Ytterbium-doped Fiber Laser Cavity Research Articles

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 Ytterbium-doped fiber laser using zinc phthalocyanine thin film as saturable absorber

This paper presents a ZnPc: PVA film as saturable absorber (SA) for Q-switched pulse generation at 1-micron region. The SA film was obtained by embedding the ZnPc into polyvinyl alcohol (PVA). It was inserted into an Ytterbium-doped fiber laser (YDFL) cavity to act as a Q-switcher. The Q-switching operation was realized at the center of wavelength of 1036 nm with the minimum pulse width of 2.2 μs. The highest repetition rate and the maximum pulse energy were obtained at 63 kHz and 91 nJ, respectively. A signal to noise ratio (SNR) as high as 49 dB was observed, which indicates a stable operation of Q-switching in the YDFL cavity. This is the first demonstration of the use of ZnPc as Q-switcher in 1-micron wavelength region. A stable and high energy Q-switched pulse was realized with the proposed SA, which was obtained with a low-cost fabrication process.

Mechanical exfoliation of indium tin oxide as saturable absorber for Q-switched Ytterbium-doped and Erbium-doped fiber lasers

This work reports mechanically exfoliated indium tin oxide (ITO) as saturable absorber (SA) for Q-switched operation in fiber lasers. The ITO is mechanically exfoliated from 99.99% pure In2O3/SnO2. As ITO has a broad operational wavelength from visible to infrared, indium tin oxide saturable absorber (ITO-SA) is incorporated into ytterbium-doped fiber laser (YDFL) and erbium-doped fiber laser (EDFL) cavity for Q-switched operation. The Q-switched spectrum was observed to be centered at 1038.25 nm for ytterbium-doped fiber and 1557.8 nm for erbium doped fiber. The ITO-SA has a linear absorption of 2.25 dB and 2.5 dB at 1μm and 1.5μm respectively. A narrow pulse width was observed in the EDFL operating at 0.95 μs. For the first time, ITO-SA is incorporated to YDFL cavity.

Nonlinear photoresponse of metallic graphene-like VSe2 ultrathin nanosheets for pulse laser generation

Vanadium diselenide (VSe$_2$), a typical metallic behaviour material among transition metal dichalcogenides (TMDCs) family, exhibits excellent photoelectric characteristics with a zero band gap, missing applicaiotn in pulse generation. In this work, a high-quality VSe$_2$ saturable absorber (SA) was synthesized through a liquid-phase exfoliation method. The saturable absorption of obtained VSe$_2$-SA wascharacterized systematically. The measured modulation depth was 9.9%, and the saturated intensity was 533.8 $\mu$J/cm$^2$. By incorporating this optical modulator into a ytterbium-doped fiber laser cavity, a stable passively Q-switched laser could be achieved. The pulse had the central wavelength of 1064.03 nm. As the pump power was increased, the repetition rate increased from 24.3 kHz to 35.6 kHz, and the pulse duration decreased from 7.21 $\mu$s to 5.27 $\mu$s. The output power had the maximum value of 28.55 mW.These results indicated that VSe$_2$ is an effective candidate to generate pulse laser due to its excellent nonlinear optical properties and universal photoelectric response, which may advance the applications of VSe$_2$-based nonlinear optics and photoelectric devices.

Synthesis of carbon nanodots in zeolite SAPO-46 channels for Q-switched fiber laser generation

Carbon nanodots (C-dots) have gained much attention due to their unique optical and physicochemical properties. Herein, C-dots with uniform size have been fabricated via an in situ pyrolysis of dipropylamine (DPA) organic amines confined in the channels of SAPO-46 (AFS). The as-obtained C-dots@AFS composite material shows nonlinear optical property, which can be used as saturable absorber (SA) to generate Q-switched ytterbium-doped fiber laser (YDFL). By inserting the C-dots@AFS SA into an YDFL cavity pumped by a 980 nm laser diode, stable passively Q-switched fiber laser can be obtained for a threshold pump power of 220 mW, and 4.5 μs pulses with a repetition rate of 33.51 kHz can be obtained for a pump power of 380 mW. To the best of our knowledge, this is the first demonstration of a C-dots@AFS-based Q-switched fiber laser.

Cobalt oxide nanocubes thin film as saturable absorber for generating Q-switched fiber lasers at 1 and 1.5 µm in ring cavity configuration

Abstract We experimentally demonstrate Q-switched fiber lasers based on Ytterbium-doped fiber laser (YDFL) and Erbium-doped fiber laser (EDFL) cavity using cobalt oxide (Co3O4) nanocubes film as a saturable absorber (SA) to operate at 1043.64 nm and 1560.4 nm respectively. This material is embedded into polyethylene oxide (PEO) film to obtain a high nonlinear optical response that can be used for SA application. The Co3O4 nanocubes film was fabricated by a simple processing technique and it has a modulation depth of 4% and saturation intensity of 56 MW/cm2. By incorporating the Co3O4 nanocubes SA into the YDFL cavity, a stable Q-switched pulse train was generated with repetition rate increasing from 60.3 to 86.66 KHz, by increasing the pump power from 144.4 to 165.4 mW. At the pump power of 147.9 mW the pulse width and pulse energy are 4 µs and 154 nJ respectively. The EDFL generates a stable Q-switched pulses with repetition rate of 119.7 KHz, pulse width of 2.4 µs and pulse energy of 6 nJ at maximum pump power of 141 mW. This results propose that cobalt oxide could be a promising broadband SA for all fiber lasers wavelengths at 1 and 1.5 µm.

Mode-locked ytterbium-doped fiber laser using mechanically exfoliated black phosphorus as saturable absorber

We experimentally demonstrated a passive, stable mode-locked ytterbium-doped fiber laser (YDFL) based on black phosphorus (BP) as saturable absorber (SA). The BP-SA was prepared by mechanically exfoliation of the crystal and transferred the acquired thin layer onto the end surface of a standard FC/PC fiber connector. By incorporating the BP-SA into the YDFL cavity, a stable mode-locked operation was obtained at 1033.76nm wavelength with a repetition rate of 10MHz. The maximum pulse energy of 2.7nJ and peak power of 0.83kW were obtained at the maximum pump power of 200mW. The experimental results indicate that the BP SA can be used successfully to generate stable mode-locking pulse at 1μm region.

Passively mode-locked ytterbium-doped fiber laser operation with few layer MoS2 PVA saturable absorber

A passive mode-locked Ytterbium-doped fiber laser (YDFL) is experimentally demonstrated using a multi-layered molybdenum disufide (MoS2) as a Saturable Absorber (SA). The MoS2 film was obtained based on a liquid phase exfoliation of MoS2 crystal. A small slice of MoS2 film was sandwiched in between two optical ferrules via a fiber adapter and linked into an YDFL cavity to generate a stable mode-locked operation at a wavelength of 1073.86nm with repetition rate of 18.8MHz. At pump power of 202.9mW, the maximum pulse energy of 0.1nJ was achieved with an output power of 1.84mW. The MoS2 film was fabricated through a simple process and it has a modulation depth of 9.7% and saturating intensity of 40 MW/cm2.

Q-switched ytterbium-doped fiber laser with topological insulator-based saturable absorber

A stable passive Q-switched ytterbium-doped fiber laser (YDFL) operating at 1057.4 and 1044.5 nm is demonstrated using two types of topological insulator-based saturable absorbers (SAs): bismuth (III) selenide (Bi2Se3) and bismuth (III) telluride (Bi2Te3). These materials are embedded in polyvinyl alcohol film and incorporated in the YDFL cavity. Using Bi2Se3 SA, the YDFL obtains a stable train of pulses with a repetition rate that is tunable from 48.83 to 102 kHz. Meanwhile, the corresponding pulse width decreases from 8.9 to 3.48 μs as the pump power increases from 67.6 to 88.3 mW. For the Bi2Te3-based Q-switched YDFL, the repetition rate grows from 43.25 to 93.63 kHz and the pulse width shrinks from 5.65 to 2.01 μs as the 980-nm pump power rises from 72.8 to 98.4 mW. The maximum pulse energy is obtained with the Bi2Te3 SA at 29.95 nJ.

Passively Q-switched Ytterbium doped fiber laser with mechanically exfoliated MoS2 saturable absorber

A passively Q-switched Ytterbium-doped fiber laser (YDFL) based on MoS2 saturable absorber (SA) is demonstrated. A few layers of MoS2 are mechanically exfoliated from a natural MoS2 crystal using a scotch tape and the resulting SA is sandwiched between two fiber ferrules to form a fiber compatible Q-switcher. The saturation intensity, non-saturable intensity, and modulation depth of the MoS2 SA are 23.5 MW/cm2, 23.0, and 11.3%, respectively. By introducing the MoS2 SA into the YDFL cavity, a stable pulse laser is generated at 1070.2 nm wavelength with a threshold pump power of 49.57 mW. The repetition rate of the Q-switched pulses ranges from 3.817 to 25.25 kHz, as the 980 nm pump power increases from 49.57 to 87.2 mW. The highest pulse energy is 295.45 nJ at a pump power of 87.2 mW.

Generation of Mode-Locked Ytterbium Doped Fiber Ring Laser Using Few-Layer Black Phosphorus as a Saturable Absorber

We demonstrate the generation of mode-locked pulses from a double-clad ytterbium-doped fiber laser (YDFL) employing a saturable absorber (SA) made of a few layers of black phosphorus (BP). The BP SA was prepared by mechanically exfoliating BP crystal and spreading the acquired BP flakes on a piece of scotch tape. The tape was then sandwiched between two ferrules and incorporated in a YDFL cavity to achieve a stable mode-locked operation at 1085.58 nm with a repetition rate of 13.5 MHz. A maximum pulse energy of 5.93 nJ was obtained at pump power of 1322 mW with the output power of 80 mW. Our study may well be the first demonstration of the BP-based mode-locked fiber laser that should shed some new insights into two-dimensional layer materials related photonics.

Q-Switched Ytterbium-Doped Fiber Laser Using Black Phosphorus as Saturable Absorber

We demonstrate a Q-switched ytterbium-doped fiber laser (YDFL) using a newly developed multi-layer black phosphorous (BP) saturable absorber (SA). The BP SA is prepared by mechanically exfoliating a BP crystal and sticking the acquired BP flakes onto a scotch tape. A small piece of the tape is then placed between two ferrules and incorporated in a YDFL cavity to achieve a stable Q-switched operation in a 1.0μm region. The laser has a pump threshold of 55.1 mW, a pulse repetition rate that is tunable from 8.2 to 32.9 kHz, and the narrowest pulse width of 10.8 μs. The highest pulse energy of 328 nJ is achieved at the pump power of 97.6mW. Our results show that multi-layer BP is a promising SA for Q-switching laser operation.

Generation of Mode-locked Ytterbium doped fiber ring laser using few-layer black phosphorus as a saturable absorber

We demonstrate the generation of mode-locked pulses from a double-clad ytterbium-doped fiber laser (YDFL) employing a saturable absorber (SA) made of a few layers of black phosphorus (BP). The BP SA was prepared by mechanically exfoliating BP crystal and spreading the acquired BP flakes on a piece of scotch tape. The tape was then sandwiched between two ferrules and incorporated in a YDFL cavity to achieve a stable mode-locked operation at 1085.58 nm with a repetition rate of 13.5 MHz. A maximum pulse energy of 5.93 nJ was obtained at pump power of 1322 mW with the output power of 80 mW. Our study may well be the first demonstration of the BP-based mode-locked fiber laser that should shed some new insights into two-dimensional layer materials related photonics.

PMMA-doped CdSe quantum dots as saturable absorber in a Q-switched all-fiber laser

We demonstrate the generation of Q-switched pulses from an ytterbium-doped fiber laser (YDFL) using quantum dot (QD) CdSe as a passive saturable absorber (SA). The CdSe QD is fabricated by the synthesis of CdO, Se, and manganese acetate and paraffin oil and oleic acid as the solvent and surfactant, respectively. The CdSe QD is then doped into poly-methyl-methacrylate (PMMA) via an emulsion polymerization process. A PMMA-hosted CdSe QD thin flake with a homogeneous end surface is then formed and placed between two ferrules and assembled in a YDFL cavity to achieve the Q-switching operation with a repetition rate of 24.45 to 40.50 kHz while varying the pump power from 975 to 1196 mW. The pulse width changes from 6.78 to 3.65 μs with a maximum calculated pulse energy at 0.77 μJ at a pump power of 1101 mW. This work may be the first demonstration of CdSe QD-based Q-switching in an all-fiber configuration that should give proportional insight into semiconductor QD materials in photonics applications.

Gold nanorod saturable absorber for passive mode-locking at 1 μm wavelength

Gold nanorods (GNRs) were used as a saturable absorber (SA) for passive mode-locking at 1 μm wavelength. The GNR-SA film was fabricated by mixing GNRs with sodium carboxymethylcellulose. The longitudinal surface plasmon resonance absorption of GNRs was used to induce mode-locking. By using the GNR-SA film, stable passive mode-locking at 1039 nm was experimentally demonstrated in an ytterbium-doped fiber laser cavity pumped by a 980 nm laser diode. The laser produced ∼440 ps pulses with a repetition rate of 36.6 MHz and an average output power of ∼1.25 mW for a pump power of ∼82 mW.

Passively harmonic mode locking in ytterbium-doped fiber laser with graphene oxide saturable absorber

We have demonstrated the dissipative solitons generated in an ytterbium-doped fiber laser cavity using graphene oxide as the saturable absorber. The lasing light, centered at 1077.2 nm, has a 3 dB spectral bandwidth of similar to 1.12 nm. Under different launched pump powers and appropriate polarization orientations, harmonic mode-locked of second-and third-order pulse trains have been achieved; the corresponding 3-dB bandwidth and pulse duration have been detected. (C) The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

106μm Q-switched ytterbium-doped fiber laser using few-layer topological insulator Bi_2Se_3 as a saturable absorber

Passive Q-switching of an ytterbium-doped fiber (YDF) laser with few-layer topological insulator (TI) is, to the best of our knowledge, experimentally demonstrated for the first time. The few-layer TI: Bi2Se3 (2-4 layer thickness) is fabricated by the liquid-phase exfoliation method, and has a low saturable optical intensity of 53 MW/cm2 measured by the Z-scan technique. The optical deposition technique is used to induce the few-layer TI in the solution onto a fiber ferrule for successfully constructing the fiber-integrated TI-based saturable absorber (SA). By inserting this SA into the YDF laser cavity, stable Q-switching operation at 1.06 {\mu}m is achieved. The Q-switched pulses have the shortest pulse duration of 1.95 {\mu}s, the maximum pulse energy of 17.9 nJ and a tunable pulse-repetition-rate from 8.3 to 29.1 kHz. Our results indicate that the TI as a SA is also available at 1 {\mu}m waveband, revealing its potential as another wavelength-independent SA (like graphene).