Optical would have all the problems the current RF (Iridium) solution has plus more...

* Clouds are a killer.

* Laser is highly focused - downlink would be tricky to support more than a couple of ground stations. Uplink would be extremely difficult because the uplink would have to track a (relatively) fast moving LEO satellite. Neither would lend themselves to a handheld ground station ("phone").

* Non-laser solutions likely don't have the bandwidth or the power to be effective.