Developer is a Company that develops linear and planar hydrophone arrays. The arrays are designed to be applicable in passive SONAR for listening, monitoring and direction-finding.

SONAR (SOund Navigation And Ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, communicate with or detect objects on or under the surface of the water, such as other vessels and submarines. Two types of technology share the name "sonar": passive sonar is essentially listening for the sound made by vessels; active sonar is emitting pulses of sounds and listening for echoes. The Sensing procedure in Sonar System usually is done by Hydrophones.

A hydrophone is a microphone designed to be used underwater for recording or listening to underwater sounds. Most hydrophones are based on a piezoelectric transducer that generates electricity when subjected to a pressure change. Such piezoelectric materials, or transducers, can convert a sound signal into an electrical signal since sound is a pressure wave. The new Technology of making Hydrophone is Acousto-Optic Transducer that made by Fiber Optic Sensing Technology.

Fiber optic Hydrophones is one major type of hydrophones that are of great importance to underwater and naval acoustics. The chief advantage is that problems related to the integration of traditional underwater acoustic sensing and sonar data transmission can be resolved from an entirely new perspective, thus improving the reliability and possibly decreasing the total cost of manufacture, operation and maintenance of the sonar system.

Because of its inherent directivity and unique phase processing, the Fiber Optic (FO) hydrophone possesses potential advantages in the detection of quiet underwater acoustic targets emitting low frequency and ultra-low frequency noise. Engineering applications for FO hydrophone have gradually emerged from the research laboratory, and will play an active role in the development of future sonar systems. A brief overview of the two technology (Piezoelectric and Fiber Optic) is presented from the viewpoint of sonar design, including the basic physics, principle of operation, key techniques, and applications.