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Updated: May 13, 2026
08:01
Spectral and Angle-Resolved Magneto-Optical Characterization of Photonic Nanostructures
Published on: November 21, 2019
Negative experimental evidence for magneto-orbital dichroism
Renaud Mathevet1, Bruno Viaris de Lesegno, Laurence Pruvost
1CNRS-INSA-UJF-UPS, Laboratoire National des Champs Magnetiques Intenses, F31400 Toulouse, France. renaud.mathevet@lncmi.cnrs.fr
Optics Express
|March 14, 2013
Summary
Researchers searched for magnetic orbital dichroism (MOD), a light-matter interaction involving orbital angular momentum (OAM). They found MOD is significantly smaller than magnetic circular dichroism (MCD), suggesting higher-order interactions are involved.
Area of Science:
- Optics and Photonics
- Quantum Optics
- Condensed Matter Physics
Background:
- Light beams possess both spin angular momentum (SAM) and orbital angular momentum (OAM).
- Circular dichroism (CD) detects SAM via differential absorption of circularly polarized light.
- Magnetic circular dichroism (MCD) is observed in isotropic materials under magnetic fields.
- Previous studies suggest OAM-dependent dichroism is absent in chiral matter.
Purpose of the Study:
- To experimentally search for magnetic orbital dichroism (MOD), the OAM analogue of MCD.
- To quantify the magnitude of MOD in a specific Nd:YAG transition.
- To explore the theoretical underpinnings of potential MOD effects.
Main Methods:
- Experimental setup designed to detect differential light absorption based on OAM sign.
- Utilized a Nd:YAG 4/9/2 →4 F5/2 transition, primarily of electric dipole nature.
- Comparison of observed effects with established MCD measurements.
Main Results:
- MOD was experimentally investigated under well-defined conditions.
- The observed MOD effect, if present, was found to be less than 10⁻⁴ times the MCD.
- The Nd:YAG transition studied is predominantly electric dipole in nature.
Conclusions:
- Magnetic orbital dichroism (MOD) is experimentally found to be extremely small.
- The primary light-matter interaction for MOD is likely higher-order, such as electric quadrupole.
- This finding contrasts with the more readily observed MCD effect.
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