Fig. 1: Schematics of the hybrid Tamm-cavity detector operating in the terahertz band and its resonance characteristics.

a Schematic diagram of the hybrid Tamm-cavity detector. Silicon is shown in gray, air in white, and the mirror back on the substrate in yellow. b Reflectance spectra of a bare three-layer DBR and a hybrid Tamm cavity at d_substrate = 510 μm. The different extremum points correspond to the cavity’s resonant modes in Eq. (2). c Spatial distribution of the refractive index of the multilayer dielectrics in the hybrid Tamm cavity in the vertical direction. The yellow region represents the position of the metal mirror at the back of the detector chip with d_substrate = 510 μm. d–f Spatial distributions of the enhancement factor of the electric field intensity (|E|²/|E_i|²) along the vertical purple dashed line in (a) at 0.4004 THz [A in (b)], 0.4300 THz [B in (b)], and 0.4790 THz [C in (b)]. The black dashed lines indicate the electric field intensity |E_d|² at the detector (Y = d_substrate = 510 μm). g Electric field enhancement factor (|E_d|²/|E_i|²) at the detector with zero, one, or three Si/air layers with d_substrate = 510 μm. h Relation between the electric field (|E_d|) and substrate thickness of the detector chip (d_substrate) for a hybrid Tamm cavity with three Si/air layers in the range 0.25–0.6 THz. The five white dashed lines were calculated by Eq. (2) and indicate the resonant modes of the cavity with N = 2, 3, 4, 5, or 6, respectively. The horizontal white line indicates the resonance characteristics of the hybrid Tamm cavity at d_substrate = 510 μm. The dots labeled A, B, and C correspond to the cases illustrated in (b, d, e), and (f). The band gap of DBR is also marked with vertical white dashed lines on the graph. i Spectral characteristics of the electric field intensity |E_d|² in a hybrid Tamm cavity with different thicknesses of the substrates of the detector chips.