Why isn't Fiber Optic an Option for Monitor Displays or Graphics Cards?

Optical cables are not as good as HDMI in hi resolution audio. Blu-ray: Dolby TrueHD and DTS HD Master Audio formats can not be transmitted by optical.

"Audio formats can not be transmitted by optical."

There must be some exceptions to that. I have a sound bar mounted above my TV that connects to the TV via optical cable.

Um, you clipped at the wrong point for your quote, that's why it didn't make sense to you.

"DTS HD Master Audio formats can not be transmitted by optical."

Lower fidelity audio signals CAN be send over Optical, but the higher fidelity signals need more bandwidth than fiber can provide.

This technical paper by Dolby seems to refute that.

What?? Really? Wrong.

Different connections are used with different formats and have different capabilities....some manufacturers have agreements with certain format providers...

Here's a list of format and connection types with their capabilities...

http://www.ramelectronics.net/howto-av.aspx

GA.

There's lots of complexity in taking a relatively low bandwidth signal, (that are transmitted over the short distances of consumer electronics usage) and converting the signal to photons, sending them down a fiber, and then reconverting back to electric signals. Copper connectors and harness build, is simple compared to doing this reliably and cheaply using plastic or glass fiber methods.

Being in the fiber optic modem industry (R&D and manufacture) I would say that the cost is the largest deterrent. The real question to ask is "Why would one use fiber optic transmission?" of anything. Distance, security and noise immunity are the key reasons to use fiber.

Transmitting any signal over a long distance is susceptible to signal degradation and injected noise. Fiber would be ideal as it is immune to external noise and signal loss over distance is very small. A said monitor is no more than a metre or two away from the PC. It would be pointless to add (as someone mentioned) extra conversions for the sake of doing so.

Security is also a big issue as one cannot simply "tap" into a fiber over any distance. Again, since the monitor is only a short distance, securing this link would be pointless.

I will challenge anyone to say that any other format (HDMI etc) is better than fiber - as someone eluded. We design and produce many industrial modems that transfer data through HDMI, SDI, DVI, HD, audio, data, analgue video etc. The choice really is "horses for courses".

An example of one of our products in use is a PC monitor at a railway station. The PC that runs the platform displays is typically >100m away. Using copper/coax would render the screen "noisy" and also EMI from passing trains could produce distorted images. Our underground railway stations employs our products to head up a crystal clear display for the commuters free from "noisy" screens.

"I will challenge anyone to say that any other format (HDMI etc) is better than fiber - as someone eluded."

Such an open-ended statement is folly to anyone who thinks things through. It's the equivalent of saying one format is 'best' without giving the conditions tested.

Let us look at a simple example, from the realm of Fantasy games. You typically have four hero types, or 'classes,' the Fighter, the Thief, the Wizard, and the Cleric. Which is the best?

The Fighter has the strongest arm, and can do the most damage when going toe-to toe with the marauding hordes, but can he dispatch the foes standing back and firing at him with longbows? Sadly, not.

The Thief is expert in stealth and camoflaguge, able to sneak through the shadows and underbrush without a sound, and can dispatch almost any single foe with a well aimed dagger to an unprotected back, but if he is spotted before he can strike, he is all but defenseless against retaliation.

The Wizard can call on arcane forces to smite foes from great distances, but when the battle becomes close, he is as helpless as a member of the Chess Club surrounded by angry members of the Football/Rugby team.

The Cleric has some battle skills, just enough to keep himself from being a liability in combat, however, his true skills come in being the Team Medic, healing the injuries of the others so they can fight on when otherwise they would have fallen.

Each is the 'best' at what they do, but no-one is the 'best' at everything. It is the same with the transmission formats, no single one is 'best' for every situation, so each situation requires a different format.

Some of the reasons above are thru, others are just a guess in the wild.

Optical fiber cables are not more expensive than copper, in fact they are cheaper.

Putting a plug on them is the tricky part in the whole cost picture. (requires specialised equipment and trained operators)

With POF some of the issues are omitted and solved. (Plastic Optical Fiber)

Still remains indeed the transfer from the electric signal in the computer to the optical signal: this part is indeed an overkill.

The missing speed requirement is indeed another factor.

The whole problem is latency: it is difficult to change a functional system.

Most computers have HDMI and DVI exits, and most projectors/monitors also, still we see those stupid, problematic VGA cables being used. (even using HDMI to VGA converters)

But it will change: there is big international effort to do optical communication on the main board to overcome actual bottlenecks that starts to limit computer to perform faster. higher definition screens will require higher speeds also thus requiring higher bandwidth cables.

If the IC's intercommunicate optically in the near future, going back to electricity would be an avoidable cost.

My proposal is to create a new inter device connection system based on Optical communication: it could replace all other cabling options.

Optical USB but even more versatile/universal: put it between two computers and they could build a network, from a computer to a screen and the screen tells the computer it is a screen so the specific sockets are installed to couple that port to the graphics processor (or even move the graphics processor to the screen and use X11 style graphical engines)

In fact all devices are computers so they can tell each other what they can do for each other: external hard drive, printer, screen, keyboard/mouse (please do this wireless) endless list.

Fiber cables have the following advantages:

1) Very high BW (in other words, high data rate)

2) Low attenuation (signal transfer on higher distances)

3) No electromagnetic (EM) radiation / infinite EM immunity

4) Communication safety (difficult interception of data)

5) General safety issues (e.g. no danger of fire in areas with flammable materials)

6) No crosstalk between adcacent optical lines

They, also, have the following disadvantages:

1) More expensive compared to the copper cables

2) Higher complexity (electronic circuits are included in order to convert electrical signals to optical signals and vice versa) reducing the reliability compared to the copper cables.

So, as you can see, for lower bandwidths (like -e.g.- Hi-Fi audio signals or relatively low data rate of your computer) it's much cheapper and simpler to use copper cables. As an example, even for the Gigabit Ethernet connections (1Gbps) we usually use twisted pair copper cables for relatively low distances (however fiber cables are also used mainly for high distances). For higher data rates though (like 10Gbps or 100Gbps) only fiber cables are used due to the very high bandwidth of these signals. That's why, in general, copper cables are used in most commercial and home applications. Fiber cables are mainly used in the large backbone networks (where huge amounts of data are transfered in very high speeds) or in other special cases due to their advantages (already mentioned).

I have to counter claim 5: due the high concentration of energy (light is energy) optical communication cables are not assumed to be harmless in classified area's and need to be treated as all other spark sources.

Fiber optic cables are NOT a source of sparks.

Fiber optic cables may cause flammable cloth or paper to ignite because of the intense light beam, usually associated with fiber optic illumination systems used in hospital surgery rooms.

SSorry, I got lost in translation: they are indeed not a source of sparks but they need to be treated as spark sources are treated.

Regards

Hi Gwen. The "danger" of ignition of flammable materials is an actual danger only in the cases of very high power laser beams. Even for lighting purposes there is not such a danger (I'm talking about the usual flammable materials and the usual light intensities. Have you ever seen -e.g.- the ignition of such material because of a spotlight???) Moreover, here we are talking about fiber cables which transfer data or other signals. In such cables the power of light is just a few milliwatts.

I have to counter you here: it is not the total power but the power density which is important for ATEX.

I have been in a project where I had to make sure every connection had to be outside the classified area or encapsulated in an EXd enclosure. And we were only measuring the temperature of a pipeline, laser power was only 0.7 mW.

But this 0.7mW is contained in a 9µ zone in a FO cable

I was of the same idea until I was doing an intallation and got stopped: no ATEX certificate = no connections in the field.

It is true that the cable itself is safer, no risk of overheating due short circuit or so.

But it is the end of the cable, the connection where the issues can arise.

Some flammable products auto ignite at very low temperatures, that is why there are temperature classes.

In your home application they are safe. Enter the (petro)chemical industry and they don't "assume" it is safe, Enegy is enegry and heat can come from everywhere.

I agree about the "end of the cable" mainly because there is electronic circuitry over there (conversion from optical signals to electrical signals and vice versa). And several problems (shortcircuits, sparks , overheating) may arise in this circuitry. So, it's obvious that the "ends of the cable" (and the associated circuitry) must be located outside the dangerous area. My question is: Is there any safety problem if just the fiber cable (i.e. not its edges) is located inside a dangerous area??? Even if the cable is accidentally broken and a (e.g.) laser beam of a few mW is emitted from its broken edge, can this beam ignite a flammable material??? What kind of flammable material may be ignited by such a low light energy (paper, plastic, oil, gasoline)??? Do you have any info on that issue???

Please read #17 again.

The cost is too high.

The direction we are currently heading is to RF signal transmission that utilize conductor free components which do not use fiber or copper.

No messy tangle of wires/cables. YEAH!

Noise impingement and sound quality? Sometimes YUK!