Dual-wavelength Erbium-doped Fiber Research Articles

Stable dual-wavelength erbium-doped fiber laser using novel fabricated side-polished arc-shaped fiber with deposited ZnO nanoparticles

A dual-wavelength fiber laser operating at the 1550 nm region using a side-polished arc-shaped fiber with deposited ZnO nanoparticles is proposed and demonstrated. The arc-polished fiber is fabricated by using a simple but novel approach in which a silicon carbide paper polishes one side of a conventional single-mode fiber. An arc-polished fiber with a length of 2.25 mm and an insertion loss of 0.95 dB is obtained and deposited with ZnO nanoparticles by the drop-cast method. A stable dual-wavelength output is obtained at 1562.5 and 1563.4 nm at peak powers of −9.3 and −10.1 dBm, respectively, as well as a signal-to-noise ratio of 28.4 dB and a channel spacing of 0.9 nm. Both lasing wavelengths also have narrow linewidths of between 0.045 and 0.049 nm and show little to no wavelength or power fluctuations over continued testing.

Dual-wavelength passively Q-switched Erbium-doped fiber laser with MWCNTs slurry as saturable absorber

In this work, a compact, stable dual-wavelength Q-switched laser with a multi-walled carbon nanotubes (MWCNTs) slurry as saturable absorber (SA) which is independent of any host polymer has been demonstrated. The MWCNTs slurry is fabricated and the peak shift is investigated using Raman spectroscopy.The passively Q-switched erbium-doped fiber laser (EDFL) oscillated simultaneously at 1532.32 nm and 1556.97 nm with 24.67 nm peak separation, at threshold and maximum input power of 26mW and 74mW respectively.By increasing the input pump power from 36 mW to 74 mW, the pulse train repetition rate increases from 25 kHz to 78 kHz, while the pulse width is reduced from 17.84 us to 5.24 ?s. The generated pulse produced maximum pulse energy and maximum peak power of 11.97 nJ and 2.05 mW, respectively at maximum input pump power. The recorded signal to noise ratio is about 62 dB and shows that the proposed MWCNTs slurry based SAis able to generate dual wavelength Q-switched pulse laser with high stability pulse. Full Text: PDF ReferencesL.Liu, Z. Zheng, X. Zhao,S. Sun, Y. Bian, Y. Su, J. Liu, and J. Zhu, "Dual-wavelength passively Q-switched Erbium doped fiber laser based on an SWNT saturable absorber", Optics Communications 294, 267 (2013). CrossRef Z. Luo, M. Zhou, J. Weng, G. Huang, H. Xu, C. Ye, and Z. Cai, "Graphene-based passively Q-switched dual-wavelength erbium-doped fiber laser", Optics Letters 35, 3709 (2010). CrossRef F. Lou, R. Zhao, J. He, Z. Jia, X. Su, Z. Wang, J. Hou, and B. Zhang, "Nanosecond-pulsed, dual-wavelength, passively Q-switched ytterbium-doped bulk laser based on few-layer MoS2 saturable absorber", Photon. Res. 3, A25 (2015). CrossRef F. A. A. Rashid et al., "Using a black phosphorus saturable absorber to generate dual wavelengths in a Q-switched ytterbium-doped fiber laser", Laser Phys. Lett. 13, 1 (2016). CrossRef J. Sotor, G. Sobon, I. Pasternak, K. Krzempek, G. Dudzik, A. Krajewska, W. Strupinski, and K. M. Abramski, "Dual-wavelength fiber mode-locked laser based on graphene saturable absorber", Proc. of SPIE 8961, 89612A (2014). CrossRef S. Alwarappan, and A. Kumar, Graphene-Based Nanomaterials (Boca Rota, CRC Press 2014).N. Taib, N. Bidin, H. Haris, N. N. Adnan, M. Ahmad, and S. W. Harun, "Multi-walled carbon nanotubes saturable absorber in Q-switching flashlamp pumped Nd:YAG laser", Optics & Laser Technology 79, 193 (2016). CrossRef M. Ahmad, A. Latiff, Z. Zakaria, and S. Harun, "Q-Switched Ultrafast TDFL Using MWCNTs-SA at 2 ?m Region", International Journal of Computer and Communication Engneering 3, 446 (2014). CrossRef H. Ahmad, K. Z. Hamdan, F. D. Muhammad, S. W. Harun, and M. Z. Zulkifli, "Switchable dual-wavelength CNT-based Q-switched using arrayed waveguide gratings (AWG)", Applied Physics B 118, 269 (2015). CrossRef J. M. Dudley and J. R. Taylor, Supercontinuum Generation in Optical Fibres (New York, Cambridge University Press 2010). CrossRef H. Ahmad, M. A. M. Salim, M. R. K. Soltanian, S. R. Azzuhri, and S. W. Harun, "Passively dual-wavelength Q-switched ytterbium doped fiber laser using Selenium Bismuth as saturable absorber", Journal of Modern Optics 62, 1550 (2015). CrossRef H. Chu et al., "Dual-Wavelength Passively Q-Switched Nd,Mg:LiTaO3 Laser With a Monolayer Graphene as Saturable Absorber", IEEE Journal of Selected Topics in Quantum Electronics 21, 1600705 (2015). CrossRef Z. T. Wang, Y. Chen, C. J. Zhao, H. Zhang, and S. C. Wen, "Switchable Dual-Wavelength Synchronously Q-Switched Erbium-Doped Fiber Laser Based on Graphene Saturable Absorber", IEEE Photonics Journal 4, 869 (2012). CrossRef J. H. Liu et al., "Passively Q-switched dual-wavelength Yb:LSO laser based on tungsten disulphide saturable absorber", Chin. Phys. B 25, 034207 (2016). CrossRef Z. C. Tiu et al, "Multi-wavelength Q-switched Erbium-doped fiber laser with photonic crystal fiber and multi-walled carbon nanotubes", Journal of Modern Optics 61, 1133 (2014). CrossRef

Stability wavelength-spacing-tunable single-longitudinal-mode dual-wavelength erbium-doped fiber laser based on nonlinear amplifying loop mirror

A simple linear cavity configuration for a stability wavelength-spacing-tunable single-longitudinal-mode (SLM) dual-wavelength erbium-doped fiber laser based on a nonlinear amplifying loop mirror (NALM) is proposed. The gain competition in the erbium-doped fiber (EDF) has been suppressed by the intensity dependent loss introduced by the NALM. The SLM operation is guaranteed by a section of unpumped EDF as saturable absorber. A stable dual-wavelength SLM fiber laser with a wavelength-spacing of 11.35 nm is experimentally realized. The optical signal-to-noise ratio is over 47 dB and the linewidths of two wavelengths measured by delayed self-heterodyne method are 1.1 and 1.0125 kHz, respectively. The tuning range of wavelength-spacing is 9.09–11.35 nm, correspondingly, and the THz signal is from 1.235 to 1.416 THz.

All-fiber dual-wavelength Q-switched and mode-locked EDFL by SMF-THDF-SMF structure as a saturable absorber

We demonstrate all-fiber dual-wavelength Q-switched and mode-locked erbium-doped fiber laser (EDFL) by utilizing the thulium-holmium-doped fiber (THDF) as a fiber saturable absorber (SA) and also a Mach-Zehnder interferometer (MZI) element. The 19cm long THDF has a core diameter of 11.5µm, refractive index difference of 0.005, and cutoff wavelength of 1810nm. Stable dual-wavelength Q-switching operation was generated at 1555.14nm and 1557.64nm with free spectral range (FSR) of 2.5nm. The repetition rate of 14.45–78.49kHz was obtained between 12 and 100mW pump power. At maximum pump power, the maximum output power and pulse energy were 2.58mW and 32.87 nJ, respectively. By adding 195cm long SMF in the same cavity, the stable dual-wavelength mode-locking operation was started at 166mW and continue stable to 201mW pump power. This mode-locking operation produced stable dual-wavelength pulses at 1530.34nm and 1532.84nm with a repetition rate of 1MHz with a pulse duration of 128ns and signal-to-noise ratio (SNR) of 62dB. It shares the same value of FSR in Q-switching operation. The highest output power of 1.57 nJ corresponds to the maximum output power of 1.57mW was obtained. Our results validate the linear absorption characteristic at C-band region and multimode fiber effect of THDF can be utilized as SA to generate stable all-fiber dual-wavelength pulsed lasers. Remarkably, these findings expand a fiber gain medium application in short pulse generation.

Switchable dual-wavelength erbium-doped fibre laser utilizing two-channel fibre Bragg grating fabricated by femtosecond laser

We propose and demonstrate a switchable dual-wavelength erbium-doped fibre ring laser. Competition between the lasing wavelengths in erbium-doped fibre laser at room temperature is suppressed by incorporating a two-channel fibre Bragg grating (TC-FBG), which consists of two highly localized sub-gratings fabricated by femtosecond laser in single mode fibre. Wavelengths and polarization states of the lasing lines are selected by the TC-FBG. Laser output can be switched between single- and dual-wavelength operations by simply adjusting the polarization controller. Stable dual-wavelength output is verified at room temperature with a power fluctuation less than 0.27 dB, and wavelength fluctuation less than 0.004 nm.

Widely tunable single-/dual-wavelength fiber lasers with ultra-narrow linewidth and high OSNR using high quality passive subring cavity and novel tuning method.

High stability single- and dual-wavelength compound cavity erbium-doped fiber lasers (EDFLs) with ultra-narrow linewidth, high optical signal to noise ratio (OSNR) and widely tunable range are demonstrated. Different from using traditional cascaded Type-1/Type-2 fiber rings as secondary cavities, we nest a Type-1 ring inside a Type-2 ring to form a passive subring cavity to achieve single-longitudinal-mode (SLM) lasing with ultra-narrow linewidth for the first time. We also show that the SLM lasing stability can be further improved by inserting a length of polarization maintaining fiber in the Type-2 ring. Using a uniform fiber Bragg grating (FBG) and two superimposed FBGs as mode restricting elements, respectively, we obtain a single-wavelength EDFL with a linewidth as narrow as 715 Hz and an OSNR as high as 73 dB, and a dual-wavelength EDFL with linewidths less than 1 kHz and OSNRs higher than 68 dB for both lasing wavelengths. Finally, by employing a novel self-designed strain adjustment device capable of applying both the compression and tension forces to the FBGs for wavelength tuning, we achieve the tuning range larger than 10 nm for both of the EDFLs.

Tunable and switchable dual-wavelength erbium-doped fiber laser based on in-line tapered fiber filters

A tunable and switchable dual-wavelength erbium-doped fiber laser (EDFL) based on all-fiber single-mode tapered fiber structure has been demonstrated. By adjusting the variable optical attenuator (VOA), the laser can be switched between the single-wavelength mode and the dual-wavelength mode. When the temperature applied on the tapered fiber structure varies, the pass-band varies and the wavelength of the output laser shifts correspondingly. When the temperature changes from 30 °C to 180 °C, the central wavelength of the EDFL generated by branch A shifts from 1 550.7 nm to 1 560.3 nm, while that of branch B shifts from 1 530.8 nm to 1 540.4 nm, indicating the wavelength interval is tunable. These advantages enable this laser to be a potential candidate for high-capacity wavelength division multiplexing systems and mechanical sensors.

Development of dual-wavelength fiber ring laser and its application to step-height measurement using self-mixing interferometry.

A dual-wavelength erbium-doped fiber (EDF) ring laser was developed and its application to step-height measurement using two-wavelength self-mixing interferometry (SMI) was demonstrated. The fiber laser can emit two different wavelengths without any laser mode competition. It is composed of two EDF laser cavities and employs fiber Bragg gratings to determine which wavelengths are emitted. The step heights can be measured using SMI of the two wavelengths, and the maximum height that can be measured is half the synthetic wavelength of the two wavelengths. A step height of 1mm was constructed using two gauge blocks and then measured using the laser. The measurement was repeated ten times, and the standard deviation of the measurements was 2.4nm.

Single-/dual-wavelength switchable and tunable compound-cavity erbium-doped fiber laser with super-narrow linewidth

A single-/dual-wavelength switchable and tunable erbium-doped fiber laser (EDFL) with super-narrow linewidth has been proposed and experimentally demonstrated at room temperature. The fiber laser is based on a compound cavity simply composed of a ring main cavity and a two-ring subring cavity (TR-SC). Regardless of single- or dual-wavelength operation, the EDFL could always work well in single-longitudinal-mode (SLM) state at every oscillating wavelength. In dual-wavelength operation, the spacing could be tuned from 0 nm to 4.83 nm. In single-wavelength operation, the EDFL could lase at a fixed wavelength of 1 543.65 nm or another wavelength with a tunable range of 4.83 nm. The super-narrow linewidths of 550 Hz and 600 Hz for two wavelengths are obtained. The proposed EDFL has potential applications in microwave/terahertz-wave generation and high-precision distributed fiber optical sensing.

Selectable dual-wavelength erbium-doped fiber laser with stable single-longitudinal-mode utilizing eye-type compound-ring configuration

In this paper, a tunable dual-wavelength erbium-doped fiber (EDF) ring laser with stable single-longitudinal-mode (SLM) under a tuning range of 1530.0–1560.0nm is proposed and demonstrated. Here, the mode spacing of lasing dual-wavelength from 1.0 to 30.0nm can be selected arbitrarily in any wavelength position. To accomplish the SLM output, the eye-type compound-ring scheme is proposed inside ring cavity for suppressing the multi-longitudinal-mode (MLM) highly. The entire measured output power and optical signal to noise ratio (OSNR) of each dual-wavelength are larger than −13.3dBm and 60dB respectively. In addition, the output stability measurement of proposed EDF laser is also performed and analyzed.

Erbium-doped fiber triple-ring laser configuration with single-longitudinal-mode dual-wavelength output

In this investigation, we propose and demonstrate a stabilized single-longitudinal-mode (SLM) dual-wavelength erbium-doped fiber (EDF) laser triple-ring cavity. Here, two fiber Bragg gratings (FBGs) are used inside the fiber cavity to generate dual-wavelength output. In order to complete the SLM output, the triple-ring configuration is utilized for suppressing the densely multi-longitudinal mode (MLM). The output powers and wavelengths of −8.4 and −8.5 dBm and 1535.76 and 1543.28 nm are obtained in the proposed dual-wavelength EDF laser, respectively. Moreover, the stability performances of output power and wavelength in the proposed EDF laser are also discussed.

Stabilized dual-wavelength erbium-doped fiber laser with a single-longitudinal mode by utilizing fiber Bragg grating and a compound-ring filter

In this investigation, a stable single-longitudinal-mode (SLM) dual-wavelength erbium-doped fiber (EDF) multiring laser by utilizing fiber Bragg grating is proposed and investigated. Here, to accomplish a SLM output, the multiring cavity of the proposed EDF laser is employed for suppressing the densely multilongitudinal mode. Hence, the output powers and wavelengths of the proposed dual-wavelength EDF laser are 7.0 and 6.7 dBm and 1531.72 and 1537.32 nm, respectively. In addition, the maximum output stabilities of the power and wavelength in the proposed laser are also executed and discussed.

Stable Dual-Wavelength Coherent Source With Tunable Wavelength Spacing Generated By Spectral Slicing a Mode-Locked Laser Using Microring Resonator

We demonstrate a stable tunable dual-wavelength erbium-doped fiber laser generated by launching a mode-locked laser into an add–drop microring resonator. Two silicon-based high-index-contrast microring resonators with $Q$ -factors of 1.2 × 10 5 and 0.6 × 10 5 have been used as add–drop filters independently. As a result, multiwavelength generation was achieved and demonstrated both theoretically and experimentally with free spectral range (FSR) of 0.202 and 0.404 nm corresponding to the microrings' diameter of $\textrm{D}=2.54$ and $\textrm{D}=1.27\,\mbox{mm}$ . A high-resolution tunable bandpass filter and fiber Bragg gratings (FBGs) are then used to extract a tunable and switchable dual-wavelength coherent source from the generated multiwavelength coherent source. Subsequently, the dual-wavelength coherent source with tunable FSRs from 0.404 to 3.232 nm is achieved and presented. The obtained dual-wavelength output has a side-mode suppression ratio of more than 30 dB.

Low-threshold dual-wavelength erbium-doped fiber laser based on ring core fiber with core-offset structure

A low-threshold dual-wavelength erbium-doped fiber laser is proposed and tested in an experiment. The filter is based on a ring-core fiber with a core-offset structure. The threshold of the laser is as low as 16 mW. The operating wavelengths are 1560.02 and 1564.75 nm, respectively. Meanwhile, both of the side-mode suppression ratios of the operation wavelengths are higher than 50 dB when the pump power is 100 mW. In addition, the strain sensitivities are 0.7574 and 0.6676 pm με−1, respectively.

Dual-Wavelength Erbium-Doped Fiber Laser to Generate Terahertz Radiation Using Photonic Crystal Fiber

We demonstrate a widely tunable dual-wavelength erbium-doped fiber laser that used a 10-cm photonic crystal fiber as a Mach–Zehnder interferometer to filter out the switchable dual-wavelength signals so as to generate tunable continuous-wave (CW) terahertz (THz) radiation. Each single longitudinal mode wavelength could be independently tuned by using a tunable band-pass filter and polarization controller (PC). The wavelength fine-tuning was achieved via adjustments to the PC, and the resulting dual-wavelength output had a side-mode suppression ratio (SMSR) of more than 30 dB. The wavelength spacing of 7, 11.4, and 21.2 nm, corresponding to 0.9, 1.4, and 2.66 THz radiation, respectively, was tuned in order to obtain CW THz radiation. This CW THz radiation was produced by means of a stable dual-wavelength fiber laser performing as the optical beat source, together with a DAST crystal-based photomixer. High-sensitivity thermal sensors calibrated for THz radiation were able to continuously detect the emitted CW THz radiation.

A switchable and stable single-longitudinal-mode, dual-wavelength erbium-doped fiber laser assisted by Rayleigh backscattering in tapered fiber

We have proposed and demonstrated a novel switchable single-longitudinal-mode (SLM), dual-wavelength erbium-doped fiber laser (DWEDFL) assisted by Rayleigh backscattering (RBS) in a tapered fiber in a ring laser configuration. The RBS feedback in a tapered fiber is a key mechanism as linewidth narrowing for laser output. A compound laser cavity ensured that the EDFL operated in the SLM state and a saturable absorber (SA) is employed to form a gain grating for both filtering and improving wavelength stability. The fiber laser can output dual wavelengths simultaneously or operate at single wavelength in a switchable manner. Experiment results show that with the proper SA, the peak power drift was improved from 1–2 dB to 0.31 dB and the optical signal to noise ratio was higher than 60 dB. Under the assistance of RBS feedback, the laser linewidths are compressed by around three times and the Lorentzian 3 dB linewidths of 445 Hz and 425 Hz are obtained at 1550 nm and 1554 nm, respectively.

Switchable dual-wavelength erbium-doped fiber laser with tunable wavelength

A switchable dual-wavelength erbium-doped fiber laser (EDFL) with tunable wavelength is demonstrated. The ring cavity consists of two branches with a fiber Bragg grating (FBG) and a spherical-shape structure as fiber filters, respectively. By adjusting the variable optical attenuator (VOA), the laser can be switched between the single-wavelength mode and the dual-wavelength mode. The spherical-shape structure has good sensitivity to the temperature. When the temperature changes from 30 °C to 190 °C, the central wavelength of the EDFL generated by the branch of spherical-shape structure varies from 1 551.6 nm to 1 561.8 nm, which means that the wavelength interval is tunable.

Stable and switchable single-longitudinal-mode dual-wavelength erbium-doped fiber laser based on a fiber ring filter

A switchable dual-wavelength and single-longitudinal-mode (SLM) erbium-doped fiber laser (EDFL) based on a fiber ring filter (FRF) is proposed and demonstrated through a detailed experimental verification. In the design, the simple linear-cavity EDFL is composed of one 976-nm laser diode (LD), one fiber loop mirror (FLM), two cascaded fiber Bragg gratings (FBGs), and an EDF. To improve the laser stability, the FRF is spliced into a specially designed EDFL, which is fabricated from an EDF and two couplers with splitting ratios of 50:50 and 30:70, respectively. Both single- and dual-wavelength lasers can be realized by adjusting the variable attenuator (VA) between the two FBGs. In the proposed EDFL, the 1540-nm laser and the 1545-nm laser, respectively, incur laser-frequency shifts at room temperature of less than 3 pm and 2 pm over a period of 60min. The single-wavelength 1540- and 1545-nm lasers show single-longitudinal-mode (SLM) operation within the frequency range of 0–500MHz, as measured by the delayed self-heterodyne method using a 50-km single-mode fiber, and the 3-dB linewidths of the output of two lasers are about 2.8kHz and 2.5kHz, respectively.

Dual-wavelength rectangular pulse erbium-doped fiber laser based on topological insulator saturable absorber

We reported on the generation of the dual-wavelength rectangular pulse in an erbium-doped fiber laser (EDFL) with a topological insulator saturable absorber. The rectangular pulse could be stably initiated with pulse width from 13.62 to 25.16 ns and fundamental repetition rate of 3.54 MHz by properly adjusting the pump power and the polarization state. In addition, we verified that the pulse shape of the dual-wavelength rectangular pulse can be affected by the total net cavity dispersion in the fiber laser. Furthermore, by properly rotating the polarization controllers, the harmonic mode-locking operation of the dual-wavelength rectangular pulse was also obtained. The dual-wavelength rectangular pulse EDFL would benefit some potential applications, such as spectroscopy, biomedicine, and sensing research.

基于光纤环形滤波器的双波长掺铒光纤激光器

基于光纤环形滤波器的双波长掺铒光纤激光器