Optical vortex solitons in a defocusing saturable medium are analyzed in the framework of the (2 1 1)-dimensional generalized nonlinear Schrödinger equation. Stationary, radially symmetric localized solutions with nonvanishing asymptotics and a phase singularity (vortex solitons) are found numerically for the varying saturation parameter. Relaxation of some localized initial profiles (e.g., vor...

III-nitride-based laser diodes (LDs) are compact and efficient source of highly coherent continuous wave light for optoelectronic applications in the short-wavelength range (λ ∼ 400 nm). High peak-power and short-pulse generation in this spectral range has not yet been attempted and is of particular interest for applications such as, e.g., the next-generation of high-density optical data storag...

We discuss mode-locking of low-gain solid-state lasers using a semiconductor saturable Bragg reflector structure. This recently developed low-loss mode-locking device consists of a single quantum well which acts as a saturable absorber incorporated into a high-reflectivity Bragg mirror. Highly stable mode-locking in solid-state lasers results from an ultrafast transient reflectivity in the devi...

The ultrafast saturable absorption in graphene is experimentally and theoretically investigated in the femtosecond (fs) time regime. This phenomenon is well-modeled with valence band depletion, conduction band filling and ultrafast intraband carrier thermalization. The latter is dominated by intraband carrier-carrier scattering with a scattering time of 8 ( +/- 3) fs, which is far beyond the ti...

Mathematical description of a passively Q-switched laser and the way it works are presented. Both theoretical and experimental model of this laser have been worked out. Moreover, numerical analysis of saturable absorber influence on laser efficiency was made. It is the saturable absorber characterized by excited state absorption (ESA) that has been taken into account. The optimization procedure...

We present a quantum-mechanical treatment of fluctuations and saturable absorption in mesoscale lasers. The time evolution of the density matrix is obtained from numerical integration and field-field and intensityintensity correlations are calculated to obtain steady-state linewidth and photon statistics. Inclusion of a saturable absorber in the otherwise homogeneous medium is shown to suppress...

Abstract Metal–organic frameworks (MOFs) are widely explored owing to their excellent nonlinear optical (NLO) properties. However, researchers have mainly focused on designing new structures of MOF crystals adjust the NLO response while ignoring influence number metal–ligand coordination bonds properties MOFs. In this study, numbers MOFs is studied for first time. Herein, with different numbers...