Identification of nano-scale films for THz sensing
MetadataShow full item record
There is a continued interest in the terahertz (THz) spectral range due to potential applications in spectroscopy and imaging. Real-time imaging in this spectral range has been demonstrated using microbolometer technology with external illumination provided by quantum cascade laser based THz sources. To achieve high sensitivity, it is necessary to develop microbolometer pixels using enhanced THz absorbing materials. Metal films with thicknesses less than the skin depth for THz frequencies can efficiently absorb THz radiation. However, both theoretical analysis and numerical simulation show that the maximum THz absorption of the metal films is limited to 50%. Recent experiments carried out using a series of Cr and Ni films with different thicknesses showed that absorption up to the maximum value of 50% can be obtained in a broad range of THz frequencies. A further increase in absorption requires the use of resonant structures. These metamaterial structures consist of an Al ground plane, a SiO2 dielectric layer, and a patterned Al layer. Nearly 100% absorption at a specific THz frequency is observed, which strongly depends on the structural parameters. In this paper, the progress in the use of thin metal films and metamaterial structures as THz absorbers will be described.
The article of record as published may be found at http://dx.doi.org/10.1117/12.918624
Showing items related by title, author, creator and subject.
Apostolos, Karamitros (Monterey, California. Naval Postgraduate School, 2011-09);The terahertz (THz) region of the electromagnetic spectrum covers frequencies ranging from approximately 100 GHz to 10 THz. This region of the spectrum has not been fully utilized due to the lack of compact and efficient ...
Carlisle, James Allen (1972-12);Light from a neodymium doped glass laser was focused in hydrogen gas at pressures from 20 millitorr to 62 atmospheres in order to produce optical breakdown of the gas. In the cases where breakdown was experienced, absorption ...
Design and characterization of terahertz-absorbing nano-laminates of dielectric and metal thin films Bolakis, Christos; Grbovic, Dragoslav; Lavrik, Nickolay V; Karunasiri, Gamani (2010-01-01);A terahertz-absorbing thin-film stack, containing a dielectric Bragg reflector and a thin chromium metal film, was fabricated on a silicon substrate for applications in bi-material terahertz (THz) sensors. The Bragg reflector ...