2D　materials　hold　potential　for　developing　low-cost,　high-performance　broadband　polarized　infrared　photodetectors.　However,　the　development　of　2D　broadband　polarized　infrared　photodetectors　is　largely　constrained　by　the　fixed　bandgap　spectral　(cutoff　wavelength)　limitations　of　available　semiconductors.　Here,　an　approach　is　presented　that　leverages　anisotropic　interlayer　excitons　(IEXs)　within　a　type-II　van　der　Waals　heterojunction,　achieving　polarization　photoresponse　beyond　the　intrinsic　bandgap　spectral　limits　of　its　constituent　semiconductors.　By　constructing　heterojunctions　using　CrPS4　and　ReS2,　a　unique　type-II　band　alignment,　enabling　strong　anisotropic　optical　excitation　is　achieved　through　the　interlayer　sub-bandgap,　which　is　lower　than　the　intrinsic　bandgaps　of　both　CrPS4　and　ReS2.　The　heterojunction　exhibits　a　responsivity　of　0.3 A W−1　and　a　polarization　ratio　of　1.3　at　an　incident　photon　energy　of　0.8 eV,　comparable　to　naturally　anisotropic　materials　with　intrinsic　bandgaps.　Additionally,　the　potential　of　anisotropic　IEXs　is　demonstrated　for　dual-band　polarization　detection　by　introducing　a　ReS2/CrPS4/MoS2　heterojunctions　with　distinct　inte　rlayer　sub-bandgaps.　This　flexible　design　of　IEXs　offers　a　new　platform　for　multi-dimensional　optical　sensing　and　on-chip　optoelectronic　applications.　©　2024　Wiley-VCH　GmbH.