Investigation of optimal THz band for corneal water content quantification

Terahertz imaging and sensing is currently being explored as a method for corneal disease detection as systems operating in this spectrum are sensitive to corneal-water content and thickness. The free-space wavelength of the low-frequency THz band is close to the typical human corneal central thickness (CCT, 540m) and the water content is distributed in an approximately linear gradient increasing from anterior (front) to posterior (back). The cornea presents as a lossy thin film at THz frequencies, thus the resolution of longitudinal modes via broadband reflectometry should allow for the extraction of thickness, corneal anterior water content (CAWC) and corneal posterior water content (CPWC) [1]. The implementation of this sensing technology requires identification of an optimal THz frequency band.