This question will shortly celebrate I believe 40 years old birthday :) There are heap of the paublications (peak was in about 1990). I have been working in telecom company in the USA and can tell you that from the point of view of power budget the solitons are not very attractive carrier inspite of their relative robustness to the noise and other perturbations. They could be interesting for ultra long, but not high capacity links. If you want more information, send me an e-mail, we can organize skype chat some time.

Best wishes and good luck!

Soliton pulse is actually a pulse shape used in Optical communication system and has several parameters to trade off between bandwidth and Inter symbol interference effects. because of smooth variation, this type of pulse shaping that nonlinear effects can affect bandwidth and loss for the signal modulated this kind of pulse shape. however attenuation always affect the signal should be accounted for the link budget.

Dr Mahboobi is quite correct in his definition of the conditions necessary for soliton formation. However, I believe that there is a 'cognitive stance' that we may adopt that is more intuitive/helpful with respect to the approach that might suggest itself when asking a question such as this.

Independent of the medium, complex waves attenuate partly because waves of different frequency travel at different rates in the particular medium. Given this situation there is no necessary relationship between the medium and its structure and the complex wave form. Solitons are different - there is a necessary relationship between the structure of the medium and the possibility of soliton formation. Solitons are not comprised of frequency components in the normal sense - this is partly the reason why they are so robust. Solitons are unique non-linear solutions to a set of boundary conditions implicit in the medium and its structure.

So, part of the utilitiy of using solitons to convey information is that the solitonic carrier of information can be selected as the best solution to the problem of sending a non-dissipate wave along a medium of that particular structure.

@Diva , Solitonian pulse are nothing more than a gaussian pylse shape that has decay frequency component in time and frequency domain. hence this feature help to reduce the bandwidth in place of more ISI in a well-defined way.

I got alittle confused by your statement :

"Solitons are not comprised of frequency components in the normal sense - this is partly the reason why they are so robust. Solitons are unique non-linear solutions to a set of boundary conditions implicit in the medium and its structure."

what nonlinear solution to the boundary condition are you exactly pointing out ?

let us be more clear and bring up a mathematically closed form slitoniam wave to discuss the relation of the pulse shape to the mentioned boundary conditions.

Please note this post is not challenge your statement, I actually became curious to know how we can design a (possibly optimized) Solitonian pulse shape for a specific graded index Fiber or diffracting optical lens.

does it actually result in a constraint optimization problem based on the fiber boundary structure ?

Dear Dr Mahboobi,

My comments are based more on an intuitve understanding - I am not a mathematician. It may well be that my comments are not quite accurate - it was simply a suggestion.

No offence intended.

If you are interested in the question as to why I adopt such a stance?, you may like to look at my own research - you may find that it offers a differing perspective.

Many thanks

Chris

Davia, C.J (June 2006), "Life, Catalysis and Excitable Media: A Dynamic Systems Approach to Metabolism and Cognition", in Tuszynski, J.A, The Emerging Physics of Consciousness (The Frontiers Collection), Springer, pp. 255–292, ISBN 978-3540238904

your answer was quite True, i was actually surprised by your answered. so please don't take my post as a offensive question.

This question will shortly celebrate I believe 40 years old birthday :) There are heap of the paublications (peak was in about 1990). I have been working in telecom company in the USA and can tell you that from the point of view of power budget the solitons are not very attractive carrier inspite of their relative robustness to the noise and other perturbations. They could be interesting for ultra long, but not high capacity links. If you want more information, send me an e-mail, we can organize skype chat some time.

Best wishes and good luck!

To return to the original question of Mr Gokul Baby Alex, the main constrain would be the cost. It is possible to create an optical soliton communication system that would have been of a greater bandwidth capability than the ones already established. Attenuation will always be one issue, but we could use amplifiers as usual. The main problem is that the current optical networks would have to be upgraded and probably redesigned. For example, in order to utilize optical solitons to their fullest some parts of the fiber lines would have to be replaced by specifically designed DCFs (dispersion compensation fibers), while the placement of the amplifiers would have to change.

All the necessary changes are very costly and it seems that the extra bandwidth that could have been gained is not considered a priority at the moment.

Thank you all for the answers. These thoughts provoke some supplementary questions in my mind. Please correct if any of my understanding is misplaced.

@Behrad Mahboobi, what is the underlying reason for trade off between bandwidth and inter symbol interference. Using some special spacial / temporal designs can be work around this trade off?

@Christopher Davia, really appreciate your 'cognitive stance' !. Can you please elaborate on how '. Solitons are different - there is a necessary relationship between the structure of the medium and the possibility of soliton formation' can be measured / predicated or conditioned to our needs!

@A. Chipouline, Thanks for sharing the history of interest in Soliton communication systems. I will contact you soon to know further!

@Nikolaos Moshonas, Thanks for taking a note of network economics associated with this idea. If replacing the existing fiber optic infrastructure is the challenge, can this be used for a next generation terabit network which requires high capacity and long distance carrier.

Dr Alex,

As you know, the first soliton observed was in a canal - with a regular structure - a repeating pattern. This strongly suggests a relationship between soliton formation and structure of the medium especially when we consider that for each depth of water only one solution is permitted.

As I understand it, you cannot do a fourier transform on a soliton. This seems to show it is not a complex wave as it is normally understood.

My work involves the catalytic action of solitons in biological systems. My findings strongly suggest that the robustness of the soliton in biological systems stems from the fact that the soliton embodies information about the boundary conditions of the medium. In biological systems the soliton is not only used to transfer energy - it also seems to be the principle conveyor of information! Thus, in biological systems - bioenergetics = bioinformatics!

Thus, to understand how the heart, for example, is so robust, it transpires that the action potential that moves through the heart is a solution to a set of boundary conditions determined by the heart itself. In the developing heart, evolution has utilized the roubustness of the soliton by closely linking development of the heart (growing phase) with the action potential - the action potential shapes the heart and the heart shapes the action potential - see attached file above.

This is why I think that it is important to think of solitons as energy/information carriers.

I think that a new approach to designing communication systems using solitons may require a different type of thinking. We may be able to take a leaf out of the book of the 'active optics' guys.

Much expense is often involved with a new technology. I imagine that you may be considering how to make extremely 'pure' fibre optics. It may be possible, in the future, to design technologies where the imperfections in the finished product are an accepted part of the process. The real work is done afterwards by some process where, the particular solitonic solution (involving the imperfections within the system) for 'a particular part of the communication system are uniquely established - the particular non-linear solition for that particular problem.

I hope that this helps.

Chris

the procedure of designing pulse shape for dispersive fiber is very well described in the book "optical fiber communication" by Gred Kaiser. the design procedure start with obtaining the Fourier transform of the Soliton pulse shape and then make a connection between the bandwidth and interference by analyzing this pulse in frequency and time domain. the details are very well describe in that book.

Yes, solitons can be used in a next generation telecommunication network, although practical efforts have been ceased ten years now.

I see confusion between "attenuation" and "dispersion" in this thread. Solitons are interesting because of the dispersion compensation, which allows very narrow pulse and high single frequency bandwidth. However, they are still suffering attenuation by absorption and scattering centers, and need repeaters for amplification along the fiber.

In addition, the narrow bandwidth on which soliton can take place may prevent large band wavelength multiplexing, reducing the overall system capacity.

Most so called "soliton systems" are just short pulse systems in which the nonlinear induced phase is partly balanced by dispersion. The reason is that a perfect balance cannot be achieved over a length in which there is any significant loss. So a true Soliton system of a few km length is viable, but not longer, (unless on tapers the dispersion along the length or has continuously distributed amplification). The first few km of along system can perform this balance but the rest not.

Neither true or pseudo soliton systems are of any interest in telecomms now as the poor spectral efficiency makes them very inferior to the modern coherent multi-phase multi-level transmission systems. But they were fun for a time. We build and publicly demonstrated a 100G one in 2000 in Geneva.

In principle, one can imagine à transatlantic soliton propagation in an optical fiber. Soliton could limit the number of repeaters on long distance communication. The drawback is that it only works at a unique light frequency (colour) and therefore severely limits the bandwidth of the system. AT&T did quit on soliton propagation at the time of development of erbium-doped fiber amplification and multy-wavelength multyplexing [1].

Soliton based communication could still find niche applications in situations where repeaters are not acceptable.

https://en.wikipedia.org/wiki/Optical_amplifier#Doped_fiber_amplifiers

Yes 1 Study of solitons for telecom still an intersting field.

Present microstructured fibres thrown ebough potential.

Solitons basically formed with the balancing force of dispersion and self phase modulation.

In this we have spatial as well as temporal type solitons. The later is preferred for telecom with less distortion in pulse.

Commercial implementation has many challenges - existing fibres mostly single mode conventional fibres and system speeds increasing beyond 100GHZ with DWDM etc.

I will be able mail you more such intersting,but challenging observations

regards

g kumar

Maybe it's too late to answer, but nevertheless... The soliton communication concept has now re-emerged into the concept of communications based on the nonlinear Fourier transform, where the solitons are rather treated as nonlinear modes and used together with the non-soliton radiation, see some relatively recent advances in the review (the filed evolves quickly and that review is already a bit outdated):

Nonlinear Fourier transform for optical data processing and transmission: advances and perspectives

SK Turitsyn, JE Prilepsky, ST Le, S Wahls, LL Frumin, M Kamalian, SA Derevyanko

Optica 4 (3), 307-322 (2017),

and the good paper depicting the general concept:

Nonlinear signal multiplexing for communication beyond the Kerr nonlinearity limit

ST Le, V Aref, H Buelow

Nature Photonics 11 (9), 570 (2017).