit dem aktuellen Stand der Technik wurde ein Versuchsstand aufgebaut sowie ein Referenzdrehmomentsensor eingesetzt. Die Ergebnisse dieser Validierung werden in diesem Fachaufsatz vorgestellt.   The measurement of torque via sensors as well as the generation of torque are the basis of many industrial sectors. Within a research project an optical and non-contact measurement method to detect the absolute rotation angle and torque was developed. For comparison with the current state of the art torque sensors a test stand was built and compared to a reference torque sensor. The results of this validation are presented in the present paper.

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Crossover from positive to negative optical torque in mesoscale optical matter

Nature Communications ◽

10.1038/s41467-018-07376-7 ◽

2018 ◽

Vol 9 (1) ◽

Cited By ~ 21

Author(s):

Fei Han ◽

John A. Parker ◽

Yuval Yifat ◽

Curtis Peterson ◽

Stephen K. Gray ◽

...

Keyword(s):

Optical Torque

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Numerical Modeling of Photonic Jet behind Triangular Prism

Asian Journal of Research and Reviews in Physics ◽

10.9734/ajr2p/2021/v4i130131 ◽

2021 ◽

pp. 1-6

Author(s):

Arnold Abramov ◽

Yutao Yue ◽

Mingming Wang ◽

Zongyang Wang ◽

Yajun Xu

Keyword(s):

Plane Waves ◽

Isosceles Triangle ◽

Triangular Prism ◽

Jet Formation ◽

Photonic Jet ◽

Shadow Side ◽

Difference Time ◽

Electromagnetic Plane Waves ◽

High Field Intensity ◽

Sub Wavelength

The scattering of electromagnetic plane waves by triangular prism and its truncated form (the isosceles triangle and the trapezoid are transverse sections, respectively) has been studied in order to determine possibility of high field intensity (photonic jet) formation. Using high-resolution finite-difference time-domain simulation, an optimal relationship between the wavelength and the size of the prism was found to form photonic jet with sub wavelength waist on the shadow side of the prism. Truncation of the prism (with trapezoids as transverse sections) leads to an improvement in the characteristics of photonic jets (intensity, length and waist). A qualitative explanation of the simulation results obtained is presented.

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