In this work we demonstrate comprehensive studies on graphene oxide (GO) and reduced (rGO) based saturable absorbers (SA) for mode-locking of Er-doped fiber lasers. The paper describes the fabrication process both detailed comparison their parameters. Our results show, that there is no significant difference in laser performance between investigated SA. Both provided stable, mode-locked operation with sub-400 fs soliton pulses more than 9 nm optical bandwidth at 1560 center wavelength. It...

In this Letter, we demonstrate an all-polarization-maintaining, stretched-pulse Tm-doped fiber laser generating ∼200 fs pulses centered at 1945 nm. As a saturable absorber, graphene/poly(methyl methacrylate) composite was used. To the best of our knowledge, is first demonstration operation graphene-based 2 μm.

We report on the generation of dissipative solitons in an Er-doped fiber laser mode-locked by antimony telluride (Sb 2 Te 3) topological insulator near-zero dispersion regime. Layers Sb 3 were deposited a side-polished (D-shaped) using pulsed magnetron sputtering technique. Sub-170-fs pulses with 34-nm full width at half-maximum (FWHM) and 0.21 nJ pulse energy obtained from all-fiber, ring-shaped cavity after compression single-mode fiber.

We report a study on hybrid mode-locked fiber laser with two saturable absorbers: slow and fast, integrated in single device. Amorphous antimony telluride (Sb(2)Te(3)) layer was deposited side-polished to form the absorber due third order nonlinear susceptibility of Sb(2)Te(3). Additionally, an unsymmetrical design device causes polarization-dependent losses together polarization controller allows use evolution artificial fast absorber. Sub-200 fs soliton pulses 0.27 nJ pulse energy were...

In this paper, femtosecond pulse generation in an Er-doped fiber laser is reported. The passively mode-locked by antimony telluride (Sb2Te3) topological insulator (TI) saturable absorber (SA) placed on a side-polished fiber. Sb2Te3/chitosan suspension used to prepare the SA was obtained via liquid phase exfoliation from bulk Sb2Te3.Ultra-short 449 fs soliton pulses were generated due interaction between evanescent field propagated cladding and Sb2Te3 layers. optical spectrum centered at 1556...

In this work pulse generation in both the 1.5 and 2 μm spectral ranges using a graphene oxide (GO)-paper-based saturable absorber Er- Tm-doped fiber lasers is presented. The article describes fabrication method of GO paper its characterization. performance discussed detail. Stable, mode-locked operation provides 613 fs 1.36 ps soliton pulses centered at 1565.9 1961.6 nm lasers, respectively. Furthermore, scaling width, hence duration, by increasing number layers Er-doped laser described....

Abstract Actively mode‐locked lasers offer varying degrees of flexibility for a wider range applications than their passively modulated counterparts, due to capability electrically controlled ultrahigh repetition rate operation. Graphene based electrooptic modulators with unique advantages broad operation bandwidth and ultrafast speed are suitable light modulation in various optoelectronic applications. Here, an actively laser graphene modulator is reported the first time. The active...

We present a study on antimony telluride (Sb2Te3)-deposited side-polished fiber device as saturable absorber for Yb-doped mode-locked lasers. Thin layers of Sb2Te3 with variable length were deposited by pulsed magnetron sputtering technique. demonstrate measured characteristics the and show that it can be treated hybrid component - tunable polarizer absorption properties. The polarizing extinction ratio varies from 1.5 dB up to 17.1 increasing deposition. components employed in all-normal...

Abstract Antimony telluride (Sb 2 Te 3 ) is an intermetallic compound crystallizing in a hexagonal lattice with R-3m space group. It creates c lose packed structure of ABCABC type. As intrinsic semiconductor characterized by excellent electrical properties, Sb widely used as low-temperature thermoelectric material. At the same time, due to unusual properties (strictly connected structure), antimony exhibits nonlinear optical including saturable absorption. Nanostructurization, elemental...

Ultra-high-pulse-repetition-rate lasers are essential for a number of applications, including, e.g., optical communication and ablation-cooled material processing. Despite several techniques to generate pulses with gigahertz-range repetition rate, incorporating mainly short-length resonators, more widespread applications still limited by the lack robust, simple, cost-effective solution. Here, we report first time, best our knowledge, fully passive harmonic mode locking in an...

Significance Two-photon excitation (TPE) of retinal fluorophores with infrared light allows monitoring metabolic transformation the retina. TPE imaging can provide information about biochemical events that precede structural damage to retina and thereby accelerate development therapies against blinding diseases. While subcellular endogenous retinoids in pigment epithelium mice nonhuman primates has been achieved, human not fully realized due concerns safety identity molecular signals. We...

BackgroundNoninvasive assessment of metabolic processes that sustain regeneration human retinal visual pigments (visual cycle) is essential to improve ophthalmic diagnostics and accelerate development new treatments counter diseases. Fluorescent vitamin A derivatives, which are the chemical intermediates these processes, highly sensitive UV light; thus, safe analyses in humans currently beyond reach even most modern ocular imaging modalities.MethodsWe present a compact, 2-photon-excited...

We characterized and analyzed the effect of intracavity spectral filtering in Er:fiber laser mode-locked with a semiconductor saturable absorber mirror (SESAM). studied dispersive properties bandpass filters their influence on characteristics generated soliton pulses. Our analysis showed that various sideband structures were induced by filter dispersion profiles shaped through interaction wave. In addition, improved intensity phase noise significantly, we optimal conditions for both types...

We introduce a compact, all-fiber laser system with gain-managed nonlinear (GMN) amplified Yb:fiber oscillator and an integrated pulse-picker. The delivers 39 fs pulses peak powers of 0.83 MW adjustable pulse repetition rates (0.3–15 MHz), enabling multiphoton imaging at remarkably low excitation (as as 66 µW). Its design simplifies integration enhances experimental flexibility. Compatible two-, three-photon excitation, but also second harmonic generation microscopy, this versatile offers...

We introduce a compact, all-fiber laser system with gain-managed nonlinear (GMN) amplified Yb:fiber oscillator and an integrated pulse-picker. The delivers 39 fs pulses peak powers of 0.83 MW adjustable pulse repetition rates (0.3–15 MHz), enabling multiphoton imaging at remarkably low excitation (as as 66 µW). Its design simplifies integration enhances experimental flexibility. Compatible two-, three-photon excitation, but also second harmonic generation microscopy, this versatile offers...

We introduce a compact, all-fiber laser system with gain-managed nonlinear (GMN) amplified Yb:fiber oscillator and an integrated pulse-picker. The delivers 39 fs pulses peak powers of 0.83 MW adjustable pulse repetition rates (0.3-15 MHz), enabling multiphoton imaging at remarkably low excitation (as as 66 µW). Its design simplifies integration enhances experimental flexibility. Compatible two- three-photon excitation, but also second harmonic generation microscopy, this versatile offers...

We propose new graphene-chitosan solution as a saturable absorber for mode-locked Erbium-doped fiber laser. demonstrate stable, operation with pulse short 168 fs, which are the shortest pulses generated from an Er-doped laser use of graphene so far. Graphene-chitosan was obtained in soluble forms by addition acetic acid. The ring is able to generate optical solitons centered at 1554 nm wavelength 15.2 bandwidth and 63 MHz repetition rate.

A femtosecond frequency-doubled erbium-doped fiber laser with an adjustable pulse repetition rate is developed and applied in two-photon excited fluorescence microscopy. The all-fiber system provides the fundamental at 1560 nm wavelength 22 fs duration for second harmonic generation, resulting 1.35 nJ, 60 pulses 780 nm. adjusted by a picker unit built-in within amplifier chain, directly providing transform-limited any chosen between 1 12 MHz. We employed source to drive scanning microscope...

We report on the first application of an antimony telluride (Sb2Te3) thin film as a saturable absorber (SA) in microchip laser. The 3–15 nm-thick Sb2Te3 films were deposited glass substrates by pulsed magnetron sputtering and they studied SEM, X-ray diffraction, Raman optical spectroscopy. absorption was confirmed at 1.56 μm for ns-long pulses revealing low saturation intensity 0.17 MW/cm2. laser based Tm:GdVO4 crystal diode-pumped ~802 nm. In continuous-wave regime, this generated 3.54 W...

We present the performance of an all polarization-maintaining Erbium-doped fiber laser mode-locked by a multilayer graphene based saturable absorber. The cavity incorporates Martinez-type compressor, on transmission grating, which allows for continuous tuning net dispersion as well spectral filtering. By adjusting and bandwidth, we could operate in soliton, managed soliton absorber-limited pulse regimes. durations from ranged between 338 fs to 2.1 ps be operated at nearly constant output...

Droplet microfluidics disrupted analytical biology with the introduction of digital polymerase chain reaction and single-cell sequencing. The same technology may also bring important innovation in analysis bacteria, including antibiotic susceptibility testing at level. Still, despite promising demonstrations, lack a high-throughput label-free method detecting bacteria nanoliter droplets prohibits most interesting strains widespread use droplet technologies microbiology. We sensitive fast...

This paper presents the study on power scaling of an all-polarization maintaining (PM) fiber mode-locked laser using multilayer chemical vapor deposition graphene/poly(methyl methacrylate) composite as a saturable absorber by changing coupling ratio output coupler. Pulses with duration 148 fs were generated 10% coupler, which are shortest pulses obtained from erbium doped working in anomalous dispersion regime, additionally highest average 15.66 mW was achieved applying 70% All-PM resonator...

We report on the generation of 152-nJ Q-switched pulses in all-polarization-maintaining Er-doped fiber laser. The laser is passively modulated by antimony telluride (Sb2Te3) layer sputtered a surface side-polished order to exploit evanescent field interaction optically nonlinear material. cavity designed an extremely simple way comprising, addition fibers, only one component and saturable absorber, forming robust, compact, stable source short pulses. repetition rate might be tuned from 42...

In this paper, 80 fs pulse generation from an all-fiber Er-doped laser is reported. The mode-locked by a nonlinear polarization evolution mechanism in stretched-pulse regime. Ultrashort pulses are generated directly ring-shaped, dispersion-managed cavity with repetition rate of 31.9 MHz and 0.47 nJ energy. has design, including the dispersion compensation external compression stages, forming robust compact device.

Noninvasive imaging of endogenous retinal fluorophores, including vitamin A derivatives, is vital to developing new treatments for diseases. Here, we present a protocol obtaining in vivo two-photon excited fluorescence images the fundus human eye. We describe steps laser characterization, system alignment, positioning subjects, and data registration. detail processing demonstrate analysis with example datasets. This technique allays safety concerns by allowing acquisition informative at low...