© AG Fallnich

In the research field of transverse modes, we develop laser concepts with which individual transverse modes and their superpositions can be selectively excited in laser resonators. One focus is on the ultrafast spatiotemporal dynamics that arise when several transverse modes are phase-locked. In addition, we investigate the connection between transversally and longitudinally mode-locked states and convert such beams into each other. We develop tools for generating structured light, which offer new degrees of freedom, for example for novel optical measurement methods. Learn more.

© AG Fallnich

In the research field of nonlinear Microscopy we develop and optimize methods for the generation of coherent Raman scattering signals in samples and for detecting the resulting signals. We exploit certain properties of the Raman scattering process and modify the light sources and beams used in such a way that background-free detection is possible. We also design adapted detectors with which we can detect the signal with low noise. This allows us to make Raman microscopy usable, for example for imaging in medicine or pharmacy. Learn more.

© AG Fallnich

We realize the nonlinear conversion of light in integrated waveguides, e.g., made of silicon nitride (Si₃N₄) or tantalum pentoxide (Ta₂O₅), or in photonic crystal fibers. We use their third-order nonlinearities in tunable optical parametric oscillators and investigate the Kerr effect and self-phase modulation for supercontinuum generation as well as the interactions between transverse modes in multimode waveguides. Our development of waveguide-based light sources enables to further reduce system size and the required pump energy compared to nonlinear fibers, and is a step towards efficient and widely tunable, purely chip-based light sources. Learn more.