A method and apparatus for wavelength allocation for bidirectional optical access. The wavelength allocation method sets a first central wavelength for the optical path terminal to perform downstream transmission to the optical network unit, and a second central wavelength for the optical network unit to perform upstream transmission to the optical network terminal. At this time, the first center wavelength and the second center wavelength are separated by a predetermined wavelength interval, and the first center wavelength is set larger than the second center wavelength.

Systems and methods for optical modulation index calibration in a CATV network.

A laser light generator is configured to generate one or more wavelengths of continuous wave laser light. The laser light generator is configured to collectively and simultaneously transmit each of the wavelengths of continuous wave laser light through an optical output of the laser light generator as a laser light supply. An optical fiber is connected to receive the laser light supply from the optical output of the laser light generator. An optical distribution network has an optical input connected to receive the laser light supply from the optical fiber. The optical distribution network is configured to transmit the laser light supply to each of one or more optical transceivers and/or optical sensors. The laser light generator is physically separate from each of the one or more optical transceivers and/or optical sensors.

Optical fiber-based wireless systems and related components and methods are disclosed. The systems support radio frequency (RF) communications with clients over optical fiber, including Radio-over-Fiber (RoF) communications. The systems may be provided as part of an indoor distributed antenna system (IDAS) to provide wireless communication services to clients inside a building or other facility. The systems incorporate various functions, such as optical network terminal (ONT), splitter, and local powering, in antenna coverage areas.

A method for in-field calibration of a laser transmitter includes receiving, at an optical network unit (ONU), a downstream connection from an optical line terminal (OLT) where the ONU includes a Distributed Bragg Reflector (DBR) laser. The method further includes attempting to establish an upstream connection between the ONU and the OLT. When the ONU establishes the upstream connection to the OLT, the method also includes receiving, at the ONU, a message to initiate calibration of the ONU where the message is generated to indicate that the DBR laser is operating outside an operational state. The method further includes tuning, by the ONU, the DBR laser to the operational state by adjusting an injection current for the DBR laser.

An optical transceiver includes a wavelength-tunable transmission unit configured to transmit an optical transmission signal, a wavelength-tunable reception unit configured to receive an optical reception signal, a wavelength table configured to store a plurality of combinations of a transmission wavelength and a reception wavelength, an input terminal configured to input a wavelength selection signal, and a control unit configured to select one combination of the transmission wavelength and the reception wavelength from the wavelength table based on the wavelength selection signal, and perform transmission wavelength control for setting the selected transmission wavelength in the wavelength-tunable transmission unit as a wavelength of the optical transmission signal and reception wavelength control for setting the selected reception wavelength in the wavelength-tunable reception unit as a wavelength of the optical reception signal.

A method in a first level aggregation node of a transport network is disclosed. The transport network comprises the first level aggregation node, a second level aggregation node and a Passive Optical Network. T the method comprises receiving, from the second level aggregation node, a plurality of wavelength division multiplexing (WDM) channels having wavelengths in a first spectrum section and generating at least one passive optical channel having a wavelength in a second spectrum section, different to the first spectrum section. The method further comprises combining at least some of the WDM channels received from the second level aggregation node with the at least one passive optical channel, and forwarding the combined WDM channels and passive optical channel to a termination node in the Passive Optical Network. Also disclosed are a method in a termination node of a transport network, a first level aggregation node, a termination node and a computer program.

A laser light generator is configured to generate one or more wavelengths of continuous wave laser light. The laser light generator is configured to collectively and simultaneously transmit each of the wavelengths of continuous wave laser light through an optical output of the laser light generator as a laser light supply. An optical fiber is connected to receive the laser light supply from the optical output of the laser light generator. An optical distribution network has an optical input connected to receive the laser light supply from the optical fiber. The optical distribution network is configured to transmit the laser light supply to each of one or more optical transceivers and/or optical sensors. The laser light generator is physically separate from each of the one or more optical transceivers and/or optical sensors.

A remote node includes a first node input, a second node input, and an optical switch. The optical switch includes a first switch input optically coupled to the first node input, a second switch input optically coupled to the second node input, a first switch output switchably coupled to the first switch input or the second switch input, and a second switch output switchably coupled to the first switch input or the second switch input. The remote node includes a photodiode optically coupled to the second switch output, and a capacitor electrically coupled to the photodiode and the optical switch. When the first switch input is switchably coupled to the first switch output, the second switch input is switchably coupled to the second switch output. Light received by the second switch input passes out the second switch output to the photodiode. The photodiode charges the capacitor to a threshold charge.

A remote node includes a first node input, a second node input, and an optical switch. The optical switch includes a first switch input optically coupled to the first node input, a second switch input optically coupled to the second node input, a first switch output switchably coupled to the first switch input or the second switch input, and a second switch output switchably coupled to the first switch input or the second switch input. The remote node includes a photodiode optically coupled to the second switch output, and a capacitor electrically coupled to the photodiode and the optical switch. When the first switch input is switchably coupled to the first switch output, the second switch input is switchably coupled to the second switch output. Light received by the second switch input passes out the second switch output to the photodiode. The photodiode charges the capacitor to a threshold charge.