Thermal imager using metamaterials

US8450690B2 · kind B2 · utility

Assignees

• TRUSTEES OF BOSTON UNIVERSITY · US
• The Trustees of Boston College · US

Inventors

• Richard D. Averitt · Newton, US
• Xin Zhang · Medford, US
• Hu Tao · Medford, US
• Andrew Strikwerda · Brookline, US
• Willie Padilla · Newton, US
• Eric A. Shaner · Rio Rancho, US

Key dates

• Filing date: Oct 4, 2011
• Grant date: May 28, 2013
• Expiry date: Oct 4, 2031

Classification

• Technology area (CPC G): Physics
• CPC primary: G01J5/40
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An apparatus and method are disclosed for detecting terahertz radiation at room temperature. A detecting pixel includes a sub-wavelength split-ring resonator, and is mechanically coupled to (but thermally decoupled from) a substrate via a cantilever formed from two materials that have a significant mismatch in their thermal expansion coefficients. Incident radiation causes the split-ring resonator to resonate, thereby generating heat that is transferred to the cantilever, causing the cantilever to flex. An optical readout system includes a secondary light source, such as a laser, that shines on a reflective surface on the pixel, whereby a photodiode detects the reflected light and permits calculation of a relative deflection of the pixel in the nanometer range. An exemplary detector has a noise equivalent power rating of approximately 60 pW/√Hz.