Ever thought of using the FOXI chip set? might be the simplest
method....

>----------
>From:  Bob Fehrenbach[SMTP:bfehrenb@EXECPC.COM]
>Sent:  Thursday, March 20, 1997 6:04 PM
>To:    PICLIST@MITVMA.MIT.EDU
>Subject:       Re: Fiber Optic Mux/Demux
>
>Bruce Bowling <bowling@CEBAF.GOV> wrote:
>>I wish to take 8 digital channels and multiplex them
>>down one fiber optic cable, and demux them back into
>>8 channels. The fastest changing signal is around
>>0.1 milliseconds.
>
>I think it is time for a sanity check here.  First of all, does
>the last sentence above imply that you expect to update each channel
>every 100 microseconds?  Let's see .. 8 bits every 100 microcseconds
>is 12.5 microseconds/bit or 80kb/s.  And this is just for one channel
>and assumes only 8 bit resolution.  Add in some identification bits
>(three minimum) and the other channels and you are near
>1 microsecond/bit.  With a 20mHz PIC this is only 5 instructions.
>It would seem that at a minimum a UART will be needed.  The UART will
>have to run at 1mb/s.  Will your communications channel handle this?
>
>
>--
>Bob Fehrenbach    Wauwatosa, WI     bfehrenb@execpc.com
>