A communication device includes: a switching unit connected to a transmission unit, a reception unit, a transmission port, and a reception port, the switching unit being set in a first state in which the transmission unit and the transmission port are connected and the reception unit and the reception port are connected or a second state in which the transmission unit and the reception port are connected and the reception unit and the transmission port are connected; a monitoring unit configured to monitor a light level of light input from the reception port or the transmission port; and a control unit configured to set the switching unit in the first state or the second state based on the light level monitored by the monitoring unit.

A communication device includes: a switching unit connected to a transmission unit, a reception unit, a transmission port, and a reception port, the switching unit being set in a first state in which the transmission unit and the transmission port are connected and the reception unit and the reception port are connected or a second state in which the transmission unit and the reception port are connected and the reception unit and the transmission port are connected; a monitoring unit configured to monitor a light level of light input from the reception port or the transmission port; and a control unit configured to set the switching unit in the first state or the second state based on the light level monitored by the monitoring unit.

An optical communication system includes a plurality of optical transmitters, a plurality of first optical couplers provided respectively corresponding to the plurality of optical transmitters, a plurality of optical receivers, and a plurality of second optical couplers provided respectively corresponding to the plurality of optical receivers, in which each of the plurality of first optical couplers splits an optical signal transmitted by the corresponding optical transmitter and outputs the optical signal to each of the plurality of second optical couplers, each of the plurality of second optical couplers merges a plurality of optical signals output from the plurality of first optical couplers and outputs the merged signal to the corresponding optical receiver, and the plurality of optical transmitters alternately transmits the optical signals.

An ONU includes a communication unit, an abnormal light emission prevention unit, and a control unit that transmits a data signal and a transmission permission signal to the communication unit and transmits the transmission permission signal to the abnormal light emission prevention unit between a transmission start time and a transmission end time. When the transmission permission signal is received, the communication unit, transmits an optical signal to an OLT, and transmits an operation signal to the abnormal light emission prevention unit during the transmission of the optical signal. The abnormal light emission prevention unit transmits a stop signal to the communication unit when a difference between a time for which the transmission permission signal is received and a time for which the operation signal is received is greater than or equal to a threshold value. The communication unit stops when the stop signal is received.

An ONU includes a communication unit, an abnormal light emission prevention unit, and a control unit that transmits a data signal and a transmission permission signal to the communication unit and transmits the transmission permission signal to the abnormal light emission prevention unit between a transmission start time and a transmission end time. When the transmission permission signal is received, the communication unit, transmits an optical signal to an OLT, and transmits an operation signal to the abnormal light emission prevention unit during the transmission of the optical signal. The abnormal light emission prevention unit transmits a stop signal to the communication unit when a difference between a time for which the transmission permission signal is received and a time for which the operation signal is received is greater than or equal to a threshold value. The communication unit stops when the stop signal is received.

Novel tools and techniques are provided for implementing visual impairment detection for free-space optical communication (“FSOC”) systems. In various embodiments, a computing system might receive, either from a camera or from a database, images (and/or videos) of an optical field of view (“FOV”) of the camera, the optical FOV comprising an optical beam(s) of a first FSOC system; might autonomously analyze the captured images (and/or videos) to determine whether an object(s) is moving within proximity to an optical beam(s) of the first FSOC system, to perform at least one of reactive learning or proactive learning regarding potential interruption of the optical beam(s) of the first FSOC system, and/or to determine one or more preventative measures to prevent interruption of the optical beam(s) of the first FSOC system; and might autonomously initiate one or more first tasks and/or the one or more preventative measures, based on the analysis.

Systems and methods include, responsive to a fault affecting an optical service on an active path in an optical network operating at a frequency μ1 via an optical transceiver and having optical line protection via an optical protection switch, switching to an inactive path that now becomes the active path and finding a new route in the optical network for the inactive path that has the fault; responsive to being unable to find a route at the frequency μ1, switching the inactive path to a new route at a different frequency μ2; and implementing spectrum coordination relative to the inactive path to either determine the frequency μ1 is available on the new route or to find another new route for the inactive path where the frequency μ1 is available.

Systems and methods include, responsive to a fault affecting an optical service on an active path in an optical network operating at a frequency μ1 via an optical transceiver and having optical line protection via an optical protection switch, switching to an inactive path that now becomes the active path and finding a new route in the optical network for the inactive path that has the fault; responsive to being unable to find a route at the frequency μ1, switching the inactive path to a new route at a different frequency μ2; and implementing spectrum coordination relative to the inactive path to either determine the frequency μ1 is available on the new route or to find another new route for the inactive path where the frequency μ1 is available.

Even in a case where light sources at an optical transmission-side and an optical reception-side are made into a common light source, a optical transmission function and an optical reception function are enabled to be used at a time.

An optical transmission/reception device according to the present invention includes optical split means for splitting the light from the optical output means into a first split light and a second split light, optical power adjustment means for respectively adjusting the optical power of the first split light and the optical power of the second split light, optical transmission means for modulating the first split light whose optical power is adjusted, and outputting the modulated first split light as a first optical signal, optical reception means for receiving the second split light whose optical power is adjusted and a second optical signal given from an outside by causing the second split light and the second optical signal to be interfered with each other, and control means for controlling the optical power adjustment means in accordance with an optical property of the output light.

Even in a case where light sources at an optical transmission-side and an optical reception-side are made into a common light source, a optical transmission function and an optical reception function are enabled to be used at a time.

An optical transmission/reception device according to the present invention includes optical split means for splitting the light from the optical output means into a first split light and a second split light, optical power adjustment means for respectively adjusting the optical power of the first split light and the optical power of the second split light, optical transmission means for modulating the first split light whose optical power is adjusted, and outputting the modulated first split light as a first optical signal, optical reception means for receiving the second split light whose optical power is adjusted and a second optical signal given from an outside by causing the second split light and the second optical signal to be interfered with each other, and control means for controlling the optical power adjustment means in accordance with an optical property of the output light.