Bismuth-based Erbium-doped Fiber Research Articles

Mode-locked Thulium Ytterbium co-Doped Fiber Laser with Graphene Saturable Absorber

A passively mode-locked Thulium Ytterbium co-doped fiber laser (TYDFL) is demonstrated using a graphene polyvinyl alcohol saturable absorber as the mode-locker. With 980 nm multimode pumping, the laser operates at 1942.95 nm with repetition rate of 11.76 MHz. The pulse width is calculated to be around 52.85 ps. The maximum pulse energy of 1190.5 pJ is achieved at pump power of 1750 mW. Full Text: PDF ReferencesJ. Sotor et al., "Ultrafast thulium-doped fiber laser mode locked with black phosphorus", Opt. Lett. 40, 3885-3888 (2015) CrossRef J. Wang et al., "152 fs nanotube-mode-locked thulium-doped all-fiber laser", Nature Scientific Reports 6, 28885 (2016) CrossRef I. M. Babar et al., "Double-clad thulium/ytterbium co-doped octagonal-shaped fibre for fibre laser applications", Ukr. J. Phys. Opt. 15, 173-183 (2014) CrossRef Harun et al., "Mode-locked bismuth-based erbium-doped fiber laser with stable and clean femtosecond pulses output", Laser Phys. Lett. 8, 449-452 (2011) CrossRef M. A. Ismail et al., "Nanosecond soliton pulse generation by mode-locked erbium-doped fiber laser using single-walled carbon-nanotube-based saturable absorber", Applied Optics 51, 8621-8624 (2012) CrossRef G. Sobon et al., "Graphene Oxide vs. Reduced Graphene Oxide as saturable absorbers for Er-doped passively mode-locked fiber laser", Opt. Express 20, 19463-19473 (2012) CrossRef G. Sobon et al., "Thulium-doped all-fiber laser mode-locked by CVD-graphene/PMMA saturable absorber", Opt. Express 21, 12797-12802 (2013) CrossRef

Sideband-controllable soliton pulse with bismuth-based erbium-doped fiber

A sideband-controllable soliton mode-locked erbium-doped fiber laser is successfully demonstrated utilizing the nonlinear polarization rotation technique. The sidebands can be produced or suppressed by performing simple polarization light tuning with a polarization controller. It is believed that the elimination of the sidebands is due to the dispersive waves that are filtered out by the polarization-dependent isolator in the resonator. With the elimination of the Kelly sidebands, the obtained 3 dB bandwidth is 10.6 nm and the attainable pulse duration is 0.86 ps. In this experiment, it is proven that the existence of Kelly sidebands limits the attainable pulse duration.

Effective use of an EDFA and Raman pump residual powers via a Bi-EDF in L-band multi-wavelength fiber laser generation

Residual powers of an erbium-doped fiber amplifier (EDFA) and a Raman pump are utilized effectively for pumping a 0.45 m long bismuth-based EDF (Bi-EDF) in linear-cavity L-band multi-wavelength fiber laser generation. A 7.7 km dispersion compensating fiber (DCF) operates as both Brillouin and Raman gain media and a 6.5 dBm fixed-power tunable laser source (TLS) amplified by an EDFA works as a Brillouin pump (BP). By inserting the Bi-EDF in the linear cavity and using the EDFA and the fixed Raman pump residual powers 13.6 mW and 64 mW, at wavelengths 978.8 nm and 1490.6 nm respectively, the gain spectrum is inhomogeneously broadened so that linewidth of the gain spectrum is expanded from 3.4 to 12.3 nm. As a result, the number of lines of an L-band multi-wavelength fiber laser (MFL) is increased noticeably. In addition, the number of lines at a BP wavelength 1590.6 nm decreased from 38 to 32 by using the maximum EDFA pump residual power of 44 mW due to a reduction in the quantum coefficient efficiency. However, flatness and stability characteristics of the MFL are improved. The MFL can be generated in the wavelength region 1570–1610 nm with the signal to noise ratio of about 42.

Wavelength-Tunable and Bandwidth-Variable Ultra-Flat Optical Frequency Comb Block Generation From a Bismuth-Based Actively Mode-Locked Fiber Laser

We generate, for the first time and to the best of our knowledge, a tunable ultra-flat optical frequency comb (OFC) block from a 10-GHz bismuth-based actively mode-locked fiber laser. A bismuth-based erbium-doped fiber (Bi-EDF) with a length of 1.5 m and a bismuth-based highly nonlinear fiber (Bi-HNLF) with a length of 4.1 m are used as a gain medium and a spectral broadening device, respectively. We also employ a wavelength-tunable and bandwidth-variable optical filter for an intracavity filter. The center wavelength of the OFC output can be widely tuned from 1535 to 1585 nm because the Bi-EDF has a broadband gain profile. A spectrally broadened ultra-flat OFC is successfully generated by the self-phase modulation in the Bi-HNLF. By tuning the filter bandwidth, the 10-dB spectral width and the pulsewidth of the generated OFC can be widely varied from 0.23 to 2.4 nm and from 3 to 20.1 ps, respectively. The fiber ring cavity is as short as 17.8 m. For the entire tuning ranges, the proposed bismuth-based tunable ultra-flat OFC generator also realizes stable bit-error-free mode-locking operation.

In Vivo OCT Imaging Based on La-Codoped Bismuth-Based Erbium-Doped Fiber

We demonstrate a Fourier domain mode-locked laser based on lanthanum-codoped bismuth-based erbium-doped fiber (Bi-EDF) for swept source optical coherence tomography (SS-OCT) imaging. Raman amplification is incorporated to suppress the gain competition and homogenous linewidth broadening effects of Bi-EDF. A wavelength sweeping bandwidth of 81 nm is generated under stable operation. Therefore, in vivo OCT imaging of human finger print and orange slices is enabled and the results are also presented. This scheme paves the way for doped fiber amplifiers to be employed to generate ultra-wideband SSs for OCT applications.

Widely tunable L-band multiwavelength brillouin-erbium fiber laser incorporating a bismuth-based erbium-doped fiber

We have demonstrated a widely wavelength tunable Brillouin-erbium fiber laser (BEFL) with multiwavelength lasing in the L-band region. The Brillouin pump (BP) is injected from the external cavity and preamplified by an intracavity bismuth-based erbium-doped fiber amplifier (Bi-EDFA) before entering the single-mode fiber. By combining the broadband gain of Bi-EDFA and BP preamplification technique within the linear cavity, our BEFL exhibits a broad tuning range of 65 nm from 1555 to 1620 nm, which is the widest one achieved in L-band BEFLs to the best of our knowledge. The maximum number of wavelengths obtained within this wavelength range is 12 channels with a spacing of approximately 0.088 nm. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1574–1577, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27664

OPTICAL AMPLIFIER WITH FLAT-GAIN AND WIDEBAND OPERATION UTILIZING HIGHLY CONCENTRATED ERBIUM-DOPED FIBERS

In this paper, we proposed a flat-gain and wide-band erbium doped fiber amplifier (EDFA) using two chirped fiber Bragg grating (CFBG) in serial configuration for double-pass operation. The amplifier consists of two sections of Erbium-doped fiber (EDF) operating in C-band and L-band respectively. A CFBG is used in each section to reflect the amplified signal back to the active area so that the overall gain spectrum can be enhanced and flattened. It is also observed that the gain of the amplifier produces a relatively higher gain with the Bismuth-based EDF (Bi-EDF) in the first stage compared to that of silica-based EDF (Si-EDF), especially in a longer wavelength region. The small signal gain of more than 19 dB is obtained within a wavelength region from 1545 to 1605 nm by the use of Bi-EDF with a small noise figure penalty. With a Si-EDF, the flat gain spectrum is observed within a wavelength region ranging from 1535 nm to 1605 nm with a gain variation of less than 2 dB at input signal of 0 dBm. This shows that the proposed serial double-pass amplifier may find its broad applications in wavelength division multiplexing long-haul systems as well as local optical networks.

A Band-Separated, Bidirectional Amplifier Based on Erbium-Doped Bismuth Fiber for Long-Reach Hybrid DWDM–TDM Passive Optical Networks

We propose a band-separated, bidirectional amplifier based on a bismuth-based erbium-doped fiber for use in long-reach hybrid dense wavelength division multiplexing-time division multiplexing passive optical networks (DWDM-TDM-PONs). We also propose a long-reach hybrid DWDM-TDM-PON architecture in which the proposed amplifier can be effectively used. The feasibility of using the proposed amplifier for long-reach hybrid DWDM-TDM-PONs is experimentally investigated by performing a series of signal transmission experiments with an exemplary PON configuration having a total reach of 75 km and 8 split users. Error-free bidirectional signal transmission at a line rate of 10 Gbit/s is successfully demonstrated. A theoretical investigation also shows that the reach/split limitation issue associated with an insufficient WDM signal gain in the experimental demonstration can be easily solved by optimizing the amplifier.

Supercontinuum generation using a passive mode-locked stretched-pulse bismuth-based erbium-doped fiber laser

A Supercontinuum (SC) generation in photonic crystal fiber (PCF) is demonstrated using an amplified picosecond stretched-pulses from a passive mode-locked Bismuth-based Erbium-doped fiber laser (Bi-EDFL). The Bi-EDFL employs of a piece of a highly nonlinear 49 cm long Bismuth-based Erbium-doped fiber (Bi-EDF), an optical isolator and a polarization controller in a cavity to generate a mode-locked stretched-pulse via a nonlinear polarization rotation technique. It operates at 1560 nm with a repetition rate of 42 MHz and a pulse width of 131 fs. The SC lights, which extends from 1250 nm to 1910 nm as well as in the visible green wavelength region are obtained with a 100 m long PCF and the amplified pump power of 30 dBm.

Highly efficient short length Bismuth-based erbium-doped fiber amplifier

An efficient 21 cm Bismuth-based erbium doped fiber amplifier (Bi-EDFA) operating in both C- and L-band wavelength regions is proposed and demonstrated. The proposed Bi-EDFA uses the gain medium with an erbium ion concentration of 6300 ppm in conjunction with a double-pass configuration. Compared to conventional silica-based erbium-doped fiber amplifiers (Si-EDFAs) with the same amount of Erbium ions, the Bi-EDFA provides a higher attainable gain as well as a greater amplification bandwidth ranging from 1525 to 1620 nm. The proposed Bi-EDFA achieved a flat-gain of around 23 dB with gain variation of ±3.5 dB within the wavelength region from 1530 to 1565 nm at the maximum pump power of 150 mW. The corresponding noise figures are obtained at an average of 6 dB.

Multiwavelength L-band fiber laser with bismuth-oxide EDF and photonic crystal fiber

A multiwavelength laser comb using a bismuth-based erbium-doped fiber and 50 m photonic crystal fiber is demonstrated in a ring cavity configuration. The fiber laser is solely pumped by a single 1455 nm Raman pump laser to exploit its higher power delivery compared to that of a single-mode laser diode pump. At 264 mW Raman pump power and 1 mW Brillouin pump power, 38 output channels in the L-band have been realized with an optical signal-to-noise ratio above 15 dB and a Stokes line spacing of 0.08 nm. The laser exhibits a tuning range of 12 nm and produces stable Stokes lines across the tuning range between Brillouin pump wavelengths of 1603 nm and 1615 nm.

Investigation on stimulated Brillouin scattering characteristics in a highly doped Bismuth-based Erbium-doped fiber

Stimulated Brillouin scattering (SBS) characteristics in a 49 cm long highly doped Bismuth-based Erbium doped fiber (Bi-EDF) is investigated in the ring and linear cavity configurations. At Brillouin pump (BP) power of 6 dBm, the Brillouin laser peak power of the optimized ring Brillouin Erbium fiber laser (BEFL) is obtained at 23 dB higher than the peak power of the conventional linear cavity at an up shifted wavelength of 0.08 nm. This Bi-EDF ring cavity operates at nearly 1563 nm wavelength region, which is up-shifted by 0.08 nm from the Brillouin pump wavelength with the side mode suppression ratios (SMSR) of 29 and 23 dB in the forward and backward directions, respectively.

Performance comparison of Zr-based and Bi-based erbium-doped fiber amplifiers

In this Letter, we present a comprehensive comparison of the performance of a zirconia-based erbium-doped fiber amplifier (Zr-EDFA) and a bismuth-based erbium-doped fiber amplifier (Bi-EDFA). The experimental results reveal that a Zr-EDFA can achieve comparable performance to the conventional Bi-EDFA for C-band and L-band operations. With a combination of both Zr and Al, we could achieve a high erbium-doping concentration of about 2800 ppm (parts per million) in the glass host without any phase separations of rare earths. The Zr-based erbium-doped fiber (Zr-EDF) was fabricated using in a ternary glass host, zirconia-yttria-aluminum codoped silica fiber through a solution-doping technique along with modified chemical vapor deposition. At a high input signal of 0 dBm, a flat gain at average value of 13 dB is obtained with a gain variation of less than 2 dB within the wavelength region of 1530-1575 nm and using 2 m of Zr-EDF and 120 mW pump power. The noise figures are less than 9.2 at this wavelength region. It was found that a Zr-EDFA can achieve even better flat-gain value and bandwidth as well as lower noise figure than the conventional Bi-EDFA.

Investigation of signal excited-state absorption in bismuth-based erbium-doped fiber amplifier

Signal excited-state absorption (ESA) in a bismuth oxide-based erbium-doped fiber (EDF) amplifier was investigated in numerical and experimental ways. The signal ESA cross-section of the bismuth oxide-based EDF was first measured by using a especially devised numerical-prediction technique that can give an accurate value for an arbitrary EDF length. Using a range of numerical simulations based on the measured signal ESA cross-section as well as experimental measurements, the signal ESA’s impact on the gain and noise figure was investigated. The signal ESA reduces the amplification bandwidth by ∼7 nm compared with that of the theoretical gain bandwidth that can be obtained without signal ESA. The longer wavelength limit of the amplification band was estimated to be ∼1632 nm.

FWM-based multi-wavelength erbium-doped fiber laser using Bi-EDF

We experimentally demonstrate a simple structure but efficient multi-wavelength erbium-doped fiber laser (EDFL) using a 49 cm Bismuth-based erbium-doped fiber (Bi-EDF) as gain medium. The Bi-EDF provides erbium amplification and FWM effect in the cavity to generate a stable multi-wavelength comb operating in C-band region. We have achieved more than 5 lines with peak power of more than −35 dBm and channel spacing of 0.5 nm by incorporating a broadband fiber Bragg grating and polarization controller in the ring cavity.

Broadband ASE source using bismuth-based erbium-doped fibers in double-pass set-up

Flat and broadband amplified spontaneous emission (ASE) spectrum, which covers both C and L-band regions is demonstrated. The ASE source employs 49 and 215 cm long Bismuth-based erbium-doped fiber (Bi-EDF) to provide C- and L-band amplifications, respectively as gain media in conjunction with double-pass linear configuration. The ASE power level obtained varies from -24 to -35 dBm within 85 nm bandwidth from 1530 to 1615 nm at the optimum pump powers combination. The total ASE power reaches up to 26 mW at maximum total pump power of 320 mW, which can be translated to 8% efficiency. (C) 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1636-1638, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25239

Multi-wavelength bismuth-based erbium-doped fiber laser based on four-wave mixing effect in photonic crystal fiber

A stable multi-wavelength erbium-doped fiber laser based on four-wave mixing (FWM) in a photonic crystal fiber (PCF) is demonstrated in this paper. The phase matching condition for four-wave mixing in the photonic crystal fiber has been enhanced using a seed signal and a polarisation controller to control the states of polarisation in the ring laser cavity. At a maximum pump power of 1480 nm, 5 lines are observed with nearly 2.15 nm spacing between the lines, and with a signal to noise ratio of more than 20 dB. The number of channels and wavelength spacing can be controlled by varying the output coupler ratio.

Multiple Brillouin Stokes generation with bismuth‐based erbium‐doped fiber

AbstractA multiple Brillouin Stokes generation is demonstrated at extended L‐band region using the bismuth‐based erbium‐doped fiber (Bi‐EDF) in the linear cavity. A 2.15‐m long Bi‐EDF is used to provide both nonlinear and linear gains to generate a stimulated Brillouin scattering (SBS) and to amplify the generated SBS, respectively. The Brillouin erbium fiber laser operates at 1615 nm region with more than 40 Stokes and anti‐Stokes lines, and the line spacing is measured to be ∼0.09 nm. Based on the four‐wave mixing signals spacing, the dispersion coefficient of the Bi‐EDF is estimated to be ∼95 ps/nm/km. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1416–1418, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25207

Bismuth-based erbium-doped fiber as a gain medium for L-band amplification and Brillouin fiber laser

Bismuth-based erbium-doped fiber (Bi-EDF) is demonstrated as an alternative medium for optical amplification and nonlinear applications. The bismuth glass host provides the opportunity to be doped heavily with erbium ions to allow a compact optical amplifier design. The bismuth-based erbium-doped fiber amplifier (Bi-EDFA) is demonstrated to operate at wavelength region from 1570 to 1620 nm using only a 215 cm long of gain medium. The maximum gain of 15.8 dB is obtained at signal wavelength of 1610 nm with the corresponding noise figure of about 6.3 dB. A multi-wavelength laser comb is also demonstrated using a stimulated Brillouin scattering in the 215 cm long Bi-EDF assisted by the 1480 nm pumping. The laser generates more than 40 lines of optical comb with a line spacing of approximately 0.08 at 1612.5 nm region using 152 mW of 1480 nm pump power.

Experimental and theoretical studies on a double-pass C-band bismuth-based erbium-doped fiber amplifier

Performance of a Bismuth-based Erbium-doped fiber amplifier is experimentally and theoretically investigated using 1480 nm pumping with double-pass scheme. In the theoretical analysis, the rate and power propagation equations are solved to examine the optimum length for the C-band operation as well as the gain and noise figure characteristics. The calculated small signal gain is 38 dB with gain variation of less than 3 dB. The measured gain is 4 dB lower due to spurious reflections which were ignored in the theoretical analysis. At input signal power of 0 dBm, a gain of 14.5 dB is obtained experimentally with gain variation of less than 1 dB within the wavelength region from 1530 to 1565 nm. The noise figure is less than 12 dB within this region.