I believe the A320 ADIRU's (at least Honeywell one's) all are RLGs, not Fibre Optic Gyros.
Even more recent aircraft such as the 787 still utilised RLGs in its Earth Reference System components (IRU's and AHRU's).
Believe some if not all Integrated Standby Instruments (ISIS or ISFD) mostly use fibre optic gyros due to their relative size compared to RLGs and also if I remember right there are fibre optic gryos under the floor mid-cabin on the A340-600 for improving ride comfort.