Journal of The Optical Society of America B-optical Physics | 2019
Characterization of thin-film optical properties by THz near-field imaging method
Abstract
We present a new method to characterize thin-film electro-optic materials. The method is based on resolving the electric and/or magnetic field distributions in the near-field region of a split-ring resonator (SRR) designed for the terahertz (THz) frequency range. We experimentally validate our simulations by THz near-field imaging of SRRs directly patterned in contact with a thin-film lithium niobate crystal as a sensor. Furthermore, we analytically study the effect of the different applied electric field polarizations and calculate the sensitivity of the sensor via various polarizations of probe beams.