We demonstrated a widely tunable Tm-doped mode-locked all-fiber laser, with the widest tunable range of 136 nm, from 1842 to 1978 nm. Nonlinear polarization evolution (NPE) technique is employed to enable mode-locking and the wavelength-tunable operation. The widely tunable range attributes to the NPE-induced transmission modulation and bidirectional pumping mechanism. Such kind of tunable mode...

We suggest analytic estimates for the Q-switching instability boundary of the continuous-wave mode-locking regime domain for a ring cavity semiconductor laser. We use a differential delay laser model that allows to assume large gain and loss in the cavity, which is a typical situation for this laser class. The slow saturable absorber approximation is applied to derive a map that describes the t...

We report the first mode-locked fiber laser using a chalcogenide microwire as the nonlinear medium. The laser is passively mode-locked with nonlinear polarization rotation and can be adjusted for the emission of solitons or noise-like pulses. The use of the microwire leads to a mode-locking threshold at the microwatt level and shortens the cavity length by 4 orders of magnitude with respect to ...

A novel approach to monitoring the laser injection-locking (IL) state is proposed and verified using side-mode suppression ratio (SMSR). In a photonics experiment for IL, an optical spectrum analyzer with conventional criterion of 35-dB SMSR conventionally used detect locking Fabry–Pérot (FP) multiple longitudinal modes external master one mode. Since not always sufficient condition, we propose...

Completely self-starting and stable operation of a Kerr-lens mode-locked Ti:sapphire laser was realized in both picosecond and femtosecond regimes. The cavity has a symmetric X configuration with soft aperturing. Enhanced Kerr nonlinearity and reduced backscattering effects were thought to be key to obtaining stable self-starting self-mode-locked operation from 765 to 815 nm for the picosecond ...

The impact of upper state lifetime and spatial hole burning on pulse shape and stability in actively mode locked QCLs is investigated by numerical simulations. It is shown that an extended upper state lifetime is necessary to achieve stable isolated pulse formation per roundtrip. Spatial hole burning helps to reduce the pulse duration by supporting broadband multimode lasing, but introduces pul...

An optical pulse injection locking technique is employed to generate shorter pulses from a passively modelocked quantum dot laser. The optical pulse injection locking enables the coherent addition of phaselocked longitudinal mode groups from two separate modelocked lasers without the use of stabilisation control loops, thus increasing the spectral bandwidth output resulting in optical pulses wi...