Ultrawide tuning range in doped organic solid-state lasers

We report on the tunability of 4-(Dicyanomethylene)-2-methyl-6-(julolidin-4-$yl$ -vinyl)-$4H$ -pyran (DCM2)-doped guest-host organic lasers. As host materials Tris-(8-hydroxy-quinoline)aluminum $\left(\mathrm{Al}{\mathrm{q}}_3\right)$ , 4,$4^{\prime }\text{‐}N,N^{\prime }$ -dicarbazole-bipheny1 (CBP), and $N^{\prime }N$ -di(1-naphthyl)-$N,N^{\prime }$ -diphenyl-1,$1^{\prime }$ -diphenyl-4,$4^{\prime }$ -diamine (NPD) are used. The largest tuning range was observed in the $\mathrm{Al}{\mathrm{q}}_3:\mathrm{DCM}2$ film with $115.3\mathrm{nm}$ between 597.8 and $713.1\mathrm{nm}$ . In CBP:DCM2, a tuning range of $85\mathrm{nm}$ was measured, whereas in NPD:DCM2 only one laser wavelength at $624.4\mathrm{nm}$ could be observed. When comparing the pump energies, we observed considerably lower threshold energy densities in $\mathrm{Al}{\mathrm{q}}_3:\mathrm{DCM}2$ and CBP:DCM2 compared to NPD:DCM2.