Fig. 7

a Laser emission on DFBs based on F8BT upon 113° bending (red), 61° (blue), 41° (brown), and 0° (orange). The inset sketch illustrates a DFB under a β bending angle. b Integrated emission intensity as function of pump fluence for different bending angles: 113° (squares), 61° (circles), 41° (up-triangles), and 0° (down-triangles). Lasing thresholds as a function of bending angle are shown in the inset