Doped Fiber Laser Cavity Research Articles

Microsecond and nanosecond pulse initiator by Mo2Ga2C DSF saturable absorber (SA) with EDFL ring cavity

This paper elaborated the generation of microsecond and nanosecond pulse fiber laser using Mo2Ga2C coating onto DSF. The microsecond pulse commenced at the pump power of 39.826 mW and increased to 81.37 mW with a pulse width of 7.02 µs–5.92 µs. Meanwhile, the repetition rate showed measurements between 42.63 kHz to 64.6 kHz corresponding to the maximum pulse energy of 150.15 nJ. Besides that, the nanosecond pulse was generated with an additional length of 200 m for the SMF. The dual wavelength nanosecond pulse began at the pump power of 95.22 mW with a pulse width of 273.7 ns corresponding to the repetition rate of 961.8 kHz. Maximum pulse energy and maximum peak power were 8.75 nJ and 28.15 mW, respectively. The Mo2Ga2C coated DSF acted as the SA and was integrated into an erbium doped fiber laser cavity. The modulation depth of the Mo2Ga2C DSF SA was approximately 7.2 %.

Q-switched fiber laser operating at 1560 nm modulated by Cr3C2 film

Chromium carbide (Cr3C2), as a kind of transition metal carbides, has exhibited extraordinary optoelectronic properties and aroused enormous attention. However, few reports have been focused on the nonlinear properties and relevant devices. In this study, we first demonstrated a novel Cr3C2 saturable absorber (SA). Cr3C2 with an average size of 200 nm was prepared through a low temperature salt flux synthetic method. The Cr3C2-film SA exhibited high robustness and strong linear and nonlinear saturable absorption response at 1560 nm. As the Cr3C2 SA was inserted into the Er3+-doped fiber laser cavity, Q-switched pulses were generated with a central wavelength of 1560 nm. To the best of our knowledge, this was the first report on the optical nonlinearity of Cr3C2 as a Q-switcher for the near-infrared fiber laser. Our experimental results verified that the integrated Cr3C2-based device possessed great potential as a nonlinear optical medium for high-performance optical applications.

Passively Q-switched ytterbium doped fiber laser based on a weak-photothermal saturable absorber

Recently, plasmonic nanocrystals (NCs) have attracted much attention due to their wide applications in bioimaging, photothermal therapy and photonics devices. Compared to other metal NCs, copper NCs show a weak photo-thermal effect, which shows that the copper NCs are a good candidate for nonlinear optical materials. In this paper, we demonstrated a Q-switched fiber laser at 1 μm wavelength by using Cu1.8S NCs as a saturable absorber (SA). By incorporating the Cu1.8S SA into an ytterbium doped fiber laser cavity pumped by a 980 nm laser diode, stable passive Q-switching at 1038 nm was obtained for a threshold pump power of 63 mW. On gradually increasing the pump power from 64 mW to 160 mW, the repetition rate of a Q-switched laser increases from 25.7 kHz to 54.5 kHz and the pulse duration decreases from 6.7 μs to 2.33 μs. Our results showed that Cu1.8S NCs is an effective SA for constructing pulsed lasers with a broadband operating wavelength.

Passively Q-Switched and Mode-Locked Fiber Laser Based on a Zeolitic Imidazolate Framework-67 Saturable Absorber

Exploring new saturable absorber (SA) materials with excellent performance to achieve Q-switching and mode-locking operations is a hot topic in ultrafast laser research. The impressive specific surface areas, structural tunability, and high thermal and chemical stability of the zeolitic imidazolate framework (ZIF) materials make them promising candidates as high-performance SAs. In this work, we demonstrated the potential of the ZIF-67 SAs for ultrafast fiber laser applications. The nonlinear optical absorption characteristics of the ZIF-67 SAs at the telecommunication band were investigated by using the balanced twin-detector method. By incorporating the ZIF-67 SAs into the Er3+-doped fiber laser cavity, stable Q-switching and mode-locking operations were achieved. The research results are essential for promoting the application of novel hybrid nanomaterials in ultrafast lasers.

Gold nanoparticles PVA thin film as Q-switcher in neodymium doped fiber laser cavity

Gold nanoparticles PVA thin film as Q-switcher in neodymium doped fiber laser cavity

Gold nanoparticles film for Q-switched pulse generation in thulium doped fiber laser cavity

Gold nanoparticles film for Q-switched pulse generation in thulium doped fiber laser cavity

Mode-locked thulium/holmium-doped fiber laser with vanadium carbide deposited on tapered fiber

Vanadium carbide (V2C), a member of the MXene family, promises numerous possibilities in ultrafast laser technology with substantial applications in various optical industries. In this work, MXene V2C was deposited onto a tapered fiber using the drop-casting technique and incorporated into a thulium/holmium doped fiber laser cavity for generating mode-locked outputs in the 2.0 µm region. The fabricated SA exhibited nonlinear optical properties such as saturation intensity and modulation depth of 2.07 MW/cm2 and 7.57%, respectively. The findings of the mode-locked characteristics showed a central wavelength of 1937 nm with a signal-to-noise ratio (SNR) of 73 dB. Correspondingly, the laser-generated mode-locked pulses with output power, pulse energy, and peak power of 2.71 mW, 235.2 pJ, and 0.14 kW, respectively. The results suggest that the mode-locked laser obtained based on the MXene V2C could be applied to the field of photonics.

Q-switched EDF LASER Cavity using ITO as Saturable Absorber

In this work, we have experimentally reported Q-switched pulse generation by indium tin oxide as a saturable absorber. First the glass slide was placed in electron beam deposition chamber and indium tin oxide layer was coated over the glass slide. Then the indium tin oxide was exfoliated from the glass slide, over the fiber ferrules in erbium doped fiber laser cavity. The Q-switched laser operated at center wavelength of 1562.6 nm. The repetition rate and pulse width were obtained to be 48.31-64.52 kHz and 5.65-4.23 µs, respectively.

Passively mode-locked Er3+ and Tm3+-doped fiber lasers by using a common gold nanorods/D-shaped fiber as saturable absorber

We demonstrate passively mode-locked erbium/thulium doped fiber lasers (TDFLs) operating at 1560/1950 nm by using a common gold nanorods (GNRs)/D-shaped fiber as saturable absorber (SA). The SA is prepared by the composite of GNRs with an average aspect ratio of 5.3 and D-shaped fiber, which has broadband absorption from 1000 nm to 3000 nm. By inserting the same SA into an erbium or thulium doped fiber laser cavity, stable passively mode-locked laser at 1560 or 1950 nm is achieved, respectively. A 1560 nm laser with a pulse width of 590 fs and a repetition frequency of 25.72 MHz is obtained for the erbium doped fiber laser (EDFL), and a 1950 nm laser with a pulse width of 373 fs and a repetition rate of 27.66 MHz is also obtained for the TDFL. Our results show that the GNRs/D-shaped fiber SA could be used for constructing broadband femtosecond fiber lasers.

Q-switched lasing at the 2 µm wavelength induced by Cu18S nanocrystals

In this paper, we first investigated the nonlinear optical properties of Cu1.8S nanocrystals (NCs) by using Z-scan and balanced twin detector measurement technologies, and then demonstrated a passively Q-switched laser at the 2 µm wavelength. The Cu1.8S NCs were synthesized by a solventless thermolysis method and then mixed with sodium carboxymethylcellulose to form the Cu1.8S NCs film. The film exhibited broadband surface plasmon resonance (SPR) absorption from 800 nm to 2000 nm. By incorporating the Cu1.8S NCs film into a thulium doped fiber laser cavity pumped by a 1570 nm fiber laser, stable passive Q-switching at ∼1975.16 nm was obtained for a threshold pump power of ∼931 mW, and ∼3.4 µs pulse duration with a pulse repetition rate of ∼35.14 kHz was also obtained for a pump power of ∼996 mW. Our results showed that Cu1.8S NCs is a promising saturable absorber (SA) for pulse laser generation at the 2 µm wavelength.

Tungsten disulfide-chitosan film as optical pulse and amplitude modulator in C-band region

A tungsten disulfide (WS2)-Chitosan film based optical modulator for operation in the C-band region is demonstrated. The integration of the WS2-Chitosan film into an erbium doped fiber laser cavity reveals high optical pulse and amplitude modulation efficiency due to the substantial nonlinear absorption properties of the WS2-Chitosan film. The strong thermo-optic effect exhibited by the WS2-Chitosan film enables optical amplitude modulation, with modulation efficiencies of 0.10 dB mW−1 over a pump power ranging from 0.01 mW to 130.10 mW. The proposed WS2-Chitosan based optical modulator has significant potential for integration and application into a multitude of optoelectronic systems.

Large diameter coreless fiber as a saturable absorber for erbium doped fiber laser cavity based on multimode interference

• Easily handling C-band passively Q-switched erbium doped fiber laser nm has been demonstrated. • Easily spliced large core diameter coreless fiber is served as a saturable absorber for Q-switching ignition. • High pulse repetition rate of 73.3–92 KHz without any intra-cavity tuning element has been obtained. • Stable output pulses of SNR of 50 dB is generated. We demonstrated a Q-switched erbium-doped fiber laser (EDFL) based on large diameter coreless fiber without intra-cavity tuning element for the first time. A single mode fiber –coreless fiber –single mode fiber (SNCFS) structure was employed as a passive Q-switcher relies on Kerr nonlinearity associated with multi-mode interference (MMI) effect. By splicing 10 cm of 125 µm in diameter coreless fiber (NCF) between two single mode fibers (SMFs), C-band Q-switched EDFL with 3-dB bandwidth of 0.138 nm was successfully obtained, making it a simple, compact and easily handling modulation device. A stable Q-switched pulses were achieved with a pump threshold of 188 mW. Pulse repetition rate ranges from 73.3 to 92.0 kHz, minimum pulse width of 3.5 µs and maximum energy of 50.9 nJ were recorded.

Photodeposition of SWCNTs onto the optical fiber end to assemble a Q-switched Er3+-doped fiber laser

An experimental study on optical pulses generation using single-wall carbon nanotubes as a saturable absorbers in an Er3+-doped fiber laser is reported. The saturable absorber was made by the photodeposition technique to place single-wall carbon nanotubes onto an optical fiber end. This technique consists of light laser provided by an Er3+-doped fiber amplifier and single-wall carbon nanotubes suspended in an aqueous solution. Using a fiber splice tube, the optical fiber with the single-wall carbon nanotubes is placed in the Er3+-doped fiber laser cavity. The nonlinear absorption of the saturable absorber was characterized by P-scan technique using a high gain pulsed Er3+-doped fiber amplifier. The results demonstrated that is possible to obtain optical pulses generation by using the single-wall carbon nanotubes as saturable absorber. The pulses duration are from 8.5 to 18μs with a repetition rate around of 16–19.5kHz. The nonlinear absorption of the single-wall carbon nanotubes photodeposited onto an optical fiber end is approximately −5.25×10−6m/W.

Orange-light passively Q-switched Pr^3+-doped all-fiber lasers with transition-metal dichalcogenide saturable absorbers

We experimentally demonstrated compact orange-light passively Q-switched praseodymium (Pr3+)-doped all-fiber lasers utilizing two-dimensional (2D) transition-metal dichalcogenides (TMDs, WS2 and MoS2) as saturable absorbers (SAs). The filmy TMDs SAs are fabricated by evaporating the composite of TMDs nanosheets and polyvinyl alcohol (PVA), and then inserted into an orange-light Pr3+-doped fiber laser cavity, which is designed by coating dielectric mirrors on fiber ends. Stable passively Q-switched orange lasers at 604 nm are successfully achieved. The passive Q-switching generated the short pulse duration of 435 ns and 602 ns, as well as the tunable repetition rate in the range of 67.3 ~132.2 kHz and 50.8 ~118.4 kHz, respectively. This is, to the best of our knowledge, the shortest-wavelength operation of 2D-material-based pulsed fiber lasers.

635-nm Visible Pr3+-Doped ZBLAN Fiber Lasers Q-Switched by Topological Insulators SAs

Passive Q-switching of praseodymium (Pr3+)-doped fiber lasers at 635 nm with topological insulators (TIs) saturable absorbers (SAs) was experimentally demonstrated for the first time. TIs (Bi2Se3, Bi2Te3) nanosheets were embedded in polyvinyl alcohol for film-forming and incorporated into a visible Pr3+-doped fiber laser cavity for Q-switching operation, respectively. The Bi2Se3-based Q-switched fiber laser has a wide range pulse-repetition-rate from 191.6 to 454.5 kHz, and the Bi2Te3 one can be continuously tuned from 164.5 to 403.2 kHz. Both the Q-switching lasers have narrow pulse duration of nanosecond (ns)-level. Our results reveal that the TIs-based SAs are available for pulsed operation in the visible spectral range.

Gold nanoparticles as a saturable absorber for visible 635 nm Q-switched pulse generation

Gold nanoparticle (GNP) possesses saturable absorption bands in the visible region induced by surface plasmon resonance (SPR). We firstly applied the GNP as a visible saturable absorber (SA) for the red Q-switched pulse generation. The GNPs were embedded in polyvinyl alcohol (PVA) for film-forming and inserted into a praseodymium (Pr(3+))-doped fiber laser cavity to achieve 635 nm passive Q-switching. The visible 635 nm Q-switched fiber laser has a wide range of pulse-repetition-rate from 285.7 to 546.4 kHz, and a narrow pulse width of 235 ns as well as the maximum output power of 11.1 mW. The results indicate that the GNPs-based SA is available for pulsed operation in the visible spectral range.

Passively mode-locked fiber lasers at 1039 and 1560 nm based on a common gold nanorod saturable absorber

We demonstrated passively mode-locked ytterbium and erbium doped fiber lasers operating at 1039 and 1560 nm by using a common gold nanorods (GNRs) saturable absorber (SA). The GNRs with designed aspect ratios were mixed with sodium carboxymethylcelluose to form the GNRs SA film. The film had broadband longitudinal SPR (surface plasmon resonance) absorption from 800 to 1800 nm. By inserting the same film into a ytterbium or erbium doped fiber laser cavity pumped by a 980 nm laser diode, stable passively mode-locked laser operation at 1039 or 1560 nm was achieved for a threshold pump power of ~100 or ~70 mW, respectively. The pulse width, the output power, and the repetition rate of the 1039 nm mode-locked laser were 460 ps, 1.47 mW, and 43.5 MHz for a pump power of ~110 mW, respectively. The corresponding output parameters of the 1560 nm mode-locked laser were 2.91 ps, 2 mW, and 35.6 MHz for a pump power of ~74 mW, respectively. Our results showed that one GNRs SA could be used for constructing broadband mode-locked lasers.

Q-switching of Yb3+-doped fiber laser using a novel micro-optical waveguide on microactuating platform light modulator

We report a novel micro-optical waveguide (MOW) on microactuating platform (MAP) light modulator for Q-switched all-fiber laser applications. The light modulator employs a fused biconical taper (FBT) coupler, which acts as MOW, mounted on an electromechanical system, MAP, where an axial stress over the waist of FBT coupler is precisely controlled to result in modulation of output power. The modulator was implemented in a clad pumped Yb3+-doped fiber laser cavity as a Qswitching element. Q-switching was successfully achieved at the repetition rate of 18.6kHz and average pulse energy of 1.4microJ. The proposed structure can be readily applied in power scaling up of all-fiber Q-switching laser systems.