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.

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 optical device may include an optical subassembly and a digital signal processor (DSP). The optical device may include a radio frequency (RF) interconnect that electrically connects the optical subassembly and the DSP. The optical device may include a passive RF filter on one or more transmission lines of the RF interconnect.

A dual-use electromagnetic beam system may be used as a remote power delivery system when not needed as an offensive weapon. For example, a system for disabling or destroying uncooperative or enemy assets such as UAVs or ground vehicles may be used during “down time” to provide power to assets that are separated from prime power sources by distance or by logistics.

An optical device may include an optical subassembly and a digital signal processor (DSP). The optical device may include a radio frequency (RF) interconnect that electrically connects the optical subassembly and the DSP. The optical device may include a passive RF filter on one or more transmission lines of the RF interconnect.

A quasi-optical coupling system launches and extracts surface wave communication transmissions from a wire. At millimeter-wave frequencies, where the wavelength is small compared to the macroscopic size of the equipment, the millimeter-wave transmissions can be transported from one place to another and diverted via lenses and reflectors, much like visible light. Transmitters and receivers can be positioned near telephone and power lines and reflectors placed on or near the cables can reflect transmissions onto or off of the cables. The lenses on the transmitters are focused, and the reflectors positioned such that the reflected transmissions are guided waves on the surface of the cables. The reflectors can be polarization sensitive, where one or more of a set of guided wave modes can be reflected off the wire based on the polarization of the guided wave modes and polarization and orientation of the reflector.

Methods and systems for selectable parallel optical fiber and WDM operation may include an optoelectronic transceiver integrated in a silicon photonics die. The optoelectronic transceiver may, in a first communication mode, communicate continuous wave (CW) optical signals from an optical source module to a first subset of optical couplers on the die for processing signals in optical modulators in accordance with a first communications protocol, and in a second communication mode, communicate the CW optical signals to a second subset of optical couplers for processing signals in the optical modulators in accordance with a second communications protocol. Processed signals may be transmitted out of the die utilizing a third subset of the optical couplers. First or second protocol optical signals may be received from the fiber interface coupled to a fourth subset or a fifth subset, respectively, of the optical couplers.

A cryogenic optoelectronic data link, comprising a sending module operating at a cryogenic temperature less than 100 K. An ultrasensitive electro-optic modulator, sensitive to input voltages of less than 10 mV, may include at least one optically active layer of graphene, which may be part of a microscale resonator, which in turn may be integrated with an optical waveguide or an optical fiber. The optoelectronic data link enables optical output of weak electrical signals from superconducting or other cryogenic electronic devices in either digital or analog form. The modulator may be integrated on the same chip as the cryogenic electrical devices. A plurality of cryogenic electrical devices may generate a plurality of electrical signals, each coupled to its own modulator. The plurality of modulators may be resonant at different frequencies, and coupled to a common optical output line to transmit a combined wavelength-division-multiplexed (WDM) optical signal.

A cryogenic optoelectronic data link, comprising a sending module operating at a cryogenic temperature less than 100 K. An ultrasensitive electro-optic modulator, sensitive to input voltages of less than 10 mV, may include at least one optically active layer of graphene, which may be part of a microscale resonator, which in turn may be integrated with an optical waveguide or an optical fiber. The optoelectronic data link enables optical output of weak electrical signals from superconducting or other cryogenic electronic devices in either digital or analog form. The modulator may be integrated on the same chip as the cryogenic electrical devices. A plurality of cryogenic electrical devices may generate a plurality of electrical signals, each coupled to its own modulator. The plurality of modulators may be resonant at different frequencies, and coupled to a common optical output line to transmit a combined wavelength-division-multiplexed (WDM) optical signal.

A system for powering a network element of a fiber optic wide area network is disclosed. When communication data is transferred between a central office (CO) and a subscriber terminal using a network element to convert optical to electrical (O-E) and electrical to optical (E-O) signals between a fiber from the central office and twisted wire pair, coaxial cable or Ethernet cable transmission lines from the subscriber terminal, techniques related to local powering of a network element or drop site by the subscriber terminal or subscriber premise remote powering device are provided. Certain advantages and/or benefits are achieved using the present invention, such as freedom from any requirement for additional meter installations or meter connection charges and does not require a separate power network.