Spatial Symmetry and Conservation of Orbital Angular Momentum in Spontaneous Parametric Down-Conversion

Journal Article · Fri Oct 17 00:00:00 EDT 2008 · Physical Review Letters

DOI:https://doi.org/10.1103/PHYSREVLETT.101.163602· OSTI ID:21179819

Sheng, Feng; Kumar, Prem ^[1]

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1. Center for Photonic Communication and Computing, EECS Department, Northwestern University, Evanston, Illinois 60208-3118 (United States)

Directly contradictory arguments coexist regarding the conservation rule of orbital angular momentum in spontaneous parametric down-conversion. We analytically show how this rule is decided by spatial symmetry. We discover that the down-converted photon pairs can carry non-negligible extrinsic orbital angular momentum in the degrees of relative-movement freedom due to spatial symmetry breaking, leading to nonconservation of total orbital angular momentum in type-II down-conversion. Also, we demonstrate that the traditional technique does not measure the extrinsic orbital angular momentum.

• OSTI ID: 21179819
• Journal Information: Physical Review Letters, Vol. 101, Issue 16; Other Information: DOI: 10.1103/PhysRevLett.101.163602; (c) 2008 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
INVARIANCE PRINCIPLES
ORBITAL ANGULAR MOMENTUM
PHOTONS
SYMMETRY
SYMMETRY BREAKING