1.6 µm tunable and switchable single-frequency erbium-doped fiber laser.

We present a tunable and switchable single-frequency (SF) erbium-doped fiber laser (EDFL) operating at 1.6 µm. For the first time, a multichannel Sagnac filter, a "θ" sub cavity, and a saturable absorber (SA) have been combined to achieve SF operation of single- and dual-wavelength tunability as well as single-dual-triple-wavelength switching.

Polarization-Dependent Anisotropy of LIPSSs' Morphology Evolution on a Single-Crystal Silicon Surface.

Utilizing the principle of laser-induced periodic surface structures (LIPSSs), this research delves into the morphological evolution of single-crystal silicon surfaces irradiated by a near-infrared picosecond laser through a scanning mode. With the increase in laser energy density, the nanostructure morphology on single-crystal silicon surfaces induced by incident lasers with different polarization directions sequentially produces high spatial-frequency LIPSSs (HSFLs) with a period of 220 nm ± 10 nm parallel to the laser polarization, low spatial-frequency LIPSSs (LSFLs) with a period of 770 nm ± 85 nm perpendicular to the direction of the polarization, and groove structures. Furthermore, by varying the angle between the laser polarization and the scanning direction, the study examined the combined anisotropic effects of the laser polarization scanning direction angle and the laser polarization crystal orientation angle on the genesis of LIPSSs on single-crystal silicon (100) surfaces.

Mechanism of noise-like pulse in all-normal dispersion all-fiber laser based on nonlinear polarization rotation.

We investigate the mechanism of changing the polarization state to generate noise-like pulses (NLPs) in the all-normal dispersion (ANDi) all-fiber laser based on nonlinear polarization rotation (NPR). Numerical simulations show that the intracavity positive and negative feedback states change with the polarization state, the peak power of the pulse will be clamped when the negative feedback comes into play, thus facilitating the transition from dissipative soliton (DS) to NLP. Experimentally, the observation of wavelength switching and transition between DS and NLP by simply adjusting the polarization state matches the numerical simulation results.

All-normal dispersion widely tunable dual-wavelength mode-locked fiber laser based on NALM.

We experimentally and numerically demonstrate the all-normal dispersion (ANDi) ytterbium (Yb)-doped fiber laser based on nonlinear amplifying loop mirror (NALM) mode-locked, which allows tunable single-wavelength and dual-wavelength outputs. The pulses tuning ranges of the dual-wavelength are from 1032.24 nm to 1053.

Monolithic Saturable Absorber with Gallium Arsenide Nanowires Integrated on the Flexible Substrate for Optical Pulse Generation.

In this work, we demonstrated a kind of flexibly monolithic saturable absorber (SA) with GaAs nanowires (NWs) on polyimide (PI) plastic substrate for broadband optical modulation at 1.0 and 1.5 µm, separately.

170-W Nd:YAG InnoSlab laser at 1319 nm.

In this paper, a continuous-wave Nd:YAG InnoSlab laser at 1319 nm with high output power and high beam quality is demonstrated. The maximum output power of 170 W at 1319-nm single wavelength is obtained with an optical-to-optical efficiency of 15.3% from absorbed pump power to laser output and the corresponding slope efficiency of 26.

Observation of four self-sweeping regimes in a single-mode bi-directional ytterbium-doped fiber ring laser.

In this work, for the first time, four self-sweeping regimes in a single-mode bi-directional ytterbium-doped fiber ring laser are observed by adjusting the polarization controller (PC): normal self-sweeping, reverse self-sweeping, mixed state, and wavelength stop state. In addition, regulating the PC can artificially selectively make the laser operate in normal self-sweeping or reverse self-sweeping within a certain pump power range, and their self-sweeping characteristics (e.g.

Sideband-free tunable and switchable dual-wavelength mode-locked fiber laser based on the Lyot filter and spontaneous radiation peaks.

We demonstrate a compact tunable and switchable dual-wavelength fiber laser based on the Lyot filtering effect and the spontaneous radiation peaks of gain fiber. By introducing a period of polarization-maintain Er-doped fiber (PM-EDF), stable dual-wavelength pulses can operate in both the anomalous dispersion region and the normal dispersion region. The corresponding repetition frequency difference of the dual wavelengths has excellent stability while the relative center wavelength can be adjusted in the range of 5 nm to 13 nm.

Generating narrow bandwidth pulses in a hybrid mode-locked fiber laser.

We demonstrate for the first time, to our knowledge, an all-fiber erbium-doped mode-locked laser in which mode-locking (ML) is realized by the combination of nonlinear polarization rotation and a saturable dynamic filtering effect, thereby generating nearly transform-limited ultrashort pulses with a pulse duration and spectral width of 45.2 ps and 0.0775 nm, respectively.

Stable-, period-N- and multiple-soliton regimes in a mode-locked fiber laser with inconsistently filtered central wavelengths.

We systematically study the stable-, period-N- and multiple-soliton regimes in an Erbium-doped fiber laser effectively mode-locked by nonlinear polarization rotation technique. In the stable mode-locked regime, an invariant soliton with 497 fs pulse duration and 6.9 nm optical spectrum are obtained.

Asymmetric localization and symmetric diffraction-free transmission in synthetic photonic lattice with anti-parity-time symmetry.

We study, to the best of our knowledge, the first observations of light propagation in synthetic photonic lattice with anti-parity-time symmetry by tuning the gain or loss of two coupled fiber rings alternatively and corresponding phase distribution periodically. By tuning the phase and the wave number in the lattice, asymmetric transmission of the light field can be achieved for both long and short loops when ≠/2 ( is an integer). Further investigations demonstrate that asymmetric localization of the light field in the long loop and symmetric diffraction-free transmission in two loops can both be realized by changing these two parameters.

Observation of reverse self-sweeping effect in an all-polarization-maintaining bidirectional ytterbium-doped fiber laser.

In this article, we report, to the best of our knowledge, the first observation of the reverse self-sweeping phenomenon in an all-polarization-maintaining bidirectional ytterbium-doped fiber laser. Conventional behaviors, including the dependence of sweeping range, sweeping rate and average pulse repetition rate on the pump power, can be observed in our fiber laser. Two couplers with ratio of 50/50 and 10/90 are respectively employed as the output coupler in fiber laser, which generates the reverse self-sweeping phenomenon for comparison.

Black phosphorus flakes covered microfiber for Q-switched ytterbium-doped fiber laser.

We demonstrate a passively Q-switched ytterbium-doped fiber laser based on black phosphorus (BP) flakes covered microfiber. The BP saturable absorber is fabricated by sandwiching a microfiber between two pieces of polydimethylsiloxane supported BP flakes film, which is prepared by the mechanical exfoliation method. In this case the BP flakes can be well protected from the action of air and moisture.

Slope efficiency over 30% single-frequency ytterbium-doped fiber laser based on Sagnac loop mirror filter.

A high-slope-efficiency single-frequency (SF) ytterbium-doped fiber laser, based on a Sagnac loop mirror filter (LMF), was demonstrated. It combined a simple linear cavity with a Sagnac LMF that acted as a narrow-bandwidth filter to select the longitudinal modes. And we introduced a polarization controller to restrain the spatial hole burning effect in the linear cavity.