Optimizing detection methods for terahertz bioimaging applications

We propose a new approach for efficient detection of terahertz (THz) radiation in biomedical imaging applications. A double-layered absorber consisting of a 32-nm-thick aluminum (Al) metallic layer, located on a glass medium ( SiO 2 ) of 1 mm thickness, was fabricated and used to design a fine-tuned absorber through a theoretical and finite element modeling process. The results indicate that the proposed low-cost, double-layered absorber can be tuned based on the metal layer sheet resistance and the thickness of various glass media. This can be done in a way that takes advantage of the diversity of the absorption of the metal films in the desired THz domain (6 to 10 THz). It was found that the composite absorber could absorb up to 86% (a percentage exceeding the 50%, previously shown to be the highest achievable when using single thin metal layer) and reflect of the incident THz power. This approach will enable monitoring of the transmission coefficient (THz transmission fingerprint) of the biosample with high accuracy, while also making the proposed double-layered absorber a good candidate for a microbolometer pixel’s active element.