title: Pump spot size dependent lasing threshold in organic semiconductor DFB lasers fabricated via nanograting transfer.
abstract: Optically excited organic semiconductor distributed feedback (DFB) lasers enable efficient lasing in the visible spectrum. Here, we report on the rapid and parallel fabrication of DFB lasers via transferring a nanograting structure from a flexible mold onto an unstructured film of the organic gain material. This geometrically well-defined structure allows for a systematic investigation of the laser threshold behavior. The laser thresholds for these devices show a strong dependence on the pump spot diameter. This experimental finding is in good qualitative agreement with calculations based on coupled-wave theory. With further investigations on various DFB laser geometries prepared by different routes and based on different organic gain materials, we found that these findings are quite general. This is important for the comparison of threshold values of various devices characterized under different excitation areas.
authors: Xin
authors: X
authors: Liu
authors: Sönke
authors: S
authors: Klinkhammer
authors: Ziyao
authors: Z
authors: Wang
authors: Tobias
authors: T
authors: Wienhold
authors: Christoph
authors: C
authors: Vannahme
authors: Peter-Jürgen
authors: PJ
authors: Jakobs
authors: Andreas
authors: A
authors: Bacher
authors: Alban
authors: A
authors: Muslija
authors: Timo
authors: T
authors: Mappes
authors: Uli
authors: U
authors: Lemmer