Abstract: The present application relates to a method for performing optical time domain reflectometry (OTDR) on an optical fibre. The method comprises: a) setting (1010) a decision threshold of a photodetector; b) transmitting (1020) a first signal into an optical fibre, wherein the first signal comprises a sequence of optical radiation pulses based on a coded sequence; c) detecting (1030) optical radiation backscattered and/or reflected from the optical fibre using the photodetector; d) obtaining (1040) a measurement signal comprising bit sequences based on the detected optical radiation and the decision threshold of the photodetector; e) comparing (1050) the measurement signal with the first signal to obtain a correlation signal; f) adjusting (1060) the decision threshold of the photodetector; g) repeating (1070) steps (b)-(f) to obtain a plurality of correlation signals; and e) combining (1080) the plurality of correlation signals to obtain an OTDR trace of the optical fibre.

Abstract: An indicator system (200) for optical ports (125) of a passive optical communications equipment (120). The indicator system comprises a plurality of photodetectors (510) configured to detect an optical signal on the optical ports and a plurality of (140) configured to indicate on which optical ports an optical signal is detected by the photodetector. The indicator system further comprises a power source (350) configured to provide power to the photodetectors (510) and indicators (140). The power source is self-contained at the passive optical communications equipment. The power source (350) comprises a mechanical to electrical converter (410).

Abstract: There is provided an optical filter module comprising a photodetector, a transmitting-side tunable optical filter, and processing circuitry. The photodetector is configured to receive a low speed overlay signal from a transceiver of a fixed wavelength, and wherein the processing circuitry is configured to decode information relating to the fixed wavelength from the low speed overlay signal and set the transmitting-side tunable optical filter at the fixed wavelength.

Abstract: The present application relates to a free space optic (FSO) network node that includes a first receiving module configured to receive a first FSO signal comprising a first set of multiplexed wavelengths from a first direction and a second receiving module configured to receive a second FSO signal including a second set of multiplexed wavelengths from a second direction. The FSO network node further includes a first wavelength selective device configured to drop a first subset of wavelengths from the first set of multiplexed wavelengths and a second wavelength selective device configured to drop a second subset of wavelengths from the second set of multiplexed wavelengths. The present application also relates to another FSO network node, a method and a FSO ring network.

Abstract: Signal quality monitoring methods and systems. A signal quality monitoring method includes receiving, at a termination point of an optical link, an incoming transmission including one or more optical signals. The method further includes filtering a portion of the incoming transmission to select an optical signal from the one or more optical signals. The method also includes segmenting the optical signal by time to obtain a plurality of optical signal time segments, and generating a signal analysis plot using the plurality of optical time signal segments.

Abstract: An optical node (100) for multiplexing optical signals is disclosed. The optical node (100) comprises an add port (102), a common port (104), an auxiliary port (106), an optical transfer module (110), and a reflecting element (108) coupled to the auxiliary port. The optical transfer module (110) is configured to couple a signal received on the add port (102) and matching an operational wavelength of the optical node (100) to the common port (104), and to couple a signal received on the add port (102) and not matching an operational wavelength of the optical node (100) to the auxiliary port (106). The reflecting element (108) is configured to reflect a signal received on the auxiliary port (106) to the add port (102). Also disclosed are an optical transceiver and methods for operating and optical node and an optical transceiver.

Abstract: The present application relates to a method for performing optical time domain reflectometry (OTDR) on an optical fibre. The method comprises transmitting a first signal into an optical fibre, wherein the first signal comprises a sequence of optical radiation pulses based on a coded sequence, wherein each of the sequence of optical radiation pulses are separated by a fill pattern controlled by a binary sequence of high and low values.

Abstract: Embodiments described herein relate to methods and apparatuses for determining information associated with an optical component system in a network. A method for determining information associated with an optical component system in a network, wherein the optical component system includes a first optical path for transmission of a first optical signal, wherein the first optical path operates in an optical bandwidth that is different from a traffic optical bandwidth of a traffic optical path, includes: detecting at least one mechanically introduced optical loss in the transmitted first optical signal; and based on the detected at least one mechanically introduced optical loss, determining information associated with the optical component system.

Abstract: A padding unit comprising one or more fiber paddings is provided. Each of the one or more fiber paddings is for a respective one of one or more pairs of coupled channels in an optical device. At each pair of coupled channels, one channel in the pair of coupled channels is used as an upstream channel and the other channel in the pair of coupled channels is used as a downstream channel. Each fiber padding comprises a padding length of fiber configured to offset at least a part of a latency imbalance at the respective pair of coupled channels, the latency imbalance being a difference in latencies between the respective upstream and downstream channels caused by a difference in the multiplexing or demultiplexing path lengths of the respective upstream and downstream channels.

Abstract: An adaptor for an optical connector is provided. The optical connector defines first and second optical connector channels. The adaptor comprises a first part to couple to the optical connector and a second part comprising a connector portion for coupling to an optical device, in order to optically couple the first and second optical connector channels to the optical device. The first and second parts are movably coupled to one another and the first part is movable relative to the second part between first and second positions to selectively adjust a polarity of the connector portion.

Abstract: There is provided a security system for use at an enclosure containing one or more passive components of an optical communication link. The security system comprises a sensor configured to detect a physical breach of the enclosure, and an optical alert signal generator coupled to the optical communication link. The optical alert signal generator is self-powered, and configured to generate an optical alert signal and transmit the optical alert signal through the optical communication link when a physical breach of the enclosure is detected by the sensor. The optical alert signal is detectable at an entity external to the enclosure and connected to the optical communication link.

Abstract: Embodiments described herein relate to methods and apparatus for autotuning an optical system. There is provided a method including transmitting an optical signal on a first transmitter of an optical transmission unit at a predetermined wavelength, and determining whether the predetermined wavelength corresponds with an operational wavelength associated with an input port of an optical multiplexing unit to which the first transmitter is coupled. The determination is dependent on detection of a non-optical fault signal from the optical multiplexing unit.

Abstract: An add-drop network element (100) for an optical communications network. The add-drop network element comprises an optical amplifier (102) having an input port and an output port. The add-drop network element comprises also comprises an optical coupler (104) and an optical splitter (106). The optical coupler (104) comprises an add input port, a through input port and an output port, the output port of the optical coupler (104) being connected to the input port of the optical amplifier. The optical splitter (106) comprising a drop output port, a through output port and an input port, the input port of the optical splitter (106) being connected to the output port of the optical amplifier.

Abstract: An optical transceiver assembly is provided. The optical transceiver assembly comprises: an optical transceiver, wherein the optical transceiver comprises: an optical transmitter comprising an active region of a cavity laser for transmitting optical signals over a first channel of the optical transceiver; an optical receiver for receiving optical signals over a second channel of the optical transceiver; and an adaptor.

Abstract: Optical amplifier apparatus (100) comprising: an input (102) for an incoming optical signal (IN) comprising an optical supervisory channel, OSC, signal and service channel signals at channel wavelengths of a WDM channel wavelength grid; an output (112) for an outgoing optical signal (OUT); an optical amplifier, OA, (106) having an operating bandwidth including the WDM channel wavelength grid; a first optical drop filter (104) configured to drop from an IN signal an out-of-band, OOB, OSC signal at a wavelength outside the OA operating bandwidth; a second optical drop filter (108, 208) configured to drop from an IN signal an in-band, IB, OSC signal at a wavelength within the OA operating bandwidth; an OSC signal output (114) configured to output the dropped OSC signal; an OSC signal input (116) configured to receive an outgoing OOB OSC or IB OSC signal; and an optical add filter (110, 210) configured to add an outgoing OOB OSC or IB OSC signal to service channel signals at channel wavelengths of the WDM channel

Abstract: A telecommunications apparatus including a lighting apparatus, the lighting apparatus having: a plurality of light sources, an illumination state of the light sources being controllable according to control signals; circuitry connected to the plurality of light sources, wherein the circuity is configured to provide control signals to the light sources; and a plug connected to the circuitry, wherein the plug is configured to connect to an external port of a first telecommunications device, and configured as an interface for control signals from the first telecommunications device to the circuitry. The plurality of light sources are arranged such that a change in illumination state of the plurality of light sources provides a visual indication on a subject telecommunications device.

Abstract: A method of identifying a fault in an optical link comprises continually storing samples of a signal that represents a power of an optical signal received over the optical link. When a fault is detected on said optical link, at least one stored series of samples of the signal is retrieved. The method then comprises performing a classification on the retrieved series of samples, in order to classify the series of samples as resulting from one of a plurality of predefined faults.

Abstract: In a first aspect, a method performed by a management node for an optical network is provided. The optical network comprising a plurality of receivers and a plurality of amplifiers. The method comprises measurements of received power for the signals received at the receivers and target received power values for the receivers. The method further comprises inputting the received power measurements and target received power values into an optimisation process to determine gain values to be applied by the amplifiers on signals sent to the receivers. The method further comprises outputting the gain values for implementation at the amplifiers.

Abstract: Optical attenuators comprising electrochromic devices for telecommunications networks are provided. The optical attenuators are configured to reflect or refract an input optical signal using an electrochromic device, wherein the electrochromic device is configured to provide adjustable optical reflection or refraction levels.

Abstract: An add-drop network element (100) for an optical communications network. The add-drop network element comprises an optical amplifier (102) having an input port and an output port. The add-drop network element comprises also comprises an optical coupler (104) and an optical splitter (106). The optical coupler (104) comprises an add input port, a through input port and an output port, the output port of the optical coupler (104) being connected to the input port of the optical amplifier. The optical splitter (106) comprising a drop output port, a through output port and an input port, the input port of the optical splitter (106) being connected to the output port of the optical amplifier.