Navy Laser Testing

I thought this press release by the Naval Research Laboratory is interesting. Basically they are field testing a photo-ionization laser acoustic source.

The driving laser pulse has the ability to travel through both air and water, so that a compact laser on either an underwater or airborne platform can be used for remote acoustic generation. A properly tailored laser pulse has the ability to travel many hundreds of meters through air, remaining relatively unchanged, then quickly compress upon entry into the water. Atmospheric laser propagation is useful for applications where airborne lasers produce underwater acoustic signals without any required hardware in the water, a highly useful and efficient tool for undersea communications from aircraft.

Additional potential applications benefitting from extended underwater acoustic propagation include rapid sonar search and detection of underwater mines and vessels, and navigation using remotely generated laser acoustic beacons.

A lot more details in the press release.