Black Phosphorus Saturable Absorber Research Articles

Large Energy Q-Switched Fiber Laser With Black Phosphorus Saturable Absorber Fabricated by Sol−Gel Technique

Large Energy Q-Switched Fiber Laser With Black Phosphorus Saturable Absorber Fabricated by Sol−Gel Technique

Passively Q-Switched Operation of Tm∶YAP Laser with Black Phosphorus Saturable Absorber

Passively Q-Switched Operation of Tm∶YAP Laser with Black Phosphorus Saturable Absorber

Sub-150 fs dispersion-managed soliton generation from an all-fiber Tm-doped laser with BP-SA.

We demonstrate an all-fiber, thulium-doped, mode-locked laser using a black phosphorus (BP) saturable absorber (SA). The BP-SA, exhibiting strong nonlinear response, is fabricated by inkjet printing. The oscillator generates self-starting 139 fs dispersion-managed soliton pulses centered at 1859nm with 55.6 nm spectral bandwidth. This is the shortest pulse duration and widest spectral bandwidth achieved directly from an all-fiber thulium-doped fiber laser mode-locked with a nanomaterial saturable absorber to date. Our findings demonstrate the applicability of BP for femtosecond pulse generation at 2 µm spectral region.

Dark pulse mode-locked fibre laser with zirconia-based erbium-doped fibre (Zr-EDF) and Black phosphorus saturable absorber

A dark pulse multi-wavelength mode-locked fibre laser was demonstrated via the enhanced zirconia-yttria-aluminium co-doped silica fibre (Zr-EDF) as a gain medium with the utilisation of black phosphorus as saturable absorber (BPSA). A self-started dark pulse was accomplished by increasing the pump power and carefully rotating a polarisation controller (PC). Five lasing lines of multi-wavelength were generated with small constant channel spacing of 0.6 nm. The measured fundamental repetition rate was 1 MHz with a pulse duration of 3.46 ps. At output power 9.89 mW, the calculated pulse energy was 9.89 nJ, whereas the optical signal to noise ratio (OSNR) was as high as 74.8 dB, which confirmed the stability of the dark pulse train.

Recent progress of pulsed fiber lasers based on transition-metal dichalcogenides and black phosphorus saturable absorbers

Abstract Transition-metal dichalcogenides (TMDCs) and black phosphorus (BP) are typical 2D materials with layer-dependent bandgaps, which are emerging as promising saturable absorption materials for pulsed fiber lasers. In this review, we discuss the nonlinear saturable absorption properties of TMDCs and BP, and summarize the recent progress of saturable absorbers from fabrication methods to incorporation strategies. The performances of saturable absorbers and the properties of Q-switched/mode-locked fiber lasers at different wavelengths are summarized and compared to give a comprehensive insight to optical modulators based on TMDCs/BP, and to promote their practical applications in nonlinear optics.

Environmentally stable black phosphorus saturable absorber for ultrafast laser

Abstract Black phosphorus (BP) attracts huge interest in photonic and optoelectronic applications ranging from passive switch for ultrafast lasers to photodetectors. However, the instability of chemically unfunctionalized BP in ambient environment due to oxygen and moisture remains a critical barrier to its potential applications. Here, the parylene-C layer was used to protect inkjet-printed BP-saturable absorbers (BP-SA), and the efficacy of this passivation layer was demonstrated on the stable and continuous operation of inkjet-printed BP-SA in harsh environmental conditions. BP-SA was integrated in an erbium-doped ring laser cavity and immersed in water at ~60°C during operation for investigation. Mode-locked pulses at ~1567.3 nm with ~538 fs pulse width remained stable for >200 h. The standard deviation of spectral width, central wavelength, and pulse width were 0.0248 nm, 0.0387 nm, and 2.3 fs, respectively, in this period, underscoring the extreme stability of BP-SA against high temperature and humidity. This approach could enable the exploitation of BP-based devices for photonic applications when operating under adverse environmental conditions.

Two-dimensional material as a saturable absorber for mid-infrared ultrafast fiber laser

The two-dimensional (2D) nanomaterial saturable absorber represented by graphene is widely used in ultrafast fiber lasers due to its unique nonlinear optical properties. In this paper, we summarize the research and development of 2D nanomaterials as saturable absorbers in mid-infrared ultrafast mode-locked fiber lasers in recent years, and introduce the atomic structure and nonlinear optical characteristics of 2D nanomaterials, and saturable absorber device integration methods. The laser performance parameters such as center wavelength, repetition frequency and average output power of the laser are discussed, and the femtosecond fiber laser based on black phosphorus saturable absorber in the middle infrared band is highlighted. Finally, the developments and challenges of 2D materials in mid-infrared pulsed fiber laser are also addressed.

Bright/dark switchable mode-locked fiber laser based on black phosphorus

Stable bright/dark switchable mode-locked nanosecond pulse fiber laser incorporating black phosphorus (BP) was demonstrated in the Yb-doped fiber ring cavity for the first time, to the best of our knowledge. The high-quality BP saturable absorber (SA) was fabricated by the modified electrochemical delamination exfoliation process. The states between bright and dark pulse could be switched by simply adjusting the intra-cavity polarization states, and close agreement with the cubic Ginzburg-Landau equation (CGLE) models is present.

Self-Q-switching and passively Q-switched mode-locking of dual-wavelength Nd:YSAG laser

In this paper, self-Q-switched (SQS) and passively Q-switched mode-locked (QML) dual-wavelength Nd:YSAG lasers are reported, that works at 1058.97 and 1061.49 nm, simultaneously. Till now, the performance on SQS, and passively QML operation by using black phosphorus (BP) in Nd:YSAG crystal lasers have not been reported as per the author’s knowledge. The Nd:YSAG laser SQS operation was realized by designing a simple plano-plano resonator cavity. The maximum output power of 0.471 W at absorbed pump power 2.64 W and the pulse duration was 885 ns. The Nd:YSAG laser QML operation was realized by designing a Z-type resonator cavity. The duration of mode-locked pulse inside the Q-switched envelop was estimated to be 235 ps with 96.5 MHz repetition rate at the absorbed pump power of 4.08 W in QML with black phosphorus saturable absorber (BP-SA).

Oxidation-Resistant Black Phosphorus Enable Highly Ambient-Stable Ultrafast Pulse Generation at a 2 μm Tm/Ho-Doped Fiber Laser.

Black phosphorus (BP) ranks among the most promising saturable absorber materials for ultrafast pulse generations at 2 μm. However, the easy-to-degrade characteristic of BP seriously limits the long-term operation of ultrafast fiber lasers and hence becomes a bottleneck for its relevant practical applications. In this paper, a modified electrochemical delamination exfoliation process was explored to produce high-performance, large-size, and oxidation-resistant BP nanosheets, where BP nanosheets in high yield with evenly coated tetra-n-butyl-ammonium organics by precisely controlling the intercalation chemistry can be obtained. A mode-locked Tm/Ho co-doped fiber laser with high temporal stability and long-term operation capability was demonstrated based on the innovatively fabricated BP saturable absorber. The self-starting mode-locking operation featuring a high signal-to-noise ratio of 58 dB and long-term stability has been verified for at least 3 weeks, which indicates the successful passivation of the employed synthesis method. These results fully indicated that passivated BP is an efficient candidate in a 2 μm range ultrafast photonic field, which will promote the ultrafast optical application of BP and also other infrared photonic and photoelectronic devices.

Passively Q-switched diode-pumped Tm, Ho:LuVO4 laser with a black phosphorus saturable absorber**Project supported by the National Natural Science Foundation of China (Grant Nos. 61775053, 51572053, 51777046, and 61705140).

We presented a passively Q-switched (PQS) diode-pumped c-cut Tm, Ho:LuVO4 laser with a black phosphorus saturable absorber for the first time. Under PQS mode, an average output power of 0.86 W and a peak power of 2.32 W were acquired from the Tm, Ho:LuVO4 laser with the pump power of 14.55 W, corresponding to a pulse width of , a pulse repetition rate of 71.84 kHz, and a pulse energy of about .

Switchable and tunable multi-wavelength emissions in pulsed ytterbium fiber lasers with black phosphorus saturable absorbers and polarization-maintaining fiber Bragg gratings

In this paper, we present a systematic study of ytterbium-doped pulsed fiber lasers, both Q-switched and mode-locked, that emitted in switchable and tunable multi-wavelength states. The pulsed lasers were initiated by black phosphorus saturable absorbers (BP-SAs) prepared by an optically driven process. One relatively thicker BP-SA with a modulation depth of 16.8% and a saturable intensity of 13.09 MW/cm2 was used for Q switching, and one thinner BP-SA with a modulation depth of 6.7% and a saturable intensity of 7.82 MW/cm2 was used for mode locking. The switchable and tunable wavelength-emitting status was achieved by a Bragg grating written in polarization maintaining fibers (PM-FBG). The fabricated fiber Bragg grating had two reflection peaks. By adjusting an in-cavity polarization controller, the wavelength-emitting status of the pulsed lasers was flexibly switched in three discrete states: individual wavelength of 1063.8 and 1064.1 nm, respectively; and simultaneously emitting both wavelengths with tuning capability. Stable Q-switched and mode-locked laser pulses were observed with all three wavelength-emitting states. Furthermore, by applying stresses at the fast or slow axis of the utilized PM-FBG, the wavelength spacing could be tuned from 0.02 to 0.52 nm in the dual-wavelength emission state.

Black phosphorus-enabled harmonic mode locking of dark pulses in a Yb-doped fiber laser

The harmonic mode locking of dark pulses based on black phosphorus is proposed and observed in a Yb-doped fiber laser for the first time, to the best of our knowledge. The order of harmonic mode locking could be readily switched by adjusting the intra-cavity polarization states only. Up to an 11th order harmonic dark pulse was observed. A numerical investigation based on the extended nonlinear Schrödinger equation is employed to confirm the generation of dark pulses in the laser, which proves that harmonic dark pulses are an intrinsic feature of fiber lasers. A black phosphorus saturable absorber is fabricated by the modified mineralizer-assisted chemical vapor transport method. This work illustrates that black phosphorus is a promising material in laser optics. We anticipate that our work will stimulate the applications of black phosphorus in many other photonic systems.

Nanosecond level passively Q-switched Nd:YAG and Nd:YVO4 laser using black phosphorus as a saturable absorber

Black phosphorus (BP) saturable absorber (SA) solution is fabricated by liquid-phase exfoliation method. By using the BP-SA solution, a compact diode-pumped passively [Formula: see text]-switched Nd:YAG and [Formula: see text] laser has been demonstrated. 100 Hz and 1 kHz repetition rate pulse lasers are achieved, respectively. The minimum pulse duration is 3.56 ns. In the [Formula: see text]-switched [Formula: see text] laser with wideband absorbers, the lowest repetition rate and the shortest pulse duration are obtained for the first time to the best of our knowledge. The maximum single pulse energy is as much as 0.1 mJ. Our results show that BP-SA solution can be developed as an effective SA to achieve nanosecond pulse laser.

Q-switched Dy:ZBLAN fiber lasers beyond 3 μm: comparison of pulse generation using acousto-optic modulation and inkjet-printed black phosphorus

We report high-energy mid-infrared pulse generation by Q-switching of dysprosium-doped fiber lasers for the first time. Two different modulation techniques are demonstrated. Firstly, using active acousto-optic modulation, pulses are produced with up to 12 μJ energy and durations as short as 270 ns, with variable repetition rates from 100 Hz to 20 kHz and central wavelengths tunable from 2.97 to 3.23 μm. Experiments are supported by numerical modeling, identifying routes for improved pulse energies and to avoid multi-pulsing by careful choice of modulator parameters. Secondly, we demonstrate passive Q-switching by fabricating an inkjet-printed black phosphorus saturable absorber, simplifying the cavity and generating 1.0 μJ pulses with 740 ns duration. The performance and relative merits of each modulation approach are then critically discussed. These demonstrations highlight the potential of dysprosium as a versatile gain medium for high-performance pulsed sources beyond 3 μm.

Passively Q-switched cylindrical vector laser based on a black phosphorus saturable absorber

We demonstrate an all-fiber Q-switched cylindrical vector laser based on a black phosphorus saturable absorber and a transverse mode converter. The saturable absorber is prepared by incorporating the polyvinyl alcohol with anti-oxidized black phosphorus nanosheets exfoliated in aqueous poly(dimethyldiallyl ammonium chloride) solution. The mode converter is composed of a tapered two-mode fiber and a single-mode fiber, and it can excite switchable azimuthally and radially polarized beams by modulating the input polarization. By enhancing the pump power from 64.68 to 174.82 mW, the repetition rate of the Q-switched azimuthally/radially polarized laser enlarges from 16.72/19.25 to 30.71/37.82 kHz.

Wideband wavelength-tunable ultrafast fiber laser based on black phosphorus saturable absorber

We report a wideband wavelength-tunable ultrafast fiber laser mode-locked with a few-layer black phosphorus (BP) saturable absorber. The proposed laser not only delivers picosecond stable conventional solitons but also exhibits flexible wavelength tunability from 1529 to 1592 nm. It is experimentally demonstrated that the broadband saturable absorption property of BP and birefringence filtering effects in the cavity contribute significantly to the aforementioned merits. In addition, the round-trip model is established to numerically demonstrate the spectral evolution, and numerical results are in good agreement with experimental observations. The proposed laser system is compact and wavelength-tunable, which provides an efficient solution for applications where a widely tunable ultrafast fiber laser is required.

Black Phosphorus Saturable Absorber for Pulse Generation Using Q-switched Teachnique

This paper reported a passive Q-switched erbium doped fiber laser (EDFL) using two-dimensional (2D) material of black phosphorus saturable absorber (BP-SA). The maximum output power reached is 3.54 mW, which is generated by pump power of 42.327 mW. The results show that a stable pulse was generated with repetition rate starts at about 9.606 kHz and ends at about 44.72 kHz and very narrow pulse width between 40.01 µs and 9.84 µs and pulse energy 80 nJ. Clearly, the stability of the Q-switched pulse train was achieved because the BP-SA film was inserted in the laser ring cavity.

Passively Q-switched all-fiber lasers generating cylindrical vector beams with 2-dimensional material saturable absorbers

Abstract In this paper, we present systematic experimental demonstrations of Q-switched all-fiber lasers generating cylindrical vector beam (CVB) outputs with 2D-material-based saturable absorbers, including graphene and black phosphorus (BP). The graphene and BP saturable absorbers are both fabricated by an optically driven method. Both radially and azimuthally polarized CVB laser pulses are realized by adjusting a pair of polarization controllers combined with an offset splice spot and a few-mode fiber Bragg grating. Our experimental effort provides a concise, reliable, and complete all-fiber laser route towards pulsed CVB emissions based on 2D-material saturable absorbers.

102 fs pulse generation from a long-term stable, inkjet-printed black phosphorus-mode-locked fiber laser.

We demonstrate a long-term stable, all-fiber, erbium-doped femtosecond laser mode-locked by a black phosphorus saturable absorber. The saturable absorber, fabricated by scalable and highly controllable inkjet printing technology, exhibits strong nonlinear optical response and is stable for long-term operation against intense irradiation, overcoming a key drawback of this material. The oscillator delivers self-starting, 102 fs stable pulses centered at 1555 nm with 40 nm spectral bandwidth. This represents the shortest pulse duration achieved from black phosphorus in a fiber laser to date. Our results demonstrate the great potential for black phosphorus as an excellent candidate for long-term stable ultrashort pulse generation.