Ultrafast fiber lasers have been serving as an ideal playground for spreading the extensive industrial applications and exploring optics nonlinear dynamics.Here, we report a bidirectional laser scheme validating possibility of multiplexed system, which is passively mode-locked by polarization rotation (NPR) technique.In particular, proposed consists one main cavity two counter-propagating branches with different dispersion distributions.Thus, formation mechanisms are introduced into lasing...

Rapid progress in real-time spectroscopy uncovers the spatio-spectral scenarios of ultrashort pulses dissipative systems. Varieties transient soliton dynamics on different timescales have been revealed. Here, we report an experimental observation stationary and pulsating vector solitons a nonlinear multimode interference (NL-MMI) based fiber laser with net normal dispersion. Polarization non-discrimination NL-MMI mode-locking facilitates trapping process. Two orthogonally polarized...

Physics phenomena of multipulse compounds have enriched the life ultrashort pulses beyond traditional pulse singlets in passively mode-locked fiber lasers. By developing a near zero-dispersion laser, we report on generation dispersion-managed soliton (DMS) molecules. During propagation laser cavity, broadband DMSs experience breathing process (i.e., periodic compression and stretch width), which facilitates various molecule evolutions from singlets. In particular, tightly bound DMS pairs,...

Recent progress in time-stretch spectroscopy accelerates the exploration of ultrafast dynamics mode-locked lasers through mapping spectral information into time domain. Here, we report on real-time access to coexistence soliton singlets and molecules an all-fiber laser by a 45° tilted fiber grating. By virtue dispersive Fourier transform process, pulse trains under multi-pulse states can be resolved. It is identified that coexist one cavity roundtrip with different assembling forms. In...

We report on the generation of L-band noise-like pulses (NLPs) in a bidirectional mode-locked fiber laser. Benefiting from absence isolator and in-band absorption erbium-doped fiber, at waveband over 1600 nm are delivered this oscillator. With appropriate settings, conventional solitons can evolve into NPLs both clockwise counter directions, which validated by sideband-free spectral shape distinguishable autocorrelation trace. In addition, it is experimentally found that NLP tends toward...

Recent research on nonlinear multimode interference (NL-MMI) based mode-locking method provides a new approach for ultrafast all-fiber lasers. Here, we report the polarization dynamics of group velocity locked vector solitons (GVLVSs) and noise-like pulses (NLVPs) in graded-index fiber (GIMF) laser. Due to non-polarization sensitive characteristic NL-MMI, emitted automatically evolve into multi-pulse complexes constituting two orthogonally polarized components. Beyond traditional resolved...

We report an experimental observation of wavelength tuning and bound states in fiber lasers. A Mach-Zehnder interferometer (MZI) is adopted as intra-cavity tunable filter to realize large-scale bandwidth controlling. By finely manipulating the MZI polarization state, continuous wavelength-tunable operation from 1550.7 nm 1580.8 achieved. Meanwhile, spectral varying 1.85 3.41 also controlled by broadening free spectrum range (FSR) MZI. Additionally, with modest adjustment, both tightly...

We propose and demonstrate a quasi-distributed fiber sensor based on cascaded microfiber Fabry-Perot interferometers (MFPIs) for simultaneous refractive index (RI) temperature measurement. By employing MFPI that is fabricated by taper-drawing the center of uniform Bragg grating standard into section microfiber, dual-parameters including RI can be detected through demodulating envelop resonant wavelength reflection spectrum MFPI. Then, wavelength-division-multiplexing applied to realize...

In this letter, we design a wavelength-switchable single-longitudinal-mode (SLM) fiber laser based on reflective 8-shaped microfiber resonator (8-MR). By cascading the 8-MR with Fabry-Pérot interferometer, Vernier effect can be generated for SLM filtering. Due to nature of 8-MR, section unpumped erbium-doped directly inserted in front further suppress-mode competition. A lasing spectrum central wavelength 1564.685nm, and sidemode suppression ratio as high 56.6 dB is achieved. Stability test...

Recent discovery on scalar-vector features of ultrashort pulses sheds new light the polarization dynamics ultrafast fibre lasers. Here, we report generation scalar and vector solitons in a bidirectional laser based nonlinear rotation (NPR). Through introducing different evolving mechanisms into counter-propagation branches, respectively approaches scalar-soliton regime vector-soliton clockwise counterclockwise directions. It is found that strong local birefringence facilitates energy to flow...

We demonstrate numerically that in a three-level Λ-type atomic system, by using two laser pulses, it is able to create arbitrary coherent superposition of the lower levels via varying linear chirp rate pump pulse case two-photon detunings. The underlying physics phenomenon given analysing Hamiltonian system on basis dressed states. find due existence anticrossings closely spaced

We report on the multi-state soliton generation in a chirped fiber Bragg grating (CFBG) based bidirectional mode-locked laser. In particular, θ-shape associate cavity is designed to introduce reverse dispersion distributions counter-propagation directions through incorporating reflection of CFBG into lasing oscillator. With relatively compact configuration, clockwise (CW) and counterclockwise (CCW) are managed large anomalous normal regimes, respectively. Consequently, conventional solitons...

Dispersion distribution and optical gain dynamics introduce vivid pulse evolution in fiber lasers. Here, we report on a multi-output laser mode-locked by nonlinear polarization rotation (NPR) net normal-dispersion regime. In particular, the asymmetry settings of parameters can spectral reshaping breathing process at different output ports. Both transformation from gain-guided dissipative solitons (GGDSs) to similaritons periodic stretching compression widths are experimentally observed....

The action of freeze–thaw (F–T) cycles claystone exerts a profound impact on the slope stability open-pit mines in water-rich regions. Microstructural changes are observed as crucial factor determining hydraulic characteristics and mechanical behaviors claystone. present work integrates micro-X-ray computed tomography (Micro-CT) scanner, equipped with image processing three-dimensional (3D) reconstruction capabilities, employed to observe microstructure under varying numbers F–T (0, 10, 20,...

High sensitive strain sensor of hundred ηε magnitude realized by combining coherent OTDR detection with microstructures based fiber is proposed and demonstrated, promising long distance fully-distributed sensing no dead zone.

In this paper, two kind of microwave absorbers based on local resonance artificial periodic structures i.e. metamaterials. When irradiated by plane wave with adaptive polarization, there will be electric or magnetic in the To absorb energy been reflected, resistive sheets are used like conventional Salisbury screen. The absorber is very thin and easy to fracture. relevant features its electrical thickness small while compared operating wavelength, absence a metallic backing, which common...

We report a distributed dynamic pressure sensor system based on fiber microstructure arrays packaged with high elastic polymer, achieving spatial resolution of 1cm and sensitivity 1.665nm/Mpa.

We propose and demonstrate a distributed fiber sensor based on cascaded microfiber Fabry-Perot interferometers (MFPI) for simultaneous refractive index (SRI) temperature measurement. By employing MFPI which is fabricated by taper-drawing the center of uniform Bragg grating (FBG) standard into section microfiber, dual parameters including SRI can be detected through demodulating reflection spectrum MFPI. Further, wavelength-division-multiplexing (WDM) applied to realize dual-parameter using...

Based on negative refraction circuit theory, a novel broadband Wilkonson balun which is constructed by conventional transmission line with lumped-element series capacitors and shunt inductors proposed in this paper. And the realization method of broadening impedance circular polarization axis ratio bandwidth analyzed. A CP microstripe antenna using central frequence 1.40GHz , achieved 52.37%, The VSWR always below 2 bandwidth.

Atom-like behaviors make the bound solitons akin to molecules. Here, we report on experimental observation of soliton molecule vibration in mode-locked fiber lasers with time-stretch technique deepen our understanding complexes.

We report the observation of soliton molecules in a WS2 fiber laser. Experimentally, tightly bound and bunch are respectively obtained which unveils dynamics complexes lasers.