Photoinduced Magnetic Force Microscopy: Enabling Direct and Exclusive Detection of Optical Magnetism

Abstract

Modern optical nano-elements pursue ever-smaller sizes and individualized functionalities. Those elements that can efficiently manipulate the magnetic field of light boast promising future applications with a great challenge: the magnetic near field is irretrievable from conventional optical far-field characterization. Here we propose photoinduced magnetic force microscopy to directly and exclusively sense the magnetic field of light at the nanoscale. The proposed instrument exploits a magnetic nanoprobe with exclusive magnetic excitation under structured light illumination. The magnetic nanoprobe detects the photoinduced magnetic force, which is defined as the dipolar Lorentz force exerted on the photoinduced magnetic dipole in the nanoprobe. Since the resulting magnetic force is proportional to the incident magnetic field, the measured force reveals the magnetic near-field distribution at the nanoscale. The proposed instrument represents a fundamental step towards comprehensive electric and magnetic near-field detection and/or manipulation in single nano-element optical devices.

References in corpus (9)

• Negative Index of Refraction in Optical Metamaterials
• Backward Pulling Force from a Forward Propagating Beam
• An electromagnetic multipole expansion beyond the long-wavelength approximation
• Magnetic Dipole and Electric Quadrupole Transitions in the Trivalent Lanthanide Series: Calculated Emission Rates and Oscillator Strengths
• On the experimental investigation of the electric and magnetic response of a single nano-structure
• Generation of Vortex Beams with Strong Longitudinally Polarized Magnetic Field by Using a Metasurface
• Near-Field Nanoprobing Using Si Tip-Au Nanoparticle Photoinduced Force Microscopy with 120:1 Signal-to-Noise Ratio, Sub-6-nm Resolution
• Focused Azimuthally Polarized Vector Beam and Spatial Magnetic Resolution below the Diffraction Limit
• Photo-induced Magnetic Force Between Nanostructures