It's not the fiber optic cable that is causing any interference to your scanner since it doesn't operate on frequencies your scanner will pick up. What may be causing interference is the ONT (that box the fiber optic cable plugs into that converts the light to the electrical signals your phone, computer, and cable-tv boxes use. The ONT is known for having interference issues, but generally this is due to issues with your router (for internet) or coax distribution (for TV).
You may have some unternimated connections on the coax. You may have some damaged coax. You may have some old coax. You may have some old splitters or amps. You may have some connections that aren't correctly tightened. All can cause the Cable-TV signal to leak out of the feed and reach your scanner. Since the Cable-TV signals use a very wide path of frequencies, it's easy for your scanner to pick them up if there are issues with your installation.
There is a known issue with the Fios ONT that's too close to a "smart meter" where the signals from the electric meter causes interference with the ONT, causing pixilation on the TV and intermittent outages on the internet side. It is recommended that the ONT be mounted no closer than 18" away from the smart meter.
This thread also discusses interference issues folks that have Fios experienced. http://forums.radioreference.com/hf-...izon-fios.html