9 September 2014 Investigation of microelectromechanical systems bimaterial sensors with metamaterial absorbers for terahertz imaging
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Optical Engineering, 53(9), 097103 (2014). doi:10.1117/1.OE.53.9.097103
Abstract
One attractive option to achieve real-time terahertz (THz) imaging is a microelectromechanical systems (MEMS) bimaterial sensor with embedded metamaterial absorbers. We have demonstrated that metamaterial films can be designed using standard MEMS materials such as silicon oxide (SiOx), silicon oxinitrate (SiOxNy), and aluminum (Al) to achieve nearly 100% resonant absorption matched to the illumination source, providing structural support, desired thermomechanical properties and access to external optical readout. The metamaterial structure absorbs the incident THz radiation and transfers the heat to bimaterial microcantilevers that are connected to the substrate, which acts as a heat sink via thermal insulating legs, allowing the overall structure to deform proportionally to the absorbed power. The amount of deformation can be probed by measuring the displacement of a laser beam reflected from the sensor’s metallic ground plane. Several sensor configurations have been designed, fabricated, and characterized to optimize responsivity and speed of operation and to minimize structural residual stress. Measured responsivity values as high as 1.2  deg/μW and time constants as low as 20 ms with detectable power on the order of 10 nW were obtained, indicating that the THz MEMS sensors have a great potential for real-time imaging.
© 2014 Society of Photo-Optical Instrumentation Engineers (SPIE)
Fabio Alves, Dragoslav Grbovic, Gamani Karunasiri, "Investigation of microelectromechanical systems bimaterial sensors with metamaterial absorbers for terahertz imaging," Optical Engineering 53(9), 097103 (9 September 2014). http://dx.doi.org/10.1117/1.OE.53.9.097103
JOURNAL ARTICLE
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KEYWORDS
Sensors

Terahertz radiation

Metamaterials

Microelectromechanical systems

Aluminum

Absorption

Quantum cascade lasers

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