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Transverse orbital angular momentum of amplitude perturbed fields
Scott W Hancock1, Nishchal Tripathi1, Manh S Le1
1Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, USA.
Nanophotonics (Berlin, Germany)
|April 4, 2025
Summary
This study measures the change in transverse orbital angular momentum (tOAM) per photon induced by amplitude perturbations in optical pulses. Even pulses with initially zero tOAM can gain net tOAM due to these perturbations.
Area of Science:
- Optics and Photonics
- Quantum Mechanics
- Electromagnetism
Background:
- Transverse orbital angular momentum (tOAM) is a key property of light.
- Understanding how external perturbations affect tOAM is crucial for optical applications.
- Previous theoretical frameworks for tOAM require clarification.
Purpose of the Study:
- To experimentally measure the change in tOAM per photon induced by amplitude perturbations.
- To validate a theoretical model of spatiotemporal torque and tOAM.
- To investigate the role of tOAM density distribution in induced tOAM.
Main Methods:
- Experimental measurement of Δ⟨L⟩ per photon in optical pulses.
- Comparison of experimental results with theoretical calculations and simulations.
- Analysis of spatiotemporal tOAM density distributions.
Main Results:
- Experimental results show excellent agreement with theoretical predictions.
- Demonstrated that amplitude perturbations can induce net tOAM even in pulses with zero initial tOAM.
- Identified the spatiotemporal distribution of tOAM density as critical for determining induced tOAM.
Conclusions:
- The study confirms the validity of the tOAM theory for spatiotemporal torque.
- Amplitude perturbations are shown to be a viable mechanism for inducing tOAM.
- Clarified fundamental principles for analyzing tOAM experiments and simulations.
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