Optical Phono Cartridges

OK, I have been out of the "newest item" game since I sold my shop years ago, but recently ran into the idea of optical phono cartridges.  I do use an "optical out" on my surround system, but I don't remember seeing any discussions on the Forum of these items.  If I missed the posts, I apologize for bringing up an item that has been discussed.  However, I would appreciate either a pointer to those discussions on the Forum, or to open this up to comments.