OSC Colloquium: Harald Giessen, "3D Printed Complex Microoptics: Fundamentals and First Benchmark Applications"

We introduce 3d printed complex microoptics, spanning a range between a few micrometers up to 5 mm. Our lens system consists of aspherical multiplet lens systems which can give high numerical apertures with simultaneously excellent imaging properties over the entire field of view, even directly on an optical fiber tip. Combining several printed materials with different refractive indices and dispersions and the combination with diffractive elements allows for realization of micro-optical achromats or even apochromats which are aplanatic (no first- and third-order aberrations such as spherical aberration, astigmatism, coma, distortion etc.) and achromatic for 3 wavelengths (red, green, blue). We also demonstrate the direct printing of black resists, which results in aperture stops and blackened hulls.  

Atomic layer deposition yields antireflection coatings on all optical elements. Confocal surface profiling and wavefront interferometry demonstrate accuracies far better than lambda/20. In combination with high-resolution nanostructuring, also 3D holograms and metasurfaces can be included.  

We utilize these methods to demonstrate the smallest endoscope in the world, being able to pass through a root canal of a tooth, as well as ultracompact sensors with hologon or hypergon lenses or a set of Scheimpflug lenses with nearly 2pi steradian imaging solid angle. Illumination systems as well as holographic projectors and beam shapers directly on optical fiber tips are demonstrated. Coupling single quantum emitters or single photon detectors to single mode fibers is demonstrated. Furthermore, single-fiber optical trapping of polystyrene beads, live cells, or atomic systems becomes a possibility. 

Recently, we also demonstrated the use of 3D printed optics inside of a laser cavity, connecting a DBR mirror in a fiber with a solid state laser crystal.  

Harald Giessen graduated with a MSc in Physics from University of Kaiserslautern, Germany, and obtained his MSc and PhD in Optical Sciences in 1994 and 1995 from Optical Sciences Center, University of Arizona, working with Nasser Peyghambarian and Pierre Meystre. After a postdoc in 1996 at Max-Planck-Institute for Solid State Research in Stuttgart, Germany and an Assistant Professorship at University of Marburg, Germany, from 1997-2000 he became Associate Professor at University of Bonn, Germany. 

Since 2005 he is Full Professor and Director of the 4th Physics Institute and the Stuttgart Research Center of Photonics Engineering (SCoPE) at University of Stuttgart. His research deals with Ultrafast Nanooptics, Plasmonics, Metasurfaces and 3D Printed Micro-Optics. 

He is Fellow of Optica and has won an ERC Advanced Grant for Complex Plasmonics. In 2024, he was awarded the  Robert-Wichard-Pohl Prize of the German Physical Society for his pioneering work of 3D Printed Micro-Optics.