Gain-switching in CsPbBr3 microwire lasers

Gain-switching techniques offer a route to ultrafast lasing at the microscale. Here, 13 ps single-mode lasing from inorganic perovskite CsPbBr3 microwires is demonstrated and low transient saturated gain is identified as a significant limitation for further pulse shortening. All-inorganic perovskite microwire lasers, which have intrinsic high material gain and short cavity, especially favor the generation of ultrashort optical pulses via gain switching for various potential applications. Particularly, the ultrashort gain-switched pulses may extend perovskite microwires to previously inaccessible areas, such as ultrafast switches, and chipscale microcombs pumping souces in photonic integrated circuits. Here, we show 13.6-ps ultrashort single-mode green pulses from the gain-switched CsPbBr3 microwire lasers under femtosecond optical pumping. The gain-switching dynamics is experimentally investigated by a streak camera system. The excitation fluence dependences of pulse width, delay time and rise time of the output pulses show good agreements with the rate equation simulations with taking gain nonlinearities and carrier recombination ABC model into account. Our results reveal that perovskite microwire lasers have potential for ultrashort pulse generation, while the low transient saturated gain, which may result from the high transient carrier temperature under femtosecond pumping is a significant limitation for further pulse shortening.

Automated summary

This study demonstrates the generation of 13-ps ultrashort laser pulses through gain-switching techniques in inorganic CsPbBr3 microwires. The results reveal that the low transient saturated gain is a significant limitation for further pulse shortening. These perovskite microwire lasers, with high material gain and short cavity, have potential for various applications requiring ultrashort optical pulses.