A first optical communication device is provided with a laser light source 3 for emitting communication light CL and a transmitting optical fiber 11 arranged in water WA and having a light incident end portion 14 on which the communication light CL is incident. The transmitting optical fiber 11 transmits the communication light CL incident on the light incident end portion 14 toward the tip end portion 15. The transmitting optical fiber 11 is provided with a core part 21 configured to transmit the communication light CL from the light incident end portion 14 toward the tip end portion 15 and a clad part 23 covering the core part, the clad part being configured to emit at least a part of the communication light CL that transmits the core part 21 from a side surface of the transmitting optical fiber 11.

An array of preferably electrically small scatterers is spaced at more or less regular intervals from a central transmitter. Each scatterer element includes a tunable or static reactive load which allows the propagation and fields generated by the central transmitter to be precisely controlled. Each scatterer element in the array also includes a resistive element whose value may change as a function of a distance between each scatterer and the central transmitter and which typically increases as a function of that distance. The central transmitter in the array nominally comprises an antenna, matching network, RF driver, and a vehicle, which may be a maritime vehicle or platform. The antenna for this transmitter may be comprised of an electrically small monopole oriented normal to the surface of the ocean or an electrically small loop antenna oriented with its magnetic moment parallel to the surface of the ocean.

An array of preferably electrically small scatterers is spaced at more or less regular intervals from a central transmitter. Each scatterer element includes a tunable or static reactive load which allows the propagation and fields generated by the central transmitter to be precisely controlled. Each scatterer element in the array also includes a resistive element whose value may change as a function of a distance between each scatterer and the central transmitter and which typically increases as a function of that distance. The central transmitter in the array nominally comprises an antenna, matching network, RF driver, and a vehicle, which may be a maritime vehicle or platform. The antenna for this transmitter may be comprised of an electrically small monopole oriented normal to the surface of the ocean or an electrically small loop antenna oriented with its magnetic moment parallel to the surface of the ocean.

An underwater communications system may include a first device and a second device being movable relative to one another. The first device may include a first laser transmitter configured to generate a first laser beam having a selectable spatiotemporal beam shape from among a plurality thereof, and a first controller coupled to the first laser transmitter and configured to select a spatiotemporal beam shape for the first laser beam from among the spatiotemporal beam shapes. The second device may include a second laser receiver configured to receive the first laser beam, and a second controller coupled to the second laser receiver.

An underwater communications system may include a first device and a second device being movable relative to one another. The first device may include a first laser transmitter configured to generate a first laser beam having a selectable spatiotemporal beam shape from among a plurality thereof, and a first controller coupled to the first laser transmitter and configured to select a spatiotemporal beam shape for the first laser beam from among the spatiotemporal beam shapes. The second device may include a second laser receiver configured to receive the first laser beam, and a second controller coupled to the second laser receiver.

Provided herein are hybrid optical/acoustic wireless communications platforms for aquatic environments, the platforms comprising: an optical communications system configured to send and receive optical communications signals along a bed of the aquatic environment; an optical/acoustic communications signal converter; and an acoustic communications system configured to send and receive acoustic communications signals between the bed of the aquatic environment and a surface of the aquatic environment.

Provided herein are hybrid optical/acoustic wireless communications platforms for aquatic environments, the platforms comprising: an optical communications system configured to send and receive optical communications signals along a bed of the aquatic environment; an optical/acoustic communications signal converter; and an acoustic communications system configured to send and receive acoustic communications signals between the bed of the aquatic environment and a surface of the aquatic environment.

A wireless audio streaming system for swimmers and underwater applications uses directional transmission antennas, one or more reception antennas worn on a user, and a combination of radio frequency and near-field magnetic induction communication, for streaming audio to a swimmer, buffering the streamed audio, and allowing the user to play the audio on a wireless, waterproof headset.

A wireless audio streaming system for swimmers and underwater applications uses directional transmission antennas, one or more reception antennas worn on a user, and a combination of radio frequency and near-field magnetic induction communication, for streaming audio to a swimmer, buffering the streamed audio, and allowing the user to play the audio on a wireless, waterproof headset.

The present invention discloses is a multi-band hyperbolic frequency modulation spread spectrum communication method based on cross sub-band division. In the present solution, multi-band division of different sub-band quantities is performed on an available bandwidth of an underwater acoustic system according to the parity of the serial number of the current spread spectrum period to achieve the aim of cross sub-band division. On this basis, a plurality of divided sub-bands are grouped in pairs; for each group, sub-band selection is performed according to different transmitted data by using a sub-band selection and activation method to realize multi-band parallel transmission. Meanwhile, in each spread spectrum period, an activated sub-band performs frequency modulation on a modulated signal by using rising and falling hyperbolic frequency modulation signals respectively.