A storage controller is provided with an optical circuit switch (OCS) for managing active-passive backend storage arrays. For this purpose a system includes a host computer system, a backend storage array having a first controller and a second controller, an optical circuit switch (OCS) connected between the host computer system and the first and second controllers, and a storage system controller comprising a failover detector to detect a failover of the first controller when the first controller is in an active state and the second controller is in a passive state, and an OCS controller to control the OCS to switch connection of the host computer system from the first controller to the second controller based on the failover detector detecting a failover of the first controller to place the second controller in an active state.

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.

The present invention discloses a passive optical network communications method, apparatus and system. The method includes: receiving, by an optical network unit, a first message sent by an optical line terminal, where the first message carries backup wavelength channel ID information; switching, by the optical network unit, following the optical network unit detects a fault, an operating wavelength channel of the optical network unit to a backup wavelength channel identified by the backup wavelength channel ID information; and performing, by the optical network unit, data communication over the switched-to backup wavelength channel. In this way, fast protection switching of a passive optical network system is implemented and reliability of the system is improved.

A software-defined redundant passive optical network (SD RPON) system having a passive optical network (PON) provider's server with an access network. The access network has a primary path to an optical line terminal (OLT) connected to an optical network terminal (ONT), wherein the ONT is connected to a customer's equipment to receive a PON signal and PON services. The access network also has one or more protection paths extending to another OLT connected to the ONT. An auto-detection system monitors PON signal transmission through the access network and an auto-assignment system assigns an ONT to the customer through using a customer's unique identifier. The SD RPON system automatically moves a customer from an existing ONT to another ONT if PON signal transmission fails through the existing ONT and serves a diverse path protection, while offering tremendously simplified and time-saving disaster recovery.

Disclosed herein is a method of transmitting data in an optical network (10, 100) from a first location to a second location, as well as a corresponding receiver unit and transceiver. The method comprises the following steps: modulating a same data signal on first and second carriers having first and second wavelengths, respectively, to generate first and second optical signals carrying the same information, transmitting said first and second optical signals from said first location to said second location through said optical network, coherent receiving of a selected one of said first and second optical signals by means of a coherent receiver (29) located at said second location, wherein said coherent receiving comprises the following steps: receiving a selected one or both of said first and second optical signals on a photodetector (30a, 30b), providing, by means of a local oscillator arrangement (34, 38) optically connected with said photodetector (30a, 30b), a selected one of a first local oscillator signal having a wavelength corresponding to said first wavelength and a second local oscillator signal having a wavelength corresponding to said second wavelength, in case both of said first and second optical signals are received on said photodetector, or both of said first and second local oscillator signals in case a selected one of said first and second optical signals is received on said photodetector; and processing the output signal of said photodetector by means of an electronic receiver circuit (32) connected to said photodetector (30a, 30b).

A network switch device and an operating method therefor are provided. The method includes: receiving, by a logic unit, a plurality of interrupt control signals from a plurality of optical fiber data transceivers, where each of the interrupt control signals reflects whether an operating state of each of the optical fiber data transceivers becomes anomalous or changes; combining, by the logic unit, the interrupt control signals from the optical fiber data transceivers into an interrupt combined signal; receiving, by an interrupt control pin of a processing unit, the interrupt combined signal; determining, by the processing unit, whether a logic level of the interrupt combined signal changes; and if the processing unit determines that the logic level of the interrupt combined signal changes, executing, by the processing unit, an interrupt handler, and determining which one of the optical fiber data transceivers becomes anomalous or changes.

A passive fiber optic switching (PFOS) device may provide failover in a fiber optic network by switching a working path between different fibers of a redundant set of fibers. The PFOS device may operate passively (e.g., without an active, external, and/or continuous power supply) by harvesting the power that it needs from the light that passes over any one or more fibers that are connected to the PFOS device. The PFOS device may detect issues that disrupt signaling and/or light transmission on the working path based on quality (e.g., signaling and/or light properties) of the working path, and/or diagnostic messaging received from other devices on the working path. The PFOS device may include an optical switch, such as a Micro-Electro-Mechanical System (MEMS) mirror switch, that can change the working path by switching light to any fiber of the redundant set of fibers.

A system for performing failover switches in an optical network, such as a time and wavelength division passive optical networks (TWDM PON) like NG-PON2, includes a backup optical line terminal (OLT) for backing up communications of a primary OLT. The backup OLT is configured to allocate small upstream time slots, referred to herein as de minimis time slots, to at least one optical network terminal (ONT) communicating with the primary OLT during normal operation. When a failure occurs that prevents communication between the ONT and the primary OLT, the ONT autonomously tunes to the upstream and downstream wavelength pairs of the backup OLT and begins to transmit data to the backup OLT in the de minimis time slot allocated to it. The presence of data in the de minimis time slot indicates the occurrence of a failover switch to the backup OLT, and the backup OLT then begins to allocate time slots to this ONT, which is normally serviced by the primary OLT according to its normal TDM algorithm.

An apparatus includes a first reconfigurable optical add/drop multiplexer (ROADM) to receive a first optical signal and a second ROADM to receive a second optical signal. The apparatus also includes a reconfigurable optical switch that includes a first switch, switchable between a first state and a second state, to transmit the first optical signal at the first state and block the first optical signal at the second state. The reconfigurable optical switch also includes a second switch, switchable between the first state and the second state, to transmit the second optical signal at the first state and block the second optical signal at the second state. The reconfigurable optical switch also includes an output port to transmit an output signal that is a sum of possible optical signals transmitted through the first switch and the second switch.

A storage controller is provided with an optical circuit switch (OCS) for managing active-passive backend storage arrays. For this purpose a system includes a host computer system, a backend storage array having a first controller and a second controller, an optical circuit switch (OCS) connected between the host computer system and the first and second controllers, and a storage system controller comprising a failover detector to detect a failover of the first controller when the first controller is in an active state and the second controller is in a passive state, and an OCS controller to control the OCS to switch connection of the host computer system from the first controller to the second controller based on the failover detector detecting a failover of the first controller to place the second controller in an active state.