Q-switched Erbium-doped Fiber Laser Research Articles

Nanosecond passively Q-switched fiber laser in the 1.5 µm region using turmeric saturable absorber

We report a passively Q-switched Erbium-doped fiber laser (EDFL) at 1566.96 nm by applying a new type of organic material based on turmeric as the saturable absorber (SA). The material was prepared by the embedding turmeric powder into polyvinyl alcohol (PVA) film. The prepared thin film was inserted between two fiber ferrules and integrated into an EDFL cavity to generate Q-switched pulses at threshold pump power of 119 mW. The maximum Q-switched pulse average power and pulse energy were 13.6 mW and 150.96 nJ, respectively under the input pump power of 255 mW. The highest pulse repetition rate and shortest pulse duration was 90.09 kHz and 725 ns, respectively. The finding indicates that the turmeric material has performed well as SA in the 1.5 µm spectral region.

Few-layer TaSe2 as a saturable absorber for passively Q-switched erbium-doped fiber lasers

TaSe2 nanosheets are prepared by means of ultrasound-assisted liquid phase exfoliation (LPE) and the nonlinear saturable absorption properties are experimentally investigated. The TaSe2-polyvinyl alcohol (PVA) film is then manufactured and a TaSe2-based saturable absorber (SA) is fabricated for demonstrating a Q-switched erbium-doped fiber laser (EDFL) for the first time. Taking advantage of the saturable absorption properties of the TaSe2-based SA, the obtained shortest Q-switched pulse duration is 1.53 µs with a pulse energy of 65.5 nJ. The results indicate that TaSe2 is a competent candidate for use as SA in promoting stable and flexible ultrafast lasers. The work may pave the way to researches and applications for photonics in the mid-infrared band.

8-Hydroxyquinolino cadmium chloride hydrate for generating nanosecond and picosecond pulses in erbium-doped fiber laser cavity

In this paper, we experimentally proposed and demonstrated the application of thin-film saturable absorber (SA) based on 8-Hydroxyquinolino cadmium chloride hydrate (8-HQCdCl2H2O) material as both Q-switcher and mode-locker in the cavity of erbium-doped fiber laser (EDFL). The 8-HQCdCl2H2O was embedded in polyvinyl alcohol (PVA) to fabricate the thin-film, which has then employed in the Q-switched and mode-locked EDFL cavity for passively generating nanosecond and picosecond pulses, respectively. At the maximum pump power of 167 mW, the Q-switched laser-produced pulse train with a pulse width of 726 ns, a repetition rate of 150 kHz, and a signal-to-noise ratio (SNR) of 72 dB. We also demonstrated the generation of mode-locked picosecond pulses by adding 200 m long single-mode fiber (SMF) into the ring EDFL cavity. The mode-locked laser-generated pulses have a pulse width of 1.83 ps, a repetition rate of 1 MHz, and the SNR of 77 dB for the electrical spectrum.

Passively Q-Switched Erbium-Doped Fiber Laser Based on GeSe Saturable Absorber

GeSe nanosheets were prepared by ultrasonic-assisted liquid phase exfoliation (LPE), and the nonlinear saturated absorption performance was experimentally studied. The modulation depth and saturation intensity of the prepared GeSe saturable absorber (SA) were 15% and 1.44 MW/cm2, respectively. Using the saturated absorption characteristics of GeSe SA, a passively Q-switched erbium-doped fiber laser was systematically demonstrated. As the pump power increases, the pulse repetition frequency increases from 22.8 kHz to 77.59 kHz. The shortest pulse duration is 1.51 μs, and the corresponding pulse energy is 46.14 nJ. Experimental results show that GeSe nanosheets can be used as high-efficiency SA in fiber lasers. Our results will provide a useful reference for demonstrating pulsed fiber lasers based on GeSe equipment.

Two-dimensional hexagonal boron nitride as saturable absorber for a 1.5 µm passively Q-switched erbium-doped fiber laser.

We report on two-dimensional (2D) hexagonal boron nitride (hBN) as saturable absorber (SA) material in a passively Q-switched erbium-doped fiber laser (EDFL) operating at 1.5 µm. The 2D hBN film as an SA is fabricated and transferred onto the optical fiber tip by natural deposition technology. In the Q-switched operation, we obtain stable Q-switched laser operation with a maximum average 10% output power of 2.25 mW, corresponding to a repetition frequency of 55.5 kHz, shortest pulse width of 6.77 µs, and single pulse energy of 40.49 nJ. The achieved PQS at 1.5 µm EDFL with 2D hBN as an SA may have potential applications in many novel 2D materials and all-fiber lasers.

C-band tunable Q-switched fiber laser based on Alq3 as a saturable absorber

We propose a Q-switched erbium-doped fiber laser (EDFL) with a wide-tuning wavelength range by using Alq3 as a saturable absorber (SA). A tunable bandpass filter (TBF) was integrated into the cavity to produce a tunable wavelength. The wavelength was shifted continuously with ease from 1520 nm to 1563.3 nm covering almost all C-band region. The fiber laser showed a very stable performance in which the signal to noise ratio (SNR) of around 53 dB was recorded at different wavelengths. To the best of our knowledge, this work demonstrates for the first time that Alq3 has the potential to be used as an effective SA for broadband tunable Q-switched fiber lasers.

Plasma sputtered platinum saturable absorber with variable sputtering time for Q-switched erbium-doped fiber laser

In this work, we experimentally demonstrate a study on the influence of the parameters of plasma sputtered platinum (Pt) saturable absorbers (SA) on the performance of Q-switched erbium-doped fiber laser (EDFL). We fabricated a set of five Pt saturable absorbers with different sputtering time ranging from 50 to 400 s. The Pt SAs were fabricated via plasma sputter deposition method and deposited directly on the fiber connector end face. Each SA was characterized in terms of morphology and surface roughness, as well as the linear and nonlinear optical parameters. In our setup, the best performance in terms of bandwidth and pulse duration (7.84 nm and 5.2 µs) was achieved with 50 s of sputtering time. This is the first reported study on controlling the parameters of SA by varying the sputtering time of Pt.

Generation of Q-switched and mode-locked pulses using neodymium oxide as saturable absorber

Generations of Q-switched and mode-locked pulses were successfully demonstrated in an erbium-doped fiber laser (EDFL) cavity using Neodymium oxide (Nd2O3) as saturable absorber (SA). Nd2O3 nano-powder was mixed with aqueous solution of polyvinyl alcohol (PVA) to form a thin film after a drying process. The thin film was used to form a SA device. A stable Q-switched EDFL pulses operating at a wavelength of 1558.5 nm were successfully obtained by incorporating the device into the laser cavity. The pulse’s repetition rate rose from 89.45 to 104 kHz while the pulse width shrunk from 2.56 to 2.19 µs as the pump power was varied from the threshold of 91.17 to 142.08 mW. The output power steadily increased from 9.57 to 13.94 mW with a slope efficiency of 8.42% as the pump power was raised in the same range. Meanwhile, a stable mode-locked laser operating in soliton regime was also realized as the additional 100 m SMF was incorporated into the laser cavity. The laser operated at a central wavelength of 1559 nm with visible Kelly sidebands. The soliton pulses operated at a fixed repetition rate of 1.809 MHz with a pulse width of 4.62 ps as the pump power was varied within 25.03 to 75.92 mW. The peak power of the mode-locked laser increased from 0.37 kW to 1.26 kW as the pump power was varied within the pump power range. The finding reveals the outstanding optical nonlinearity of Nd2O3, which can open new potential in pulsed laser development for various applications including, optical communication, material processing, biomedical diagnostic etc.

Q-switched tunable fiber laser with aluminum oxide saturable absorber and Sagnac loop mirror

A Q-switched erbium-doped fiber laser with tunable output wavelength was demonstrated by utilizing aluminum oxide saturable absorber in conjunction with Sagnac loop mirror (SLM) filter. As the SLM temperature was increased from 30 to 70 °C, the laser operation can be tuned from 1568 to 1556 nm. At 1568 nm operation, the laser pulse frequency can be raised from 13.66 to 26.25 kHz by increasing the pump power from the threshold of 53 to 87 mW. With the increase in temperature, it is found that the pump threshold for the Q-switching increased, while the laser operation shifted to a shorter wavelength.

Single/dual-wavelength switchable and tunable passively Q-switched erbium-doped fiber laser

We demonstrate a passively Q-switched erbium-doped fiber laser (EDFL) with a birefringent Sagnac loop mirror (SLM) that combines the gain spectrum enables the laser to operate in tunable and switchable single/dual-wavelength states. When the pump power is up to 300 mW, the stable Q-switched pulse with the repetition rate and pulse duration of 58.57 kHz and 17.07 μs is achieved by properly adjusting the polarization controller-1 (PC-1) in the cavity. Meanwhile, the tunable and switchable single wavelength and dual wavelength regime is achieved by modulating the PC-2 in SLM, whose tunable ranges of single and dual wavelength are 3.27 nm and 1.69 nm, respectively. The proposed laser may meet the great application demands in nonlinear optics at 1.5 μm band.

Q-switched erbium-doped fiber laser with silicon oxycarbide saturable absorber

We have experimentally demonstrated a Q-switched erbium doped fiber laser (EDFL) by using silicon oxycarbide (SiOC) as saturable absorber (SA). The SiOC was prepared by reactive RF magnetron sputtering before being mechanically exfoliated and inserted in cavity to generate Q-switched pulses operating at 1561.7 nm. Pulses as short as 2.1 μs were generated at the repetition rate of 96.7 kHz, having signal to noise ratio (SNR) of 70 dB. The Q-switched EDFL pulses remained stable between pump powers of 111.5−198 mW. At the pump power value of 198 mW, the Q-switched EDFL generated pulses with output power of 2.4 mW and high pulse energy of about 25 nJ. For the first time SiOC is introduced to be used as a SA in the EDFL cavity for Q-switched laser sources.

Q-switched and tunable wavelength fiber laser utilizing nickel oxide saturable absorber and sagnac loop mirror filter

We demonstrate a Q-switched Erbium-doped fiber laser (EDFL) with a tunable output wavelength using Nickel oxide (NiO) saturable absorber (SA) in conjunction with a Sagnac loop mirror (SLM) filter. The proposed SA was prepared by embedding NiO nanoparticles obtained bysimplistic sonochemical reaction into polyethylene oxide (PEO). The NiO PEO film was integrated into a figure-of-eight resonator configured with a SLM to generate Q-switched pulses with a tunable output wavelength. As the SLM temperature was increased from 30 °C to 70 °C, the laser operation can be tuned from 1551.9 nm to 1544.1 nm. At 1551.9 nm operation, the repetition rate rose from 36.2 kHz to 40.3 kHz and the pulse duration reduced from 10.00 to 9.32 μs when the pump power rose from 131.5 to 161.0 mW. At the highest pump power of 161.0 mW, the maximum output power and pulse energy were obtained at 0.67 mW and 16.6 nJ. For Q-switched operation at 1544.1 nm, the produced Q-switched pulse exhibited a pulse duration of 8.88 μs, the repetition rate of 45.7 kHz, the highest output power of 0.60 mW and pulse energy of 13.1 nJ at the maximum pump power of 161.0 mW.

Stable passively Q-switched erbium-doped fiber laser based on CuCrO2 nanoparticles saturable absorber

We demonstrate metal oxides CuCrO2 exhibit considerable nonlinear saturable absorption property in the near-infrared region, and fabricate typical saturable absorber (SA) by wrapping the CuCrO2 nanoparticles(NPs) into a sodium carboxymethylcellulose (NaCMC) film or polyimide (PI) film separately. These SA films could keep stable exposed to air condition for several months. In the CuCrO2-NaCMC (CuCrO2-PI) Q-switched fiber laser, the pulse repetition rate increases from 10.6 kHz (48.5 kHz) to 24.6 kHz (88.7 kHz) and the pulse duration decreases from 19.08μs (3.85μs) to 3.91μs (1.18μs) by adjusting the pump power from 53 mW (82.6 mW) to 188.6 mW (184.6 mW). The results suggest that CuCrO2 could be a promising SA for ultrafast lasers generation.

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.

56 nm Wide-Band Tunable Q-Switched Erbium Doped Fiber Laser with Tungsten Ditelluride (WTe2) Saturable Absorber

A wide-band and tunable Q-switched erbium-doped fiber (EDF) laser operating at 1560.5 nm with a tungsten ditelluride (WTe2) saturable absorber (SA) is demonstrated. The semi-metallic nature of WTe2 as well as its small band gap and excellent nonlinear optical properties make it an excellent SA material. The laser cavity uses an 89.5 cm long EDF, pumped by a 980 nm laser diode as the linear gain while the WTe2 based SA generates the pulsed output. The WTe2 based SA has a modulation depth, non-saturable loss and saturation intensity of about 21.4%, 78.6%, and 0.35 kW/cm2 respectively. Stable pulses with a maximum repetition rate of 55.56 kHz, narrowest pulse width of 1.77 µs and highest pulse energy of 18.09 nJ are obtained at the maximum pump power of 244.5 mW. A 56 nm tuning range is obtained in the laser cavity, and the output is observed having a signal to noise ratio (SNR) of 48.5 dB. The demonstrated laser has potential for use in a large number of photonics applications.

Tunable passively Q-switched erbium-doped fiber laser based on Ti3C2Tx MXene as saturable absorber

Abstract The passive generation of Q-switched pulses in an erbium-doped fiber (EDF) laser using a Ti3C2Tx MXene based saturable absorber (SA) was demonstrated. The SA was formed using Ti3AlC2 MAX phase as a precursor for Ti3C2Tx MXene which was obtained by etching Ti3AlC2 using a mixture of lithium fluoride and hydrochloric acid. The generated pulse output was obtained at a central wavelength of 1563 nm with a signal to noise ratio (SNR) of 51.1 dB at a pump power of 244.5 mW. Varying the pump power from 130.1 mW to 244.5 mW resulted in corresponding changes in the repetition rates and the pulse durations from 29.76 kHz to 48.74 kHz and 2.74 µs to 1.18 µs respectively. A pulse energy of 82.06 nJ was also obtained at the maximum pump power. Stable Q-switching could be observed up to 44 nm tuning range starting from 1532 nm to 1576 nm. The generated outputs indicated that the Ti3C2Tx based SA can generate high quality and stable Q-switched pulses in the EDF laser cavity, and has high potential for use in various optical telecommunications applications.

Low threshold Q-switched fiber laser incorporating titanium dioxide saturable absorber from waste material

We experimentally demonstrate a passively Q-switched erbium-doped fiber laser incorporating microfiber-based titanium dioxide (TiO2) polymer composite saturable absorber. The anatase TiO2 is derived from natural ilmenite waste via alkaline fusion method. The TiO2 polymer composite is prepared using solvent exchange method and deposited onto tapered microfiber via dip coating technique. The passive Q-switching at 1558.3 nm with low threshold pump power of 16.4 mW, average output power of 1.0 mW and pulse energy of 47.6 nJ are realized. The shortest pulse width of 7 μs with 22.56 kHz repetition rate is recorded. This work opens up a new window for the generation of microsecond pulses using waste material.

Q-switched Erbium-Doped Fiber Laser Incorporating Multi-Walled Carbon Nanotubes as a Saturable Absorber

We demonstrate the generation of Q-Switched erbium-doped fiber laser (EDFL) by employing a multi-walled carbon nanotubes-polyvinyl alcohol (MWCNTs-PVA) as a saturable absorber (SA). The SA was prepared by embedding MWCNTs into PVA via stirring and ultrasonication. A stable Q-Switched pulse train operating at 1559.4 nm was successfully generated by employing MWCNTs-PVA SA into a laser cavity. The repetition rate and pulse width of the laser were 52.85-151.9 kHz and 6.313-2.395 μs, respectively. The maximum output power and maximum peak power obtained are 52 μW and 142.94 μW, respectively at a pump power of 63 mW. This demonstration proves that the MWCNTs-PVA based SA is suitable for the generation of Q-Switched fiber laser at 1.55 μm region.

Generation of Q-switched Erbium-Doped Fiber Laser Using Titanium Dioxide Film Based Saturable Absorber

This work demonstrates a generation of a passively Q-switched erbium-doped fiber laser with titanium dioxide (TiO2) film as saturable absorber. The film is fabricated using a ratio of 2:1 by embedding the rutile nanoparticles (TiO2) into a polyvinyl alcohol (PVA) host film. Short after placing the SA film on the fiber ferrule, a stable 1563.3 nm pulses appeared at a power pump range from 104.62 mW to 145.83 mW. The maximum output power was recorded at 2.05 mW, inducing a maximum pulse energy of 22.63 nJ. The repetition rate shows an increasing trendline from 81.04 kHz to 90.58 kHz while the pulse width decreases from 5.08 μs to 4.12 μs. The high signal to noise ratio (SNR) of 63 dB indicates that the TiO2 film has a good performance in generating pulsed laser at 1550 nm wavelength.

Microsecond Pulse Generation using Bismuth Salenide as Saturable Absorber in 1.5 μm Region

A Q-switched Erbium-doped fiber laser (EDFL) was demonstrated utilizing Bismuth Salenide (Bi 2 Se 3) as a saturable absorber. The saturable absorber (SA) is fabricated by mixing directly the Bismuth Salenide (Bi 2 Se 3) into polyvinyl alcohol (PVA) aqueous solution to form a thin film. The SA is integrated into EDFL cavity to achieve a stable Q-switched at center wavelength of 1559.8 nm. The peak power is a steady increasing pattern from 2.52 mW to 3.21 mW as the pump power is increased from 86.1 mW to 116.6 mW. The highest pulse energy obtained was 36.9 nJ at the pump power of 116.6 mW.