Far-infrared wavelength range (30μ- 1000μm) is an important spectral region for several applications such as thermal imaging, chemical sensing, astronomical imaging, among others. Therefore, miniaturization of far infrared (FIR) optical devices is of great technological interest. Recently, anisotropic 2D van der Waals crystals have garnered substantial attention for potential applications in the area of visible to mid-infrared (MIR) photonics. However, these materials have been relatively less explored for their applications in FIR spectral region for photonic devices. Molybdenum Trioxide (α-MoO3) - a member of the van der Waals semiconductor family exhibits strong in-plane anisotropy, using which one can engineer the polarization state of the incident light - a property highly relevant for photonic device applications. As example device applications, in this work we investigate the potential of α-MoO3 for two optical components in the FIR spectral region (265 cm-1-360 cm-1), i.e. polarizer and waveplates. We evaluate the performance metrics of our proposed FIR polarizer system using a theoretical model and predict a large extinction ratio (> 30 dB). Secondly we optimize the thickness of α-MoO3 for waveplate application. Our theoretical analysis will pave the way for the development of efficient thin-film based photonic devices for FIR spectral region.
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