Fig. 1. (a) Raman spectrum of b-AsP nanosheets. (b) AFM image and representative height profile of b-AsP nanosheets.

Fig. 2. (a) Transmittance versus incident optical power intensity of b-AsP SA. (b) Time-resolved response of b-AsP SA.

Fig. 3. (a) Experimental setup of PQS. (b) The ratio of output powers to absorbed pump powers under the CW and PQS operations. (c) The emission wavelength of the CW and PQS lasers. (d) Pulse durations and repetition rates versus absorbed pump powers. (e) Pulse energy and peak power versus absorbed pump power. (f) The pulse trains and the shortest pulse profiles with different time scales.

Fig. 4. (a) Experimental setup of CWML laser. (b) CWML laser spectrum. (c) Autocorrelation trace. (d) The frequency spectrum with a wide and narrow span. (e) Pulse trains at the maximum pump power.