2024/01/29 by Zhang, Chang, Yalavarthi, Eeswar K., Giroux, Mathieu +6 · 5 citations
#Applied Physics (physics.app-ph) #FOS: Physical sciences #Optics (physics.optics)
paper · doi:10.48550/arxiv.2401.16503
We achieve high detectivity terahertz sensing using a silicon nitride nanomechanical resonator functionalized with a metasurface absorber. High performances are achieved by striking a fine balance between the frequency stability of the resonator, and its responsivity to absorbed radiation. Using this approach, we demonstrate a detectivity D^*=3.4×109~cm⋅√(Hz)/W and a noise equivalent power NEP=36~pW/√(Hz) that outperform the best room-temperature on-chip THz detectors (i.e., pyroelectrics). Our optical absorber consists of a 1-mm diameter metasurface, which currently enables a 0.5-3 THz detection range but can easily be scaled to other frequencies in the THz and infrared ranges. In addition to demonstrating high-performance terahertz sensing, our work unveils an important fundamental trade-off between high frequency stability and high responsivity in thermal-based nanomechanical radiation sensors.