Optical interconnects

Question

What are the challenges involved in using optical interconnects? As they are efficient than copper interconnects in many aspects like power consumption and data rates, what is preventing using from using optical interconnects?

Answer 1

In general, it requires energy to convert electrical signals to and from optical signals. However, depending on the type of optical fiber that you use, you can send that signal for much longer distances without losing the integrity of that signal.

One great advantage of using an optical link between devices is the electrical isolation that is afforded. For example, we use 1mm optical fiber and simple optical transmitters and receivers to provide signal transport and isolation for low-speed serial signals between devices that can be many thousands of volts apart from each other.

One supplier of low-cost 1mm plastic fiber and user-friendly optical transmitters and receivers is Industrial Fiber Optics.

Answer 2

Optical interconnects are absolutely the best but it really depends !! It purely is based on your application and its complexity. Clearly optical interconnects is a front runner when electromagnetic interference(EMI) is a constrain.

But you should some factor that prevents one from using optical interconnects:

1. Complex than analog
2. More room required
3. Bandwisth of signals
4. Cost
5. Cost

If you are talking about low frequency analog read outs travelling over few CM's i dont see a benefit of using optical interconnects and making it complex and really expensive.

Also i will prefer copper to carry my signal if it involves a lot of twist and bend as optical fibres are prone to bending losses.

I have had an scenario which involves analog readouts to be transfered few mm's at the cost of EMI. I didnt have room or budget for optical fibres and i had to manage with analog signals with good filtering techniques. Trust me it was much simpler and cheaper option.

Answer 3

Do you mean the optical interconnect in the Wikipedia sense? If that's the case here are some pro's and contra's:

Pro's of optics:

1. Higher bandwidth than copper.
2. Better security.
3. Insensitive to external electro-magnetic fields.

Contra's:

1. More expensive.
2. Much more difficult to install and maintain.
3. Require electro-opto-electric conversion when used for telecom.

This combination of advantages and disadvantages makes the choice relatively easy in most cases: if you want a simple, cost-efficient solution and do not need high bandwidth, use copper. If you want high-bandwidth, future-proof or very reliable or secure connection, optics is the way to go. There is actually almost no overlap.