Micro- and Nanooptics

Our Extensive Competencies and Expertise

The Fraunhofer IOF plays a key role in the ESA CO2M mission, which is part of the Copernicus program. Its satellites are flying spectrometers that enable the global measurement of CO2 emissions. We develop and manufacture the optical heart of the instruments: the spectrometric dispersers, which have been specially developed for use in space. These consist of two prisms and a grating, which are connected using a direct bonding process. The nanostructured gratings are characterized by an exceptionally high efficiency of over 90 % and a low degree of polarization. This is achieved through a unique grating design in which the grating trenches are filled with a highly refractive material. This precision technology minimizes stray light and optimizes the spectrometer's signal-to-noise ratio. With this groundbreaking development, IOF is making a decisive contribution to better understanding climate change and enabling more effective measures.

As part of the ESA mission FORUM (Far-infrared Outgoing Radiation Understanding and Monitoring), the Fraunhofer IOF has developed a key technology to analyze the Earth's thermal radiation balance in the far-infrared range (8 to 100 µm). At the center is a microstructured diamond beam splitter, which is ideal for this application due to its exceptional properties such as high transmission over a broad wavelength spectrum. The microstructures on the surface of the diamond enable broadband antireflection coating, which is essential for the precise functioning of the spectrometer on board the satellite. These structures were created using state-of-the-art technologies and are in the nanometre range in order to minimize reflections and maximize the efficiency of the measurements. The development of this technology, which has been supported by ESA since 2019, represents a significant advance in the processing of diamond and makes a decisive contribution to improving climate research

The Fraunhofer IOF is involved in numerous missions of the Sentinel program, which is part of the European Copernicus program for earth observation. The program provides the most precise data for climate research, weather forecasting and land and ocean observation worldwide.

One example is the development of a high-precision spectrometer grating for the near-infrared channel (685-773 nm) of the Sentinel-5 satellite. This grating was specially developed for measuring trace gas concentrations such as ozone, nitrogen dioxide and methane. Highest diffraction efficiency and low polarization dependence ensure the most accurate measurement results.

From 2013-2025, the GAIA space probe was on its way to map several billion stars in the Milky Way with unprecedented accuracy using astrometry, photometry and spectroscopy. The result was the most precise and comprehensive star atlas that humans have ever had at their disposal. With the help of this scientific machine, astronomers were not only able to improve models of our solar system in more than 10,000 scientific papers, but also revolutionize our understanding of the origin and development of our home galaxy. On board is a spectrometer for measuring the so-called redshift. This is used to determine the direction and speed of movement of stars. One component of the spectrometer is a Fraunhofer IOF nano-optical grating with outstanding properties.

Fraunhofer IOF developed and built the high-precision RVS spectrometer grating for GAIA, which plays a central role in measuring the speed of movement of stars. The grating is based on an innovative nanostructure that enables light to be diffracted with maximum efficiency and precision. The structure consists of binary meta-atoms whose lateral dimensions are below the wavelength of light.

The grating was made of silica glass and produced using high-resolution electron beam lithography and reactive ion etching processes. The grating period is 3.1 µm, and the usable area measures 205 mm x 155 mm. With a wavefront error of less than 8 nm RMS and a high diffraction efficiency, it was crucial for the success of the mission. As a metastructure grating is probably the most productive metasurface ever made by humans.

The Fraunhofer IOF has developed a high-precision computer-generated hologram (CGH) for the Extremely Large Telescope (ELT), which is used to measure the world's largest convex mirror, the 4.2-meter M2 mirror. The CGH was produced on a quartz glass substrate using electron beam lithography and achieves an exceptional wavefront accuracy of just 5.34 nm (RMS). Only this precision enables the exact testing and optimization of the mirror surface, without which the telescope would not work. With this technology, the IOF is making an important contribution to the realization of the largest telescope for the visible and infrared spectral range.

In the PhoQuant project, Fraunhofer IOF is developing photonic quantum computer chips that use light particles (photons) as qubits. At the heart of this technology is a waveguide chip made of lithium niobate (LNOI), which is equipped with Mach-Zehnder interferometers. These enable the precise control and modulation of light signals. They are manufactured using scalable semiconductor production technologies, which makes it possible to integrate many computing units on a single chip. The aim of the project is to create a new photonic computer architecture that supports industrial applications such as research into new materials.

Markets and Applications for Micro- and Nanooptics

Are:

• Aerospace
• Mobility and Automotive
• Consumer Electronics
• Quantum Communication, Computing and Imaging
• Design and Lighting
• Optical Sensor Systems and Remote Sensing
• Defense and Security
• Industrial Production
• Laser Technology
• Science and Astronomy