A wet mate optical connector in combination with a wave division multiplexer, there being a plurality of input fiber optic cables on an input side of the multiplexer and a fiber optic cable on an output side of the multiplexer connected for providing multiplexed optical signals from the input cables to the wet mate connector.

Disclosed herein is an underwater visible light transceiving terminal, which is capable of easily receiving a visible-light signal transmitted from a certain direction, through an optical-fiber assembly composed of a plurality of optical fibers that are radially arranged, and which is capable of delivering data, sent from a main communication station, in several directions in the form of a visible-light signal in the water through the optical-fiber assembly, thus allowing a submarine or a submergence robot to effectively receive the visible-light signal.

An ultra-wide bandwidth acoustic transducer may include multiple layers, including an inner piezoelectric layer, a polymer coupling layer and an outer piezoelectric layer. The polymer layer may be located between, and may be bonded to, the inner and outer piezoelectric layers. The transducer may have multiple eigenfrequencies of vibration. These eigenfrequencies may include primary resonant frequencies of the inner and outer piezoelectric layers respectively and may also include resonant frequencies that arise due to coupling between the layers. An acoustic backscatter system may employ such a transducer in backscatter nodes as well as in a transmitter. The multiple eigenfrequencies may enable the system to perform spread-spectrum communication at a high throughput. These multiple eigenfrequencies may also enable each backscatter node to shift frequency of an uplink signal, which in turn may enable the system to mitigate self-interference and to decode concurrent signals from multiple backscatter nodes.

An ultra-wide bandwidth acoustic transducer may include multiple layers, including an inner piezoelectric layer, a polymer coupling layer and an outer piezoelectric layer. The polymer layer may be located between, and may be bonded to, the inner and outer piezoelectric layers. The transducer may have multiple eigenfrequencies of vibration. These eigenfrequencies may include primary resonant frequencies of the inner and outer piezoelectric layers respectively and may also include resonant frequencies that arise due to coupling between the layers. An acoustic backscatter system may employ such a transducer in backscatter nodes as well as in a transmitter. The multiple eigenfrequencies may enable the system to perform spread-spectrum communication at a high throughput. These multiple eigenfrequencies may also enable each backscatter node to shift frequency of an uplink signal, which in turn may enable the system to mitigate self-interference and to decode concurrent signals from multiple backscatter nodes.

An apparatus is described which uses directly modulated InGaN Light-Emitting Diodes (LEDs) or InGaN lasers as the transmitters for an underwater data-communication device. The receiver uses automatic gain control to facilitate performance of the apparatus over a wide-range of distances and water turbidities.

An apparatus is described which uses directly modulated InGaN Light-Emitting Diodes (LEDs) or InGaN lasers as the transmitters for an underwater data-communication device. The receiver uses automatic gain control to facilitate performance of the apparatus over a wide-range of distances and water turbidities.

A method and apparatus for underwater acoustic communication are disclosed. A data packet frame structure in the communication transmission includes a preamble, a synchronization code, and a data code. A guard interval is disposed between the preamble and the synchronization code. This method utilizes the different impact response environments of linear frequency modulation signals in different frequency bands to obtain the mapping relationships corresponding to the characteristics of the impulse responses in the frequency band, and adopts the quadrature phase shift keying (QPSK) modulation method to convert four groups of LMF signals with different center frequencies and the same modulation frequency, representing different symbols for signal transmission, where the LFM carrier signal of each center frequency can represent two bits of binary information to improve transmission efficiency. The apparatus for underwater acoustic communication also has the above-mentioned technical effects.

A method and apparatus for underwater acoustic communication are disclosed. A data packet frame structure in the communication transmission includes a preamble, a synchronization code, and a data code. A guard interval is disposed between the preamble and the synchronization code. This method utilizes the different impact response environments of linear frequency modulation signals in different frequency bands to obtain the mapping relationships corresponding to the characteristics of the impulse responses in the frequency band, and adopts the quadrature phase shift keying (QPSK) modulation method to convert four groups of LMF signals with different center frequencies and the same modulation frequency, representing different symbols for signal transmission, where the LFM carrier signal of each center frequency can represent two bits of binary information to improve transmission efficiency. The apparatus for underwater acoustic communication also has the above-mentioned technical effects.

A system and method for optical communication between multiple UUVs, more specifically, for leader-follower formations between UUVs. The system focuses on the characterization and modeling of a 1-dimensional and/or 3-dimensional light field produced from a light source mounted on a Leader UUV, which is detected by one or more follower UUVs. Communication algorithms are used to monitor the UUV's motion and orientation utilizing simulators, look up tables, and the like. A variety of detectors arrays can be used in a variety of wavelengths depending on the desired application.

A system and method for optical communication between multiple UUVs, more specifically, for leader-follower formations between UUVs. The system focuses on the characterization and modeling of a 1-dimensional and/or 3-dimensional light field produced from a light source mounted on a Leader UUV, which is detected by one or more follower UUVs. Communication algorithms are used to monitor the UUV's motion and orientation utilizing simulators, look up tables, and the like. A variety of detectors arrays can be used in a variety of wavelengths depending on the desired application.