Enabling Lignocellulose-Sourced\nFeedstocks to Fabricate\nOptical Filters with Desired Blocking Wavelength

Near-infrared (NIR) filters have broad applications in\nfields such\nas information safety and privacy protection and environmental monitoring.\nTraditional NIR filters primarily rely on complex optical designs\nand environmentally unfriendly substrates, while lignocellulose-sourced\nNIR filters do not achieve the desired blocking wavelength and therefore\nface challenges in various application conditions. In this study,\nwe propose a thickness adjustment strategy to precisely control the\nblocking wavelength of the NIR optical filters. The obtained optical\nfilters with tailored thickness exhibited selective blocking wavelength\nin visible region (400–650 nm) as well as a high NIR transmittance\n(over 90%) and ultralow haze at 1400 nm. Given their selective wavelength\nblocking and high NIR transmittance, these bioselectors demonstrate\npotential applications in NIR optical fields, such as data security\nand privacy protection, presenting a promising advancement in next-generation\nsustainable NIR optical materials fabricated from all-lignocellulose\nfeedstocks.