A room-temperature, high-sensitivity Golay-type terahertz array detector in optical readout

We present a micro-structured Golay-cell THz array detector with the sensitive mechanism from the THz optical radiation to thermal absorption, to pressure deformation, and then to optical phase, realizing highly sensitive, room temperature operation. The device features novel micro gas-cavity architecture with a carbon nanotube absorption layer and a flexible reflective membrane, which transduces absorbed THz radiation into a measurable optical phase signal (caught by a Hartmann wavefront sensor) via membrane deformation. Multiphysics simulations were carried out to optimize key parameters of the cavity size, membrane thickness, and cavity height, and an optimal geometry was revealed with maximum displacement responsivity and moderate response speed. Based on simulations, a prototype array detector was fabricated and verified its THz response. The uncooled detector exhibits high displacement responsivity of around 6.93 mm/W at a frequency of 0.1 THz and realizes a clear spatially resolved response. The observed membrane deformation agrees with simulation predictions and scales linearly with incident THz power. Pixel response uniformity is up to an average value of around 83%, literally demonstrating its viability for THz imaging. Our work breaks the strict cooling requirements and the dilemma of only being able to achieve single point detection and offers a promising path toward array THz imaging.