Cellulose is one of the most abundant biopolymers on earth. It is a sustainable and renewable raw material with many beneficial properties. Due to its sustainable availability and its ability to manage light interactions, cellulose is increasingly used in optoelectronic devices to replace fossil-based polymers.^[1] In order to build a completely cellulose-based optical fiber, figure 1, it is therefore necessary to determine the optical properties such as transmission and refractive index as a function of wavelength. For this purpose, corresponding films of cellulose and cellulose derivatives cellulose diacetate, cellulose acetate propionate and cellulose acetate butyrate are prepared and optically characterized. For the fiber production, cellulose can be dissolved and then processed into a regenerated fiber via a simple wet-spinning process. The fibers can then be coated with cellulose derivatives to form a core-cladding optical fiber structure. The generated cellulose-based optical fibers exhibit minimum attenuations between 56 and 82 dB m⁻¹ at around 860 nm.^[2] The ultimate transmission loss limit of the cellulose-based optical fibers was simulated to characterize the attenuation progression. Cellulose-based biopolymer optical fibers could attain theoretical attenuation minima of 84.6 × 10⁻³ dB m⁻¹ (507 nm), 320 × 10⁻³ dB m⁻¹ (674 nm), and 745.2 × 10⁻³ dB m⁻¹ (837 nm). The presented cellulose-based optical fibres might substitute fossil-based polymer optical fibers in the future.

References
[1] M. Reimer; C. Zollfrank Advanced Energy Materials (review), 2021, 11, 2003866
[2] M. Reimer, D. Van Opdenbosch, C. Zollfrank Biomacromolecules, 2021, 22(8), 3297