3D-printed miniature spectrometer for the visible range with a 100 × 100 μm2 footprint - Research article summary

Sep 16, 2026

Miniaturised spectroscopic devices enable new information channels for size-critical applications such as endoscopy and consumer electronics. Existing micrometre-scale computational spectrometers remain calibration-sensitive and rely on complex reconstruction algorithms. This article presents an angle-insensitive 3D-printed miniature spectrometer delivering a direct separated spatial–spectral response, fabricated via two-photon direct laser writing and a super-fine inkjet process. It operates in the visible range 490–690 nm with reported resolution at 532 and 633 nm and can be printed onto camera sensors to form a macro-pixel for snapshot hyperspectral imaging.

LanguageEnglish

CategoryGeneral

FormatPDF

Pages11

Reading Time4 min

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Abstract

Introduction

Micro-optics enabled by femtosecond direct laser writing

Motivation for integrated micro spectrometer

Size-critical applications

Categories of miniaturised spectrometers

Positioning of the presented device

Toulouse et al. Light: Advanced Manufacturing (2021)2:2 Official journal of the JHL 2689-9620 [https://doi.org/10.37188/lam.2021.002](https://doi.org/10.37188/lam.2021.002) [www.light-am.com](www.light-am.com) Article Open Access 3D-printed miniature spectrometer for the visible range with a 100 × 100 μm2 footprint Andrea Toulouse1,2,*, Johannes Drozella1,2, Simon Thiele1,2, Harald Giessen2,3 and Alois Herkommer1,2 Abstract The miniaturisation of spectroscopic measurement devices opens novel information channels for size critical applications such as endoscopy or consumer electronics. Computational spectrometers in the micrometre size range have been demonstrated, however, these are calibration sensitive and based on complex reconstruction algorithms. Herein we present an angle-insensitive 3D-printed miniature spectrometer with a direct separated spatial-spectral response. The spectrometer was fabricated via two-photon direct laser writing combined with a super-fine inkjet process. It has a volume of less than 100 × 100 × 300 μm3. Its tailored and chirped high-frequency grating enables strongly dispersive behaviour. The miniature spectrometer features a wavelength range of 200 nmin the visible range from 490 nm to 690 nm. It has a spectral resolution of 9.2 ± 1.1 nm at 532 nm and 17.8 ± 1.7 nm at a wavelength of 633 nm. Printing this spectrometer directly onto camera sensors is feasible and can be replicated for use as a macro-pixel of a snapshot hyperspectral camera. Introduction The field of micro-optics has been transformed by the use of femtosecond direct laser writing as a 3D printing technology since the early 2000s. Both the complexity and surface quality have advanced from simple microlenses1,2 and achromats3 to multi-lens and multi-aperture objectives4,5 . A similar development has occurred with diffractive optics, which have evolved from simple gratings6 to stacked diffractive microlens systems7 . Along with imaging optics, photonic crystals8, waveguides9, 10, and collimators11, complex beam shapers12–14 have been demonstrated. This rapid development reflects the significant potential of 3D printing technology in micro-optics. Advancements have enabled access to the millimetre scale and larger with 3D printing technology15–17. Meanwhile, the almost unlimited Correspondence: Andrea Toulouse ([toulouse@ito.uni-stuttgart.de](toulouse@ito.uni-stuttgart.de)) 1Institute of Applied Optics (ITO), University of Stuttgart, Pfaffenwaldring 9, 70569 Stuttgart, Germany 2Research Center SCoPE, University of Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany Full list of author information is available at the end of the article. optical design freedom that it offers makes further miniaturisation possible, thereby increasing the given functionality in decreasing volumes on the micrometre scale. The aim of this study was to enhance both the complexity and miniaturisation of 3D-printed micro-optics and to create an entire integrated measurement system, a spectrometer, in a 100 × 100 × 300 μm3 volume. The miniaturisation of spectroscopic measurement devices opens novel information channels for size-critical applications. For instance, medical engineering, consumer electronics, and downscaled chemical engineering could benefit from a cost-effective, efficient, and readily integrated spectroscopic micro-device. Spectra could be retrieved from the tip of a distal-chip endoscope with abending radius smaller than that of an optical fibre to explore regions that are otherwise inaccessible. With the size of one or two orders of magnitude smaller than a smartphone camera objective, integration into consumer electronics is realisable for applications such as skin disease diagnosis18 and counterfeit bank note detection19. © The Author(s) 2021 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduct

FAQs

What problem does the article address with existing miniature spectrometers?

Existing micrometre-scale approaches can be calibration-sensitive and depend on complex reconstruction algorithms, limiting robust use in compact systems.

How is the miniature spectrometer fabricated?

It is produced using two-photon direct laser writing combined with a super-fine inkjet process.

What measurement principle and performance does the spectrometer provide?

It delivers an angle-insensitive, direct separated spatial–spectral response and covers the visible range from 490 to 690 nm, with wavelength-dependent spectral resolution reported at 532 nm and 633 nm.

Sep 16, 2026

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