On 16th of October, we would like to invite you to our next special innoFSPEC seminar given by Prof. Morten Bache from DTU Copenhagen.
In case of questions and for further information, please contact Dr. Stefano Minardi ().

• speaker: Prof. Morten Bache
• affiliation: DTU Copenhagen
• title: Ultrafast nonlinear optics with quadratic nonlinearities: prospects for integrated photonics
• location: Leibniz-Institute for Astrophysics (AIP), An der Sternwarte 16, 14482 Potsdam; Schwarzschild house, seminar room
• date & time: Monday, 16th of Oct 2017, 2-3 pm

Abstract: Crystals with quadratic nonlinearities have great potential for ultrafast nonlinear interaction as they offer a parametrical control over the nonlinearity. By operating with a finite phase-mismatch both the sign and strength of the nonlinear phase shifts can be changed. At DTU Fotonik we have over the past decade exploited this to generate a negative nonlinear refractive index. This gives filament-free interaction of high-energy self-defocusing solitons in bulk crystals, and all the associated aspects of a soliton-based supercontinuum: soliton fission, dispersive wave formation, Raman self-frequency shifts and self-steepening. An important recent experiment showed that the supercontinuum content can be parametrically controlled as the soliton though the quadratic nonlinearities can experience phase matching with a dispersive wave deep into the blue and mid-IR, by respectively sum- and difference frequency generation. This gives a new dimension to the control over the spectral content in a supercontinuum, and this has interesting potential applications for on-chip waveguides for integrated photonics as it allows to coherently extending comb lines to new regions. I will review these possibilities at the end of the talk, where results from integrated photonics platforms using lithium niobate, silicon nitride and aluminum nitride are discussed.

About the speaker: Morten Bache is an associate professor, and the Ultrafast Nonlinear Optics team leader in the Ultrafast Infrared and Terahertz Science group, at DTU Fotonik, Technical University of Denmark, www.fotonik.dtu.dk/ultrafast. He holds key results on theory, simulation and experiments in ultrafast nonlinear optics in quadratic nonlinear crystals, optical fibers and waveguides.