Analytica 2024: Fraunhofer IOF presenting tiny spectrometer

03 Apr 2024

Featuring 39 fibers mapped onto single camera, sensor has applications in quality assurance, analytics.

Fiber-coupled microspectrometer array maps 39 spectra onto CMOS sensor.

Researchers at the Fraunhofer Institute for Applied Optics and Precision Engineering (IOF) have developed a compact spectrometer module. It maps spectra from 39 optical fibers onto a single camera sensor in a small space, enabled by a special micro-optical system.

The technology, which has potential for applications in quality assurance and analytics, will be presented at the analytica trade fair in Munich, next week (April 9th to 12th).

If an application needs to spectrally analyze the light from many distant measuring points, one can either use several separate micro spectrometers or complex laboratory equipment. Neither approach is suitable in flexible or even mobile applications. The novel IOF module is a solution because it maps the spectral information onto the image sensor of a tiny camera.

The researchers from Jena have developed a special micro-optical system for processing the light transmitted via optical fibers. It consists of many spectrometers arranged next to each other, forming a spectrometer array. Each channel contains a prism-grating-prism arrangement between achromatic micro lenses. The micro lenses are separated by spacers to prevent crosstalk between the channels.

This array arrangement allows to mount all spectrometer channels at once and results in an optical system length of less than 20 mm. Despite the limited dimensions, the system maps the spectrum from around 400 to 800 nm. A resolution of 0.6 nm per pixel is achieved with the corresponding CMOS sensor.

Rugged microspectrometer can easily be integrated into demanding environments.

Compact optics

The technology has been developed for applications where spectral measurements are required at many positions or over large areas. This applies, for example, to the optical analysis of coatings or printings, to parallel measurements in bioanalytics as well as to digital agriculture, such as to check the health status of plants. Thanks to the integrated design, the setup is robust and can be integrated into existing systems easily.

The IOF team has developed the technology to application readiness over the past three years with the support of the Thüringer Aufbaubank. The task now is to optimize it for specific applications with the appropriate partners. For example, the spectral resolution could be adjusted, or the spectral measuring range can be extended to 1,600 nm – even different parameters of the channels are conceivable, states the IOF.

• The Fraunhofer IOF team is presenting the compact micro spectrometer at analytica in Munich from April 9 to 12 at the Fraunhofer booth A3.407.