Described herein is a space based subsystem of a satellite, and methods for use therewith, for producing and transmitting an optical ISL beam to another satellite. The subsystem can include, inter alia, receiver optics, optical amplifiers, a WDM demultiplexer, beam splitters, a WDM multiplexer, and transmitter optics. The transmitter optics may be configured to receive an amplified wavelength division multiplexed optical signal and, in dependence thereon, transmit an optical ISL beam to another satellite. In certain embodiments, because RF frequencies of a wavelength division multiplexed optical signal produced by the WDM multiplexer are within a same specified RF frequency range within which the other satellite is configured to transmit RF service downlink beams, there is an elimination of any need for the other satellite to perform any frequency conversions when producing the RF service downlink beams in dependence on the optical ISL beam.

An apparatus comprising an arrayed waveguide grating (AWG) comprising a plurality of AWG ports, a power splitter comprising a plurality of splitter ports, and a plurality of optical interleavers, each coupled to a respective AWG port and a respective splitter port, for directing incoming optical signals to one of the AWG and the power splitter.

The temperature at different locations along a multiplexed laser array may be monitored by sensing temperature at two locations within a transmitter optical subassembly (TOSA) package housing the laser array. The temperature at the two locations is used to determine a temperature tilt across the laser array. Estimated temperatures may then be determined at one or more other locations along the laser array from the temperature tilt. The estimated temperature(s) may then be used to adjust the temperature proximate the other locations, for example, for purposes of tuning lasers at those locations along the laser array to emit a desired channel wavelength. The TOSA package may be used in an optical transceiver in a wavelength division multiplexed (WDM) optical system, for example, in an optical line terminal (OLT) in a WDM passive optical network (PON).

A telecommunications module includes an optical wavelength division multiplexer/demultiplexer configured to demultiplex a first optical signal input into the telecommunications module into a plurality of different wavelengths, a fiber optic splitter configured to split a second optical signal input into the telecommunication module into a plurality of optical signals, and a plurality of optical add/drop filters, each of the optical add/drop filters configured to combine one of the optical signals that has been split by the fiber optic splitter and one of the wavelengths that has been demultiplexed by the optical wavelength division multiplexer/demultiplexer into a combination output signal that is output from the telecommunications module.

In order to prevent a signal which a terminal station does not require from being intercepted by the terminal station without greatly changing the power of optical signals to be transmitted from a node to the terminal station, a node device is provided with: a first optical unit which outputs a first optical signal received from a first terminal station and addressed to a second terminal station, and a second optical signal received from the first terminal station, addressed to a third terminal station, and having a different wavelength band from the first optical signal; and a second optical unit to which the first and second optical signals outputted from the first optical unit are inputted, and which shifts the frequency of the first optical signal by a predetermined amount to create a fourth optical signal, passes the second optical signal without any change, couples the second and fourth optical signals, and transmits a resultant signal to the third terminal station.

A method is provided for detecting intrusion into optical fibers of a Passive Optical Network (PON) of the type which includes a multiplexing system at the head end for separating a data signal output at the head end to the plurality of fibers for supply to user end terminals and a data transmission system at each of the user end terminals for entering onto the fiber data as an optical signal. The method includes providing a monitor system having a transmitter at the head end and a monitor signal analysis system for analyzing changes in the optical monitor signal after transmission along the fiber for detecting an intrusion event. A monitor signal analysis system is provided at one or more user end terminals for detection and conversion of data from the analysis into a digital signal which is then transmitted from the user end terminals back to the head end using the data transmission system through the PON system or separately from the PON system.

An apparatus includes an optical wavelength multiplexer to multiplex a sequence of optical wavelength channels. The optical wavelength multiplexer comprises a first passive optical filter to combine odd channels of the sequence of optical wavelength channels into a first multiplexed optical signal, a second passive optical filter to combine even channels of the sequence of optical wavelength channels into a second multiplexed optical signal, and an optical combiner to combine the odd channels and the even channels into a composite optical signal. The optical wavelength multiplexer comprises variable optical attenuators, and an electronic controller to operate the variable optical attenuators to substantially block one or more adjacent optical wavelength channels adjacent to a particular optical wavelength channel provisioned to the optical wavelength multiplexer in response to a width for the particular optical wavelength channel being larger than a width of the adjacent optical wavelength channel(s).

According to examples, an apparatus may include a wavelength division multiplexing (WDM) module including a WDM housing having a WDM front panel and a WDM component housed within the WDM housing. The apparatus may also include an optical time-domain reflectometer (OTDR)/switch module integrated with the WDM module, the OTDR/switch module including an OTDR housing having an OTDR front panel and an OTDR/switch component housed within the OTDR housing. The WDM housing may be connectable with the OTDR housing to cause respective side edges of the WDM front panel and the OTDR front panel to be adjacent to each other when the WDM housing is connected to the OTDR housing.

Provided is an optical access system that performs communication using an optical signal on which a management control signal used for management and control is superimposed, the optical access system including: a subscriber device on a transmitting side that generates an optical signal by superimposing the management control signal on a main signal and transmits the generated optical signal; a management control unit that outputs a management control signal which is superimposed on the optical signal transmitted by the subscriber device on the transmitting side and which has a frequency band different from a frequency of the management control signal superimposed on the optical signal; and a control signal superimposing unit that superimposes the management control signal output from the management control unit on the optical signal.

An example reconfigurable optical add/drop multiplexer includes: optical fibers, X first wavelength selective switches, and Y wavelength add/drop modules. The X first wavelength selective switches correspond to W directions. The W directions include a first direction and a second direction. The first direction corresponds to P first wavelength selective switches among the X first wavelength selective switches. The second direction corresponds to Q first wavelength selective switches among the X first wavelength selective switches, where P+Q is less than or equal to X. A first wavelength add/drop module is connected to A of the P first wavelength selective switches by using one or more first optical fibers, and connected to B of the Q first wavelength selective switches by using one or more second optical fibers, where the first wavelength add/drop module is one of the Y wavelength add/drop modules, A is less than P.