The measurement of local field enhancement typically involves techniques like near-field scanning optical microscopy (NSOM), which can resolve the enhanced fields at the nanoscale. Spectroscopic methods, including Raman spectroscopy and fluorescence spectroscopy, are also used to indirectly assess field enhancement by measuring the increased signal intensity. Computational methods such as finite-difference time-domain (FDTD) simulations can predict and visualize local field distributions.
