EDFA/Raman hybrid amplifier gain

[Dennis Jacq]

Hi Guys,
I am currently simulating EDFA/Raman amplifier in terms of output gain base on the journal “Gain Flattening of EDFA using Hybrid EDFA/Raman Amplifier with Reduced Channel Spacing”. My problem is the resulting gain that I get from the hybrid amplifier seems like its not affected by the Raman amplifier at all. I have attached sample of my result and simulation from Optisys. I am using a 5m EDFS and 25 km RFA. Is it because the pump power or connection?

[Dennis Jacq]

I get the result I wanted for EDFA/Raman hybrid. The problem is when I observe the individual gain for EDFA and Raman alone, i get a high noise figure for Raman and the total gain for the system are lower than the EDFA gain when observed alone

[Hamza Ali Abbas Khan]

Hi Dennis

I have attached a pdf file and an osd file regarding gain flattering. You may go through the pdf.

Hope this is helpful to you.
Thanks

[Dennis Jacq]

Thank you very much sir 🙂

[umer ashraf wani]

https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=9&cad=rja&uact=8&ved=0ahUKEwjPicOd4ufMAhWGK6YKHebMDPoQFghYMAg&url=http%3A%2F%2Fphotonics.pl%2FPLP%2Findex.php%2Fletters%2Farticle%2Fdownload%2F3-58%2F196&usg=AFQjCNHDe5ynm6bbESGIMyq7aLAAh8jk2Ahttps://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=8&cad=rja&uact=8&ved=0ahUKEwjPicOd4ufMAhWGK6YKHebMDPoQFghSMAc&url=https%3A%2F%2Fwww.ijedr.org%2Fpapers%2FIJEDR1503085.pdf&usg=AFQjCNEyHpFl6corxmSg1MohfzHptIzXqA
https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwjPicOd4ufMAhWGK6YKHebMDPoQFggcMAA&url=http%3A%2F%2Fopt.zju.edu.cn%2Feclass%2Fattachments%2F2011-11%2F01-1321946101-71122.pdf&usg=AFQjCNH48TEmpLbhjQhWW4cnBAItd6Da8w
https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&uact=8&ved=0ahUKEwjPicOd4ufMAhWGK6YKHebMDPoQFggiMAE&url=https%3A%2F%2Fwww.finisar.com%2Foptical-amplifiers%2Ffoa-r9300th-hbr3c-aa001&usg=AFQjCNHXFxgrA-cpchAk0sNurmWdVKAl1g
https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&cad=rja&uact=8&ved=0ahUKEwjPicOd4ufMAhWGK6YKHebMDPoQFggwMAM&url=http%3A%2F%2Fwww.sciencedirect.com%2Fscience%2Farticle%2Fpii%2FS0030401815004058&usg=AFQjCNEtwr1uc7uSwqwMZtPJe-4qjLIfTQ
https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=5&cad=rja&uact=8&ved=0ahUKEwjPicOd4ufMAhWGK6YKHebMDPoQFgg4MAQ&url=https%3A%2F%2Fwww.osapublishing.org%2Fjosk%2Fviewmedia.cfm%3Furi%3Djosk-14-4-342%26seq%3D0&usg=AFQjCNEwwir8AiJufb9Gt0LGYldXvAwgmQ
https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=6&cad=rja&uact=8&ved=0ahUKEwjPicOd4ufMAhWGK6YKHebMDPoQFghAMAU&url=http%3A%2F%2Fwww.scielo.br%2Fpdf%2Fjmoea%2Fv9n2%2Fv9n2a04.pdf&usg=AFQjCNHb_LTHwldQ7EoFkiwLxjc4QnBNyA

[Karan Ahuja]

Hi.
I want to mention that the Hybrid module consists of a counter-propagating Raman pump unit and a variable gain (VG) EDFA. These two elements are integrated to provide exceptionally low noise figure and excellent gain flatness – two imperative parameters for ultra-long haul systems. The module can support up to 3 Raman/EDFA pumps in various configurations.

Since the module’s first stage is a Raman pre-amplifier which has a negative effective noise figure, the overall combination of the Raman pre-amplifier and VG EDFA has a very low effective noise figure. This allows the link reach to be extended 3 to 4 times, in comparison to a system based on traditional EDFAs. The Hybrid control circuitry operates in advanced AGC mode, in which the actual Raman gain is automatically measured and then complemented using the EDFA gain. The required total gain is therefore constantly maintained. This fast AGC control circuitry also provides excellent transient suppression, allowing the amplifier to keep the gain constant also in cases where there are fast and large changes in the input power (regardless of ASE produced by the Raman pump).

The module also incorporates laser safety mechanisms, ensuring that both the Hybrid Raman-EDFA module itself and the network in which it is installed can be classified as Class 1M products with respect to laser safety.

You may refer to this link for further query https://www.finisar.com/optical-amplifiers/foa-r9300th-hbr3c-aa001

[Karan Ahuja]

I am also attaching link of a paper which may be very useful to you. It It is based on the amplifier spectral equalization by adjusting the flexible gain profile of a multi-pump Raman amplification stage to compensate the Erbium-doped stage gain variation within the C-band. In order to increase the pump power efficiency, the Erbium-doped fiber section recycles the residual Raman pump. Three different cases considering, respectively, one, two, and three pumps are analyzed to demonstrate the effectiveness of the proposed technique. The characterization of the Raman+EDFA hybrid amplifier has been performed in terms of global gain, ripple, and noise figure. The proposed optimization method for the Raman pump sets allows ripple figures to be reduced by half of their original values in single pumped configurations. Our results also suggest that two pump lasers is the best configuration when the maximum gain, minimum ripple, and pump power efficiency are simultaneously considered.
http://www.scielo.br/pdf/jmoea/v9n2/v9n2a04.pdf

The results results demonstrate that this kind of hybrid amplifier, with the properly chosen pump wavelengths and powers, enables the design of broadband devices with enhanced power conversion efficiency. Optimal EDF length studies, considering specific input signal power levels, could lead to even better results as the EDFA gain saturation condition could be avoided.
Hope it helps.
Regards

[Author]

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