Spectral Reconstruction Using Broadband Inkjet-Printed Optical Filters

Year: 2026

Authors: Baini L., Jin Q.H., Zhang Q.S., Gomard G., Lemmer U., Bartolini P., Taschin A., Wiersma D.S., Torre R., Boschetti A.

Autors Affiliation: Univ Florence, European Lab Non Linear Spect, Sesto Fiorentino, Italy; Karlsruhe Inst Technol, Light Technol Inst, Karlsruhe, Germany; Carl Zeiss, Zeiss Innovat Hub, Eggenstein Leopoldshafen, Germany; CNR INO, Consiglio Nazl Ric, Ist Nazl Ott, Sesto Fiorentino, Italy; Univ Firenze, Dipartimento Fis Astron, Sesto Fiorentino, Italy; Ist Nazl Ric Metrol INRiM, Turin, Italy.

Abstract: Reconstructive spectroscopy offers a promising route toward miniaturization by replacing dispersive optics with computational recovery from encoded measurements, but existing implementations typically rely on complex nanofabrication and highly decorrelated encoding elements, limiting manufacturability and robustness. Here, we demonstrate a reconstructive spectrometer based on inkjet-printed interferometric optical filters featuring a minimalist tri-layer architecture and high optical throughput. Contrary to prevailing design principles, we show that smooth, strongly correlated filter responses can nonetheless enable accurate spectral reconstruction over a 400 nm visible bandwidth. By adaptively selecting optimized subsets of filters using a custom genetic algorithm, the system exploits the high signal-to-noise ratio of correlated encoders while maintaining reconstruction fidelity. In addition, we introduce a calibration and reconstruction framework that requires only minimal a priori knowledge of the measured spectra, increasing the viability of practical deployment of reconstructive spectrometers. The resulting procedure combines scalable fabrication, adaptive encoding, and robust reconstruction, with a strong basis of versatile and manufacturing-ready encoding elements.

Journal/Review: ADVANCED OPTICAL MATERIALS

More Information: The work has been financially supported by the project CNR-FOE-LENS, by the European Union’s NextGeneration EU Programme with the I-PHOQS Infrastructure [IR0000016, ID D2B8D520, CUP B53C22001750006]. L.B. gratefully acknowledges the financial support of the Italian Ministry of University and Research for the PhD program DM 630/2024, co-funded under the PNRR.
KeyWords: convex optimization; Inkjet-printed filters; optical filters; optics; reconstructive spectroscopy; spectroscopy
DOI: 10.1002/adom.71918