Photonic Landscape Engineering for Tailor-Made Coherent Emission from Strongly-Coupled Organic and Biological Fluorophores

• Applicant: Dr. Andreas Mischok
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2018 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 404587082

Microcavities (MCs) offer a flexible playground to study photon and polariton dispersion in a tunable potential landscape. In vertical MCs, confined photons exhibit a parabolic dispersion relation and in turn behave similarly to other parabolic particles such as free electrons, albeit with an approx. 10^-5 times smaller effective mass, leading to very low condensation and/or lasing thresholds. By adding a thin interlayer inside of an organic MC, one can observe red-shifted photonic states, shifting the cavity potential to lower energies. Consequently, patterning this thin layer enables a manipulation of the potential landscape and creates polariton wells and lattices in 2D and 3D. In the course of this fellowship, coherently coupled emission from multiple potential wells shall be utilized to showcase both the strong interaction of polaritons from different points of the lattice as well as the macroscopic coherence of light in the real space.Accessing the patterning parameters then gives a further degree of freedom in engineering the k-space emission of such microlasers. By changing the lattice constant in periodic photonic wires, as well as square and hexagonal dot arrays, a remarkable control over the lasing modes will be exerted, enabling almost arbitrary emission angles and mode shapes. The incorporation of controlled defect states is expected to further improve the performance of strongly coupled devices. The favourable properties of organic dyes enable a unprecedented scope of possibilites both for fundamental and applied research here. In particular, highly controlled tunable polariton lasers, dispersion-free polariton organic light emitting diodes and narrowband photodetectors can be envisioned.

• DFG Programme: Research Fellowships
• International Connection: United Kingdom
• Host: Professor Dr. Malte Gather