DCF

[Heitor Galvao]

Good day, please can you tell me how to configure references the parameters of a DCF according to this network in annex

[Heitor Galvao]

Want to better understand the parameters of the DCF, can someone help?

[Heitor Galvao]

A brief explanation of SMF and DCF, someone has good books about SMF and DCF?

[Heitor Galvao]

Articles also please

[Heitor Galvao]

I didn’t find any topic here on the forum about SMF, so about DCF

[Damian Marek]

An easy way to do it is to match the lengths of the fibers and then set the dispersion to the opposite (negative) of the transmission link. The amount of broadening a pulse experiences is a linear expression involving length and also D. So you could half the length and double the dispersion parameter. If you want to include third order dispersion and multiple frequencies (dispersion is a function of wavelength) it can be a lot more complicated.

[Heitor Galvao]

What are the correct values of variables such as DCF’s area effectively?

[Damian Marek]

The effective area parameter is used in our simulation to model nonlinear effects (not dispersion), so you should use the effective area that is attributed to the fiber that you are simulating. A common value and the default we use is 80 um^2.

In a real life scenario a DCF might have a different value since the waveguide might have a different structure (smaller or bigger). You can use OptiFiber to calculate its effective area or you can use the link below to read about a similar topic. I made a matlab/Optisystem file that demonstrates how to calculate the effective area from a spatial distribution.

System Power Penalty and Link Margin

Regards

[Heitor Galvao]

Thanks Damian, I’ll check

[Josh Weber]

Hello. This is regarding post #14698 above.

Damian, you mentioned that “The effective area parameter is used in our simulation to model nonlinear effects (not dispersion),…”. Is there an alternative way to take effective area into account to model modal dispersion in the simulation?

Thanks.

[Damian Marek]

Yes, but you would need to use a different component. The Optical Fiber component models a singlemode fiber.

You can try either the Linear Multimode Fiber or one of the spatial models in the Multimode Library/Optical Fibers folder.

The Linear Multimode Fiber allows you to explicitly state the modal delay, whereas the two spatial components will calculate the modal dispersion from the actual modes that exist for the described index of refraction distribution. If you get confused by the difference just take a look at the associated Help for each.

Cheers!

[Josh Weber]

Excellent! Thank you, Damian.

[Ravil]

I would also recommend to look at G.652-G.655 recommendations of ITU-T about SMF and DCF/NZDSF for general knowledge…

[Heitor Galvao]

Ravil you have them in your files?

[Alessandro Festa]

Heitor please note that usually DCF has smaller area than standard G652, this has an impact if its input power is high…if ou want more information I can check if I have something in my folders.

[Heitor Galvao]

Please check your files
my compliments

[Alessandro Festa]

If you give me your email I can send you a .txt file with Area vs wavelength

[Heitor Galvao]

follow email: heitorbrunogalvao@gmail.com

[Ravil]

Hi Heitor, sorry for late reply. The files of ITU-T recom. I mentioned before are attached. You should be able to find info about DCF in chapter 3 of G.655 file.

[Heitor Galvao]

Ravil thank you!!

[Ravil]

The other attachment is here…

[Heitor Galvao]

Again Ravil thank you!!

[Ravil]

Just for your information, if you go to ITU-T website you can even find this recom. even in your language if you like.

[Heitor Galvao]

I prefer it to be in English so I can train, thanks for always be helpful and excellent tips Ravil

[Salwa Mostafa]

Hi Heitor Galvao

Where is the DCF component in optiwave library ?

Thanks in advance

[Heitor Galvao]

The optisystem offers the block “optical fiber” you will move on his properties to make it a DCF or SMF, follows where you can find him:
Default/Optical Fibers Library/Optical Fiber
my compliments

[Ravil]

ok, I see. You are welcome!

[Ravil]

For engineering approach, I would recommend you “Optoelectronics and Photonics: Principles and Practices” S. O. Kasap. It’s easy to read and not too big in size. Unfortunately, I don’t have it in e-version.

[Heitor Galvao]

Thanks Ravil by indication, please look at the private message that I sent
my compliments

[vignes]

dear heitor,

i just saw ur post regarding dcf, i sent one book to ur private id , refer that book and also make some clarification if need

[Ravil]

Hi Vignes, what book do you recommend? (just curious…)

[Heitor Galvao]

Tell your email that I submit the material

[vignes]

dear ravil,

dcf by siddarth ramachadran fiber based dispersion

[Heitor Galvao]

Many thanks Vignes excellent book
my compliments

[Dr Rk Sethi]

It has been observed that dispersion of a standard single mode fiber (SMF)is lowest at 1300 nm, whereas it has minimum attenuation at 1550 nm. But at 1500 nm wave length the dispersion is higher. The problem of dispersion can be compensated by inserting an element that imposes dispersion on the optical signal that is opposite (negative) to that imposed by optical fiber. Most common is the use of the dispersion compensation fiber (DCF), with strong negative dispersion, placed at regular intervals along the link It can actually reverse the effects of dispersion suffered by 1550 nm signals that traverse standard single-mode fiber. But it has the disadvantage of high cost, physical size, signal delay and lack of adaptability. The attenuation of the DCF requires additional optical amplifiers, which introduce additional optical noise.

[Ravil]

Hi Rk Sethi,

Do you have an idea how often DCFs are used for dispersion compensation in the way you described above? In other words, is it still common application of DCF now-days when DBGs and electronic compensation is widely used?

[Dr Rk Sethi]

The physical characteristics of dispersion & the resulting signal distortion have been studied extensively and different techniques for the dispersion compensation have been reported. There are several different methods that can be used to compensate for dispersion, including DCF, chirped Bragg gratings, all-pass optical filters and optical phase conjugation. These methods restore the signal such that it can be received in a normal receiver.
An alternative method is to detect the dispersed signal and perform the dispersion compensation electrically.
Fiber Bragg grating (FBG), which is widely used in wavelength filtering and smart sensing devices has become a very important technique for making tunable dispersion compensators. Ken-ichi Kitayama et al. in have investigated both theoretically and experimentally the dispersion effect of FBG used as the filter on DWDM millimeter-wave optical signal transmissions.

[Ravil]

Thank you very much for your detailed answer, Rk Sethi!

Just wanted to clarify one moment:
what is the main advantage of DCF dispersion compensation in comparison with other techniques?

[alistu]

The main advantage?Just being “straightforward”!
Using DCF, you just need to calculate fiber dispersion and use DCF to compensate the cumulative amount of dispersion caused by the line.

[Ravil]

Thanks for your answer Alistu, I was trying to find out the advantages of DCF vs DBG or electronic compensation (this method became very popular lately). As far as I found out from other sources:
1. DBG can’t cover such a wide range as DCF
2. Electronic compensation makes receiver more complicated and can be too costy.
Please, add/correct me if I’m wrong.

[Dr Rk Sethi]

Welcome Ravil

[Heitor Galvao]

complementing: https://optiwave.com/category/products/system-and-amplifier-design/optisystem/optisystem-applications/dispersion-management/

[Ravil]

Rk Sethi, Thanks for your detailed explanation again!

[Author]

Posts