Optical wireless communication ideas

[ElectroFractal]

Hello PF!

I have developed a recent interest into electro-optics used in communication systems. Specifically speaking, I am mostly interested into Optical wireless communications and their applications, for terrestrial to satellite communication. I am considering to do a research project for my bachelor studies, if I can manage to do it.

I would like to ask for some possible ideas, as I failed to find by myself, as a research topic for a project. It shouldn't be oriented to engineering exclusively, some theory of physics shouldn't be lacking. It could contain some simulations and modelling (in MATLAB, for example), but hardware implementations aren't the first thing I'd do (so far).

According to research of recent date, it is a very promising technology that could solve many problems, so I would like to learn more about it, ideally do some specific project for which I am looking for ideas.
I am not constrained with time, so time-wise everything is acceptable, and I should mention that I am studying Electrical engineering.

Thanks for every reply in advance. Every help is welcome!

 

[DaveE]

I think much of your work will end up being in the absorption and scattering of light in the atmosphere. Will your comm link work through rain and clouds?

 

[davenn]

Summary:: I need some ideas to do a project on a specific topic for Optical wireless communications discussed from aspects of physics and engineering.

I am not constrained with time, so time-wise everything is acceptable, and I should mention that I am studying Electrical engineering.

I think much of your work will end up being in the absorption and scattering of light in the atmosphere. Will your comm link work through rain and clouds?

not likely

which is why microwave radio links is used

 

[DaveE]

I am not constrained with time

You may be the only person on the planet who can say that, LOL.

Others have already done a bunch of work in this area. I worked for several years on an aircraft to submarine laser comm link (SLCAIR), which worked OK as a DARPA demonstration project. You would be more interested in a program called SLCSAT, a satellite to submarine system. In both cases the advantage is that light goes through salt water better than radio waves, lasers have much greater bandwidth than VLF radio, and lasers are more secure, since they only go where you point them.

Anyway, I digress. You should start your project with a literature search to find out what others already worked out.

 

[sophiecentaur]

Summary:: I need some ideas to do a project on a specific topic for Optical wireless communications discussed from aspects of physics and engineering.

Hello PF!
Thanks for every reply in advance. Every help is welcome!

This is a very open ended request. You would get a much more useful set of responses if you had some sort of target of interest. What level do you want to work at? This is essentially an Engineering topic as it encompasses a huge number of different aspects of Physics, Comms Theory, Device Technology etc. etc. plus overall Systems Design.

There are contradictions in what you have written so far: For instance, you have said "not likely" to a question about rain and cloud attenuation. That is not consistent with investigating Satellite Communications systems - so which is it to be?

I have to assume that you have read something about the topic and have found at least one or two parts of particular interest. I see you are attracted to a Simulation but merely being able to avoid the graft of building equipment or doing theoretical stuff will not necessarily allow you to construct a useful and convincing study. You still have to know what are the relevant 'knobs to twiddle' in a Simulation.

 

[Anand Sivaram]

There have been many prior works and attempts in this regard. Please do take a look at technologies like RONJA, LiFi etc.
https://en.wikipedia.org/wiki/RONJA
https://en.wikipedia.org/wiki/Li-Fi
https://en.wikipedia.org/wiki/Free-space_optical_communication

The useful range of free-space optical communication is always limited to around 2 km in the visible spectrum (400nm to 700nm) because of rain, fog, snow, dust, scattering Line of Sight requirement etc. So, communicating with a Satellite looks very difficult.

 

[DaveE]

Now this: https://www.wired.com/story/physicists-clear-the-air-with-a-sweet-frickin-laser-beam/

 

[sophiecentaur]

There have been many prior works and attempts in this regard. Please do take a look at technologies like RONJA, LiFi etc.
https://en.wikipedia.org/wiki/RONJA
https://en.wikipedia.org/wiki/Li-Fi
https://en.wikipedia.org/wiki/Free-space_optical_communication

The useful range of free-space optical communication is always limited to around 2 km in the visible spectrum (400nm to 700nm) because of rain, fog, snow, dust, scattering Line of Sight requirement etc. So, communicating with a Satellite looks very difficult.

When the frequency allocations were bid for by the startup satellite broadcasters, the options were all studied in detail. No one went for optical uplinks or downlinks - for very good reasons. Same goes for terrestrial links. Optical frequencies are great for fibre comms and also would be well suited to space comms, all other things being equal.

 

[f95toli]

What about free space QKD? Here lasers ARE used for terrestrial-to-satellite communication.
It is currently a hot topic and it is growing very quickly, the first experimental demonstration was done by the Chinese (who has a satellite specifically made for this) quite recently.
Of course this would need to be theoretical project, but I suspect you could do a fair amount of interesting modelling.

 

[berkeman]

What about free space QKD? Here lasers ARE used for terrestrial-to-satellite communication.
It is currently a hot topic and it is growing very quickly,

Interesting, thanks for the info. Here is a paper that I found with a quick Google search:

https://www.nature.com/articles/nphoton.2017.116

 

[sophiecentaur]

@f95toli QKD. I was thinking in terms of a continuously available channel but using patches of good viz suits some applications. (I was in broadcasting so hence my reaction)