Two of the most successful microresonator concepts are the vertical cavity surface emitting laser (VCSEL), comprising a vertical cavity of highly reflective DBRs sandwiching an active layer, and the distributed feedback (DFB) laser, where a periodic optical grating selects laser modes from an active waveguide (WG) layer. Here, an organic microcavity is coupled with in-plane periodic photonic wires or dots to facilitate a coherent interaction between waveguided and vertically emitting modes as well as creating an additional in-plane confinement. The vertical positioning of such patterning plays a crucial role in the observable features. While embedding metallic or dielectric wires directly in the cavity layer leads to a strong lateral confinement as well as the observation of photonic Bloch states [1,2], the deposition of the full VCSEL stack on top of a periodic grating reveals novel features. In such a device, we demonstrate the coherent coupling between parabolic VCSEL and linear WG modes in the angle-resolved far field emission. In this system, lasing occurs not only at the VCSEL parabola apex but also at points of hybridization, when the dispersion of modes cross, showing a drastically enhanced in-plane coherence [3]. The coherent coupling of two conceptually different devices with perpendicular propagation directions paired with the macroscopic coherence facilitate a multitude of new applications.
[1] Adv. Opt. Mater. 2(8), 746 (2014)
[2] Phys. Rev. Appl. 3, 064016 (2015).
[3] Adv. Opt. Mater. under review (2016).
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