The DVD Burner Optiarc AD-7700S is a slimline drive. The Optiarc AD7703 burner adds support for Labelflash but both drives share the same hardware and only differ in firmware. However you should not try to simply flash an Optiarc 7703S firmware on an Optiarc 7700S drive or vice versa. This will NOT work.
The following firmwares are available for download here:
Overview on the used writing strategies