External optical drives are not recognized when you plug them in unless you have a disk inside. This is normal. I have several different drives and that's the way they act.
If you plug the drive in and then put in a disk, it (the disk) should be displayed on your desktop. The same will occur when burning to a blank disk. When you put the blank in the drive, it should be recognized by the software.
BTW, Windows does not act the same way. External drives, even when empty, will show up when plugged in.