|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.