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Updated: Jun 19, 2026
07:56
A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
Published on: September 5, 2019
Nonlinear conversion of photon spin to photon orbital angular momentum
1Naval Research Laboratory, Plasma Physics Division, Washington, DC 20375, USA. daniel.gordon@nrl.navy.mil
Optics Letters
|November 3, 2009
Summary
A powerful laser pulse with spin angular momentum generates second-harmonic radiation containing both spin and orbital angular momentum. This occurs due to plasma interactions and laser-induced phase variations.
Area of Science:
- Plasma Physics
- Nonlinear Optics
- Laser-Plasma Interactions
Background:
- Intense laser pulses carry significant angular momentum.
- Second-harmonic generation (SHG) is a key nonlinear optical process.
- Understanding light-matter interactions in plasma is crucial.
Purpose of the Study:
- To investigate the nature of second-harmonic radiation produced by a laser pulse with pure spin angular momentum in plasma.
- To identify the origins of spin and orbital angular momentum in the generated radiation.
Main Methods:
- Focusing a relativistically intense, ultrashort laser pulse with purely spin angular momentum into a plasma.
- Analyzing the properties of the resulting second-harmonic radiation.
Main Results:
- The second-harmonic radiation exhibited equal contributions of spin and orbital angular momentum.
- An azimuthal phase variation in the nonlinear current density was identified as the source of orbital angular momentum.
- This phase variation was linked to radial nonuniformity driven by ponderomotive blowout.
Conclusions:
- Relativistically intense laser pulses with spin angular momentum can generate second-harmonic radiation with both spin and orbital components in plasma.
- Ponderomotive blowout plays a critical role in establishing the conditions for orbital angular momentum generation.
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