I personally have not. I would have no issues using a bike with a carbon fork to tour, and a handful of touring bikes are configured that way (e.g. Jamis Aurora Elite). That said, a few caveats.
1) If the carbon fork does not have mounts for a rack (like the Specialized Tricross fork does), I would avoid putting a rack on it. The brake bosses may not be strong enough, and I'd be highly reluctant to use p-clamps, as it'd be easy to over-torque and possibly crack the fork.
2) There is really no reason to switch to a carbon fork. The weight savings are negligible in a touring context.