Gain flattening by long period gratings in erbium doped fibers (original) (raw)
Related papers
Two Methods for Synthesizing the Long Period Fiber Gratings with the Inverted Erbium Gain Spectrum
Japanese Journal of Applied Physics, 1999
We propose and compare two new methods for synthesizing piecewise-uniform long period fiber gratings. The proposed methods, which employ the optimization algorithm based on the lattice filter model, are used to design the equalizer which compensates for the nonflat gain characteristics of the erbium-doped fiber amplifiers (EDFA). We have obtained design parameters of piecewise-uniform long period fiber gratings which fit the inverted erbium gain spectrum of a commercially available EDFA over the entire 1525 nm–1570 nm range. We analyze the sensitivity of the two proposed methods with respect to the parameter variations.
Broad-band EDFA gain flattening by using an embedded long-period fiber grating filter
Optics Communications, 2007
An erbium-doped fiber amplifier (EDFA) gain flattening technique using an embedded long period grating (ELPG) is proposed. By bending the ELPG, due to different coupling strengths yielded from different bending curvatures, it can be used for both the static and dynamic gain flattening despite of the different pump currents of the EDFA. The experimental results demonstrate that the flattened gain region of 34 nm can be achieved within 1 dB ripple.
Experimental characterization of a dynamically gain-flattened erbium-doped fiber amplifier
IEEE Photonics Technology Letters, 2000
We have designed and experimentally characterized an erbium-doped fiber amplifier (EDFA) which possesses a wavelength-independent gain spectrum, independent of the operating level of the gain (dynamic gain flatness), and without requiring any gain-level-dependent control of any parameters. In the wavelength range 1542-1552 nm, the gain was flat to within the experimental uncertainties of f0.3 dB even as the gain level changed by 17 dB. The EDFA was based on a low-AI-content alumina-germanosiiicate EDF and a Mach-Zehnder filter. We believe that this type of EDFA, which has not been demonstrated before, can significantly simplify the design of amplified wavelength-division multiplexing (WDM) transmission systems and increase the robustness of long-distance WDM transmission.
2012 International Conference on Computer and Communication Engineering (ICCCE), 2012
A wide-band and flat gain Erbium-doped fiber amplifier (EDFA) is demonstrated using a gain media of high concentration Silica-based erbium doped fiber (EDF). The amplifier has two stages comprising a 1.5 m and 9 m long EDF optimized for C-band and L-band operations respectively, in a double-pass series configuration. The CFBG is used in both stages to allow a double propagation of signal and thus increases the attainable gain in both C-and L-band spectra. At an input signal power of-30 dBm, a flat gain of 22 dB is achieved with a gain variation of ±3 dB within a wide wavelength range from 1530 to 1600nm. The corresponding noise figure varies from 4 to 8 dB within this wavelength region.
EDFA gain flattening optimization with long period fiber gratings in WDM system
Journal of Optical Communications, 2021
This paper highlights a proposed optimized gain flatness technique for nonuniform gain spectrum of the erbium-doped fiber amplifier (EDFA) by introduction of long period fiber gratings (LPFG). In this analysis, EDFA gain spectrum has been evaluated between 1525 and 1600 nm with −20 dBm input signal power. Attenuation peaks of LPFG are optimized with a grating period of 240 µm and grating length of 30000 µm in the wavelength range of 1.1–1.8 μm, to compensate the peak gain of EDFA. Results have shown that EDFA peak gain of 35.94 dB is achieved at 1532.89 nm wavelength. This 35.94 dB peak gain is flattened up to 2.65 dB using long period fiber gratings. Also, less than ±0.3 dB gain flatness is achieved between 1528 and 1560 nm wavelength. The proposed less complex technique can be used to modify the grating parameters during fabrication in order to produce the loss peak at desired wavelength, which is efficient to flatten EDFA gain peak.
Design and fabrication of an intrinsically gain flattened Erbium doped fiber amplifier
Optics Communications, 2009
We report design and subsequent fabrication of an intrinsically gain flattened Erbiumdoped fiber amplifier (EDFA) based on a highly asymmetrical and concentric dual-core fiber, inner core of which was only partially doped. Phase-resonant optical coupling between the two cores was so tailored through optimization of its refractive index profile parameters that the longer wavelengths within the C-band experience relatively higher amplification compared to the shorter wavelengths thereby reducing the difference in the well-known tilt in the gains between the shorter and longer wavelength regions. The fabricated EDFA exhibited a median gain ≥ 28 dB (gain excursion below ± 2.2 dB within the C-band) when 16 simultaneous standard signal channels were launched by keeping the I/P level for each at -20 dBm/channel. Such EDFAs should be attractive for deployment in metro networks, where economics is a premium, because it would cut down the cost on gain flattening filter head.
Gain-clamped erbium-doped fiber amplifier using a single fiber Bragg grating
Microwave and Optical Technology Letters, 2001
A new design of an all-optical gain-clamped erbium-doped fiber amplifier is demonstrated. The amplifier is based on the con¨entional ring ca¨ity, where the gain is clamped at 21.84 dB¨ia optical feedback using a single fiber Bragg grating for an input signal power as high as y8 dBm. ᮊ
Long-period fiber-grating-based gain equalizers
Optics Letters, 1996
Long-period fiber gratings are used to flatten the gain spectrum of erbium-doped fiber amplifiers. A broadband amplifier with <0.2 -dB gain variation over 30 nm is presented. We also show that a chain of amplifiers can be equalized, leading to a bandwidth enhancement by a factor of 3.