Investigation of Two Photon Absorption of Ligand-Modified CsPbBr Quantum Dots.

The characteristics and application of nonlinear absorption from CsPbBr QDs film with the ligand-modified strategy have been investigated in this work. By means of a near-infrared fs Ti:sapphire laser as a light source, the up-conversion emission of CsPbBr QDs film of around 518 nm revealed a quadratic increase with the pump intensity. Through the temperature-dependent up-conversion emission, we obtained the binding energy and longitudinal optical (LO) phonon energy of CsPbBr QDs film of around 58.

Repetition frequency pulling effects in asynchronous mode-locking.

Repetition frequency pulling effects are found to exist in asynchronous harmonic mode-locked fiber soliton lasers. The deviation frequency of asynchronous mode-locking is found to be dependent on the active modulation depth, not wholly determined by the difference between the intracavity active modulation frequency and the cavity harmonic repetition frequency. Transition from asynchronous to synchronous mode-locking will also occur when the modulation depth is above the threshold.