For government agencies, part of the appeal is security. Optical signals travel in a narrow beam of light, making them harder to intercept or jam than radio frequency signals.

“You may send the RF beam to the satellite you intend to, but behind it in the shadow there is another” satellite, said Shantanu Gupta, Aerospace Corp. chief engineer for optical communications. “Interference will happen because the [RF] beam is 1,000 to 10,000 times broader than the optical beam.”