Fig. 1: Mode-locked laser based on pristine Bi2O2Se nanoplates.
From: High output mode-locked laser empowered by defect regulation in 2D Bi2O2Se saturable absorber
a Average output power of the CWML versus absorbed pump power. As the pump power increases, the mode-locked operating state transitions from continuous wave (CW) to Q-switched mode-locking (QML), and finally switches to CWML state. b Autocorrelation trace for ~587 fs duration. c Recorded frequency spectrum with narrow and wide (inset) spans. d Normalized differential transmission of Bi2O2Se nanoplates with different plasma treatment times at T = 300 K and F = 71.9 µJ/cm2. e Blue dots are the time evolution of the carrier density. The red (orange) line indicates the simulated temporal evolution of the free (trapped) carrier density using Eq. (1)(2). Inset: Schematic illustration of carrier trapping by defects and the subsequent defect-assisted Auger recombination.
