Bismuth-based Erbium-doped Fiber Amplifier Research Articles

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

Multiple wavelength generation using a compacted hybrid Raman / Bi-EDF amplifier

A multiple wavelength laser source is generated by a Brillouin seed signal and a compacted hybrid Raman / bismuth-based erbium doped fiber amplifier (Bi-EDFA) in a linear cavity. The gain media of the Raman/Bi-EDFA is only a 2.15 m Bi-EDF pumped bi-directionally by two laser diodes (LDs). In comparison to all of the conventional multiple wavelength sources generated via using the same Bi-EDF and LDs, the proposed multiple wavelength source has much more number of lines due to using Raman and EDF amplification.

Optical frequency comb generation using a new compacted hybrid Raman Bi-based erbium doped fiber amplifier in a linear cavity

A new compacted hybrid Raman bismuth-based erbium doped fiber amplifier (Bi-EDFA) is demonstrated to generate an optical frequency comb source via Brillouin seed signals. A highly nonlinear Bi-EDF of length 2.15 m is incorporated as both the Raman and Bi-EDF gain medium. Using a Brillouin pump with a wavelength at the maximum Raman gain but 2 nm lower than the Bi-EDFA free-running wavelength region, an optical frequency comb having 55 Brillouin Stokes lines is generated. The peak value of the Raman gain is about 6 × 10−13 m W−1 at the wavelength downshifted in frequency by about 14.2 THz (473 cm−1). This experiment suggests that by using a Bi-EDF instead of an EDF in a conventional EDFA, higher amplification can be obtained when the resulted Raman gain overlaps with the intense erbium gain prepared in this fiber.

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.

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.

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.

Wide-Band Bismuth-Based Erbium-Doped Fiber Amplifier With a Flat-Gain Characteristic

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> In this paper, a bismuth-based erbium-doped fiber amplifier (Bi-EDFA) that operates in both the C- and L-band wavelength regions is demonstrated. The system employs two pieces of bismuth-based erbium-doped fiber (Bi-EDF) as the gain medium with a midway broadband fiber Bragg grating (FBG). The FBG functions to prevent the gain saturation at the C-band region, flatten the overall gain spectrum, and reduce the noise figure, particularly for the C-band. At an input signal power of <formula formulatype="inline"><tex Notation="TeX">$-$</tex></formula>30 dBm and a pump power of 150 mW for both pumps, a flat gain of around 29 dB is obtained with a gain variation of <formula formulatype="inline"><tex Notation="TeX"> $\pm$</tex></formula>3.5 dB within the wavelength region from 1525 to 1615 nm using a backward-pumping scheme. At an input power of 0 dBm, the gain varies from 10 to 13 dB within the wavelength range from 1530 to 1620 nm, while the corresponding noise figure varies from 9.5 to 14 dB over this wavelength range. </para>