Figure 1.

The design and response spectra of antenna-coupled Ti-$\mu$bolometers. Top panel (a): The design and schematic cross-section of the Ti-$\mu$bolometer coupled with different antennas for 0.3 THz, 0.7 THz and for wideband detection (from left to right). Digital photos show top views of Ti-$\mu$bolometer detectors coupled with dipole antenna design. The geometry of the titanium bridge amounts to 12 $\mathsf{\mu }$m length and 2 $\mathsf{\mu }$m width. The angles $\theta$ and $\varphi$ in photo of the wideband detector are defined as sample rotation angle for polarization measurements and the polar angle of antenna fingers, respectively. The design is adapted from Refs. [22,23]. Panel (b): Simulated spectra of the normalized antenna gain for the different antenna’s designs. Panel (c): Response spectra of the devices were measured using Fourier transform far-infrared spectrometer as described in Ref. [22].