Aspects of an optical communications network are described that include two or more optical fibers arranged to allow communication in the same direction. The optical network includes a first optical amplifier coupled to the first optical fiber, a second optical amplifier coupled to the second optical fiber, a first optical pump to provide optical power to the first optical fiber, and a second pump to provide optical power to both the first and the second optical fibers. By sharing the second pump between the first and the second optical fibers, a need to deploy additional pumps is alleviated. Scaling of the optical network to include additional optical fibers provides further cost savings by allowing more pumps to be shared among the multiple optical fibers.

An optical coupling element is configured to be positioned between and optically couple a first optical component configured to transmit a light beam, and a second optical component configured to receive light. The optical coupling element comprises a glass coupler body having a receiving side surface and an opposite transmitting side surface. The glass coupler body comprises a converging member configured to reduce divergence of light entering the glass coupler body via the receiving side surface; and a coupling waveguide extending within the glass coupler body between the converging member and an output facet on the transmitting side surface and being configured to transmit light from the converging member to the output facet.

In an example, the present invention provides a quantum repeater system and its application to quantum network. The quantum repeater system includes a nano-fiber based quantum computer device.

A communications device is disclosed and includes: a first acquiring unit for acquiring first specific wavelength light and second specific wavelength light from a first optical path; a first receiving unit for converting the first specific wavelength light coming from the first acquiring unit into a first electrical signal; a first control unit for sending a first modulating signal to a first loopback unit according to the first electrical signal coming from the first receiving unit; and the first loopback unit for modulating the second specific wavelength light coming from the first acquiring unit according to the first modulating signal, and looping the modulated second specific wavelength light back to a second optical path, where a transmission direction of an optical signal in the second optical path is opposite to a transmission direction of an optical signal in the first optical path. The present invention further discloses a communications method.

Techniques for extending distributed acoustic sensing (DAS) range in undersea optical cables are provided. For example, DAS range can be extended by transmitting and amplifying a DAS signal along multiple spans of a first optical fiber, routing or bypassing the DAS signal from the first optical fiber to a second optical fiber different from the first fiber via a high-loss loopback architecture, and returning and amplifying the DAS signal along the same multiple spans back to a DAS device. The DAS device may then receive and process the DAS signal to detect any changes in the DAS environment. The loopback configuration may be based on different types of loopback architecture.

In an example, the present invention provides a quantum repeater system and its application to quantum network. The quantum repeater system includes a nano-fiber based quantum computer device.

In an example, the present invention provides a quantum repeater system and its application to quantum network. The quantum repeater system includes a nano-fiber based quantum computer device.