I've been using the Toslink digital audio cables for a little while, the 1mm plastic fiber with 5mm outer sheath ones, from eBay a 4m one with postage from USA to UK is £3. Works fine.
I wanted a coiled section in it to shorten the apparent length, so used a hot air gun slightly heating the cable as its wrapped around a mandrel and can easily produced a coiled section (the light does get a little dizzy going round all the curves but still works :-) ).
Connecting to a Z240 I made a connector with rubber tubing which slips over the light sensor. Use tubing which slips on without much strain or also found the plastic sheath from 15mm underground copper pipe is the right size and screws onto the Z240 threads. Cut about a 30mm length of this tubing and fill half full of hot melt glue then when cold drill a hole for the optical cable. No need to worry about polishing ends or anything, just cut with a knife.
Connecting to a S&S YS90 I modified the supplied diffuser as a starting point to produce a holder that will direct the fiber optic into the flash sensor.
At the camera end, on a Nexus D200 housing the optic fiber needs to slip into the little spring loaded optical bulkhead. The audio optic fiber has multiple layers of sheath, strip back the outer 2 of these a little way leaving the inner layer. This is too thin to be gripped, but a couple of centimetres of 3.7mm outside diameter polythene tube slipped and hot melt glued over the exposed inner sheath of the optical cable is gripped and is released by pressing on the spring release ring. Works better than the proper adapter.
On a compact camera just exposed a few mm of optic cable and used black tape to hold it over the flash on the housing.
Charles
NB: I have tested this Cable and it work's just like the "Original"... 
-
