Ultralow-threshold quasi-CW lasing from FAPbBr3 perovskite first-order DFB laser.

Metal halide perovskites are emerging materials for integrated photonics. Here we report a quasi-CW pumped ultra-low ASE/lasing threshold formamidinium lead bromide (FAPbBr3) laser. The laser achieved stable lasing at 555 nm with a full width at half maximum (FWHM) of 0.6 nm, showing a low lasing threshold of 22.6 μJ cm-2 under 3.5 nanosecond quasi-CW excitation at room temperature. The material also showed an ultra-low ASE threshold of 46 μJ cm-2 under the same pumping condition. Through polymer doping, we showed that the material's performance can be improved by increasing bimolecular recombination rate with reduced grain size.