Fig. 1. Schematic of the band-gap-tailored random laser.

Fig. 2. Chemical structures of chiral agent S811, infrared absorbing material PBIBDF-BT, and laser dye PM597.

Fig. 3. Experimental setup for the NIR controlling random laser.

Fig. 4. (a) DSC curves of CLC-based S811 (30 wt.%) in E7 (70 wt.%) at heating/cooling rate of 1°C per minute; (b) LC textures recorded under crossed polarizers for the sample at 26°C and 30°C.

Fig. 5. Transmission spectra of CLC as functions of (a) temperature and (b) irradiation time at 850 nm.

Fig. 6. Random lasing emission (a) for smectic A state at ∼0.35  mJ pump intensity, and (b) for cholesteric state at ∼3  μJ pump intensity; the relation between the output intensity and the pump intensity for (c) smectic A state and (d) cholesteric state.

Fig. 7. Random lasing spectra of LCs at the cholesteric state at different NIR (850-nm) irradiation times.

Fig. 8. Random laser wavelength changes with time (× represents three major laser peaks of the RL with NIR irradiation. * represents three major laser peaks of the RL without NIR light).

Fig. 9. (a) Transmission spectra of CLC as a function of irradiation time of 940-nm NIR. (b) Bragg wavelength as a function of NIR irradiation time. (▪ 850-nm NIR irradiation on the sample; 940-nm NIR irradiation on the sample.)

Fig. 10. Stable random lasing wavelength for (a) different NIR irradiation wavelengths and (b) different concentrations of infrared absorbing material at 850 nm for 30 min.

Fig. 11. Stabilized wavelength of RLs changes with varying NIR irradiation power.