Techniques for tuning an optical communication system are disclosed. The system includes a first signal path for transmitting data, including an optical source, a first one or more variable optical attenuators (VOAs), a modulator, and a transmission fiber. The system further includes a second signal path for receiving data, including a receiver fiber and a second one more VOAs. The first one or more VOAs are tuned using the optical source in the first signal path for transmitting data, based on comparing a plurality of optical signal power values in the first path while a first tuning mode is enabled. The second one or more VOAs are tuned, using the optical source in the first signal path for transmitting data, based on comparing a plurality of optical signal power values in the second path while a second tuning mode is enabled.

An Optical Time Domain Reflectometer (OTDR) module obtains Optical Return Loss (ORL) of a fiber plant. Calibration information is obtained of at least internal OTDR reflections associated with the OTDR module. The OTDR module is connected to the fiber plant. An ORL response is measured due to reflections of an ORL signal transmitted from the OTDR module along the fiber plant, and a peak OTDR response is measured in response to reflections of an OTDR signal transmitted from the OTDR module along the fiber plant. A corrected ORL response of the fiber plant is determined by: using the measured peak OTDR response (e.g., peak value or area under the peak) and the calibration information to calculate the calculated ORL due to internal reflections, and then adjusting the measured ORL response by the calculated ORL to represent the corrected ORL of the fiber plant.

Architectures and techniques are presented that improve or enhance a network planning procedure such as by selecting a more efficient test buffer that is used to identify objects that might intersect a Fresnel zone between two transceivers. An improved test buffer (e.g., buffer region) can be one that is constructed from a plurality of rectangles situated along a line of sight of the two transceivers and that are oriented according to cardinal directions.

In an optical fiber monitoring system which detects physical disturbance or other parameters such as temperature or strain of a fiber where a monitor signal is transmitted along the optical fiber and analyzed to detect changes which are indicative of an event, a method is provided for periodically checking proper operation of the optical fiber monitoring system. A fiber disturbance actuator periodically causes a pattern of disturbances of a portion of the fiber at a predetermined location thereon where the disturbance is characteristic of the event to be monitored. The monitor signal is analyzed to detect the pattern of changes and in the event that expected changes are not detected, a warning is issued that the intrusion detection system is not properly operating.

An optical gateway includes a light sensor unit, comprising at least one light sensor, configured to sense state information of a signal lamp of an external test device; a control unit, connected to the light sensor unit, and configured to obtain the state information of the signal lamp; and a communication unit, connected to the control unit and configured to send the status information of the signal lamp to an external cloud server. The invention also provides a remote monitoring system, and the user can obtain the state information of the external test device from the cloud server, and monitor the working state of the external test device in real time through the optical gateway and the remote monitoring system.

A measurement device for polarization-maintaining optical fiber spindle difference delay is provided. The measurement device comprises a polarization-maintaining fiber (PM) Sagnac interferometer, a signal generator, a microwave detector, a microprocessor. The PM Sagnac interferometer comprises a laser, a photoelectric modulator, and a PM fiber coupler that are connected in sequence. The PM Sagnac interferometer further comprises an optical fiber interface J1 and an optical fiber interface J2 arranged at the two output ends of the PM fiber coupler, a PM fiber to be measured located between the fiber interface J1 and the fiber interface J2, and a photodetector arranged at the other output end of the PM fiber coupler.

A process of estimating a transfer function or an inverse transfer function of the optical transmitter from first data obtained by the optical receiver when a first known signal is transmitted from the transmitter to the receiver, and a temporary transfer function or a temporary inverse transfer function of the optical receiver, is performed for multiple frequency offsets between the optical transmitter and the optical receiver. At this time, the transfer function or the inverse transfer function of the optical transmitter is estimated by comparing the first data obtained by compensating at least one or none of a temporary transfer function of the optical receiver and transmission path characteristics detected in the receiver, with a first known signal before transmission to which what is not compensated for the first data between the temporary transfer function of the optical receiver and the transmission path characteristic is added.

An optical device has an optical transmitter circuit formed in a substrate, a first port configured to output an optical signal generated by the optical transmitter circuit from an edge of the substrate during services and to input a test light from the edge of the substrate during a test, and a photodetector configured to detect the test light input from the first port.

Examples described herein relate to method for measuring a disconnect response time. The method includes discontinuing, in response to a determining that a disconnect response metric test is to be initiated, transmission of a test optical signal by a test device to a DUT coupled to the test device, wherein the DUT is to discontinue transmission of a response optical signal to the test device upon detection of a loss of the test optical signal. Further, a loss of the response optical signal by may be detected by the test device. Furthermore, a disconnect response metric of the DUT may be determined by the test device based on a time of discontinuation of the transmission of the test optical signal and a time of detection of the loss of the response optical signal.

A system includes a processor communicatively coupled to an Amplifier Stimulated Emission (ASE) source and an optical receiver, wherein the processor is configured to cause transmission of one or more shaped ASE signals, from the ASE source, on an optical fiber, obtain received spectrum of the one or more shaped ASE signals from the optical receiver connected to the optical fiber, and characterize the optical fiber based in part on a nonlinear skirt and/or center dip depth in the received spectrum of the one or more shaped ASE signals. The one or more shaped ASE signals can be formed by the ASE source communicatively coupled to a Wavelength Selective Switch (WSS) that is configured to shape ASE from the ASE source to form the one or more shaped ASE signals with one or two or multiple peaks and with associated frequency.