A method of implementing a stretched single optical communication span includes receiving one or more optical signals from an optical fiber span having high loss; adding a pilot signal to the one or more optical signals, subsequent to the receiving; and amplifying the one or more optical signals and the pilot signal with a pre-amplifier that is an Erbium Doped Fiber Amplifier (EDFA). Advantageously, the stretched single span operates below a Hazard 1M environment. A node in a stretched single optical communication span includes an optical multiplexer connected to an optical fiber span having high and a pilot signal, and configured to output a combination of one or more optical signals from the optical fiber span and the pilot signal; and a pre-amplifier that is an EDFA configured to receive the output of the optical multiplexer and provide amplification of the one or more optical signals and the pilot signal.

An optical device having a self-repair component capable of curing a defective component(s) is disclosed. To improve reliability as well as manufacturing yield, a photonic integrated circuit (PIC) for as a multi-channel optical line terminal (OLT) contains spare lasers or standby lasers configured to replace a failed laser(s). In one aspect, PIC includes a set of fixed-wavelength lasers (FWLs), a tunable-wavelength auxiliary laser (TWAL), a photonic detector, and a tuner. FWLs, for example, generate optical wavelengths representing optical signals. TWAL generates an optical signal with a spectrum of wavelengths based on a setting generated by the tuner. The photonic detector detects a defective wavelength. The tuner adjusts output wavelength of TWAL in response to the defective wavelength. Alternatively, PIC includes a working laser array, standby laser array, and spare laser array capable of providing two layer laser defective protections.

An optical transmission apparatus for transmitting a main signal, the optical transmission apparatus being arranged on an optical transmission line, the optical transmission apparatus includes a first processor configured to perform alarm supervision and signal control of the optical transmission apparatus; a second processor configured to perform the alarm supervision and the signal control of the optical transmission apparatus during a period when the first processor is in a stopped state; inter-apparatus transmitter and receivers configured to transmit and receive a signal including control information for the alarm supervision between the first and second processors and another optical transmission apparatus facing the optical transmission apparatus; and a multiplexer and demultiplexer configured to couple and split the signal for the main signal optically communicated with the another optical transmission apparatus.

To provide an optical communication technology that brings flexibility to ROADM systems. An optical communication device according to the present invention drops and adds an optical signal from and to wavelength-division multiplexed optical signals that are transmitted on a main path between network terminal stations, the device including: first means and second means capable of selecting an optical signal of a predetermined wavelength from inputted optical signals and of outputting the selected optical signal; third means for splitting optical signals inputted from a first terminal station on the main path into the first means and the second means; fourth means for splitting optical signals inputted from a branch path in the network into the first means and the second means; and fifth means capable of selectively outputting to a second terminal station on the main path either an optical signal outputted by the first means or an optical signal outputted by the second means.

The present disclosure relates to systems and method for deploying a fiber optic network. Distribution devices are used to index fibers within the system to ensure that live fibers are provided at output locations throughout the system. In an example, fibers can be indexed in multiple directions within the system. In an example, spare ports can be providing in a forward direction and reverse direction ports can also be provided.

In some embodiments, an apparatus includes an optical transceiver that includes a first set of electrical transmitters operatively coupled to a switch. Each electrical transmitter from the first set of electrical transmitters is configured to transmit an electrical signal from a set of electrical signals. In such embodiments, the switch is configured to switch an electrical signal from the set of electrical signals such that the set of electrical signals are transmitted via a second set of electrical transmitters. Each electrical transmitter from the second set of electrical transmitters is operatively coupled to an optical transmitter from a set of optical transmitters. The set of optical transmitters is operatively coupled to an optical multiplexer. In such embodiments, at least one electrical transmitter from the second set of electrical transmitters is associated with a failure within the optical transceiver.

A transceiver can include a transmitter and a receiver. The transmitter can include: a primary laser emitter; a primary monitor photodiode optically coupled with the laser emitter; a spare laser emitter; and a transmitter integrated circuit having a primary channel operably coupled with the primary laser emitter; a spare channel operably coupled with the spare laser emitter; a switch on the primary channel; and a secondary channel operably coupled with the switch and the spare channel. The receiver can include: a primary detector photodiode; a spare detector photodiode; and a receiver integrated circuit a primary receiver channel operably coupled with the at least one primary detector photodiode; a spare receiver channel operably coupled with the spare detector photodiode; a receiver switch on the spare receiver channel; and a secondary receiver channel operably coupled with the receiver switch and the primary receiver channel.

A transport network is configured to connect one or more optical rings of optical add and drop devices with one or more digital units in a radio access network. The transport network comprises a first electronic cross-connect and a second electronic cross-connect. A switch is provided for connecting the first electronic cross-connect and/or the second electronic cross-connect to the one or more digital units. The first and second electronic cross-connects are each coupled to at least one of the one or more optical rings of optical add and drop devices.

In order to improve the reliability of a reconfigurable optical add/drop multiplexing (ROADM) device, provided is an optical add/drop device that comprises the following: a first wavelength selection unit and a second wavelength selection unit that can select and output an optical signal of a prescribed wavelength from among inputted optical signals; a first branching unit that selectively outputs a first signal being an optical signal that has been inputted from a first terminal station on a main route to the first wavelength selection unit and the second wavelength selection unit; a second branching unit that selectively outputs a second signal being an optical signal that has been inputted from a second terminal station on a sub-route to the first wavelength selection unit and the second wavelength selection unit; and a first output unit that can selectively output to the second terminal station, as a third signal, either the optical signal outputted by the first wavelength selection unit on the basis of the first signal and the second signal, or the optical signal outputted by the second wavelength selection unit on the basis of the first signal and the second signal.

An optical device having a self-repair component capable of curing a defective component(s) is disclosed. To improve reliability as well as manufacturing yield, a photonic integrated circuit (PIC) for as a multi-channel optical line terminal (OLT) contains spare lasers or standby lasers configured to replace a failed laser(s). In one aspect, PIC includes a set of fixed-wavelength lasers (FWLs), a tunable-wavelength auxiliary laser (TWAL), a photonic detector, and a tuner. FWLs, for example, generate optical wavelengths representing optical signals. TWAL generates an optical signal with a spectrum of wavelengths based on a setting generated by the tuner. The photonic detector detects a defective wavelength. The tuner adjusts output wavelength of TWAL in response to the defective wavelength. Alternatively, PIC includes a working laser array, standby laser array, and spare laser array capable of providing two layer laser defective protections.