Defect‐State Lasing in Photonic Lattices of Metal–Organic Microcavities

Mona Kliem,Thomas Kiel,Hartmut Fröb,Andreas Mischok,Malin Kück,Karl Leo,Kurt Busch,Stefan Meister

doi:10.1002/adpr.202000116

Abstract

Photonic band structure engineering has developed into an important technique for controlling the emission and interaction of photons and polaritons in microcavities (MCs). Herein, lasing from defect states (DSs) in photonic Kronig–Penney structures embedded into metal–organic MCs is demonstrated. As compared to the more delocalized lasing states associated with photonic bands, these DSs exhibit improved lasing thresholds that lie even below the lasing threshold of the metal‐free cavity. The characteristics of these DSs are determined via full electrodynamic computations based on the discontinuous Galerkin time‐domain method.

Highlights

Photonic band structure engineering has developed into an important technique materials but extremely versatile when for controlling the emission and interaction of photons and polaritons in microcavities (MCs)
Most prevalent class of such defects is that of the distributed Bragg reflector (DBR) microcavities (MCs), where a 1D photonic crystal of alternating λ/4 layers of high and
For a better understanding of the design of the structures, the lasing dynamics of the organic MCs with varying internal silver metal gratings are computed with a discontinuous Galerkin timedomain (DGTD) method.[25]

Summary

Experimental Section

The investigated MC consisted two identical DBRs made of 21/2 pairs of silicon dioxide (SiO2) and titanium dioxide (TiO2) layers with quarter-wavelength thicknesses, i.e., dSiO2 % 110 nm and dTiO2 % 72 nm, respectively. Between the DBRs, a thin patterned silver layer (dAg % 33 nm) and the active layer with an optical thickness of λ/2 (see Figure 1a) were evaporated subsequently. The resulting structures were stripe-like patterns with period lengths p between 5.0 and 7.0 μm. Introducing a defect into the pattern leads to a distance between two adjacent silver stripes of d (see Figure 1b). Far-field emission was collected by a Â63 objective (NA 1⁄4 0.8) and projected on the entrance slit of a 0.6 m imaging spectrometer, recorded by a cooled charge-coupled device. The results of this measurement were angle-resolved emission spectra of high quality taken at ambient conditions

Theoretical Model

Results and Discussion

Above-Threshold Investigation

DGTD Computations

Conclusion