Laser Technology

Lasers travel through air and water to generate an underwater explosion of sound at a remote location without the need for extra hardware. They will present their latest experimental data testing laser acoustics in a bubbly salt water tank and comparing two types of lasers.

The conversion of light into sound is possible because certain kinds of light pulses will self-compress, super heating a small volume of water. This optical compression happens because the intense laser light changes the properties of water so that it acts like a focusing lens and because slightly different colors of the laser travel at different speeds in water. The resulting explosion of steam it creates can generate a 210 decibel pulse of sound.

There are two different kinds of visible and infrared lasers to produce these pulses, which could eventually be used to encode information. Broadband laser pulses that can travel up to 20 meters through water to create acoustic pulses at precise distances are created. The laser light can also travel hundreds of meters through clear air, so one potential application is airplane-to-submarine communication. Acoustic reflections from the pings they produce could also be monitored to gather information about underwater environments, from detecting mines to mapping the bottom of the ocean floor.