Figure 17.

(a) The normalized absorption (black) and fluorescence spectrum (red) of BODIPY-Br dispersed in a transparent polystyrene matrix. The chemical structure is shown in the insert. (b) Amplified spontaneous emission from a 186 nm thick film of the BODIPY-Br (39, Scheme 2) dispersed in a polystyrene matrix and deposited on a quartz substrate. A threshold is observed at a pump fluence of 104 μJ cm⁻² with a peak forming at 589 nm (dashed–dotted line). The dotted line indicates the polariton emission from the microcavity, while the large dashed line indicates the fluorescence emission peak shown in (a). Reproduced from Ref. [105] with permission from 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim, Germany.