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Michael Scharrer

Publications and source records attributed to Michael Scharrer.

2 recordsLinked to original sources
arXiv2009

Five-Fold Reduction of Lasing Threshold near the First $ΓL$-Pseudogap of ZnO Inverse Opals

We report room temperature lasing in ZnO inverse opal photonic crystals in the near-ultraviolet (UV) frequency. We observe random lasing due to disorder in the structures when the photonic pseudogaps are located away from the ZnO gain spectrum. Tuning the first $ΓL$-pseudogap to the gain peak leads to a five-fold reduction in lasing threshold and frequency shift of lasing modes due to the enhanced confinement of light.

physics.optics↗
arXiv2008

Photoluminescence modification by high-order photonic band with abnormal dispersion in ZnO inverse opal

We measured the angle- and polarization-resolved reflection and photoluminescence spectra of ZnO inverse opals. Significant enhancement of spontaneous emission is observed. The enhanced emission not only has good directionality but also can be linearly polarized. A detailed theoretical analysis and numerical simulation reveal that such enhancement is caused by the abnormal dispersion of a high-order photonic band. The frozen mode at a stationary inflection point of a dispersion curve can strongly modify the intensity, directionality and polarization of spontaneous emission.

physics.optics↗