There is herein provided a method for measuring the GOSNR that can be implemented using commercial-grade transceivers and which accounts for linear optical impairments (e.g. PMD, PDL and CD) and transceiver intrinsic impairments. The method may be implemented using an Optical Spectrum Analyzer (OSA) and either the system transceivers or other commercial-grade transceivers. The proposed measurement method is based on mixed optical and electronic technologies, using an OSA and a transceiver pair. By measuring a signal quality metric Q.sub.m and the OSNR under varied power and ASE noise conditions, a constant value R.sub.BW that relates the GOSNR to the signal quality metric Q.sub.m is derived. The GOSNR is then obtained from these results.

A system (600) is disclosed comprising an optical transceiver (610) and a portable device (620). The optical transceiver comprises a laser (612) configured to generate an optical signal and a port (614) operable to transmit an optical signal generated by the laser over an optical fiber connected to the port. The portable device comprises a video camera (622) and an optical display (624). The optical transceiver (610) is configured to transmit an optical signal containing connectivity information for an optical fiber connected to the port of the optical transceiver via the optical fiber. The portable device (620) is configured to receive the optical signal transmitted via the optical fiber using the portable device video camera, and to display the connectivity information contained in the optical signal on the portable device optical display. Also disclosed are a controller (1200, 1400) for an optical transceiver, a portable device (1300, 500), and methods performed by a controller and a portable device.

A system (600) is disclosed comprising an optical transceiver (610) and a portable device (620). The optical transceiver comprises a laser (612) configured to generate an optical signal and a port (614) operable to transmit an optical signal generated by the laser over an optical fiber connected to the port. The portable device comprises a video camera (622) and an optical display (624). The optical transceiver (610) is configured to transmit an optical signal containing connectivity information for an optical fiber connected to the port of the optical transceiver via the optical fiber. The portable device (620) is configured to receive the optical signal transmitted via the optical fiber using the portable device video camera, and to display the connectivity information contained in the optical signal on the portable device optical display. Also disclosed are a controller (1200, 1400) for an optical transceiver, a portable device (1300, 500), and methods performed by a controller and a portable device.

In some embodiments, techniques for creating a design for a physical device are provided. A computing system receives an initial design of the physical device. Performance of the physical device is simulated using the initial design. A performance loss value is determined for the physical device based on the simulated performance at a target wavelength and one or more delta wavelengths. The performance loss value is backpropagated to determine a gradient corresponding to an influence of changes in the initial design on the total performance loss value. The initial design of the physical device is revised based at least in part on the gradient.

The invention is directed to the characterization of an optical channel, such as an optical fiber, in an optical network. The method includes calibrating a transmitter by measuring its transmitter and dispersion eye closure (TDEC, in the case of non-return to zero optical (NRZ) optical systems or transmitter and dispersion eye closure quaternary (TDECQ, in the case of 4-level pulse amplitude modulation (PAM4) optical systems). That calibrated transmitter is used to characterize the optical channel being tested by providing a measure of its stressed eye closure (SEC) or stressed eye closure quaternary (SECQ). A loss deficit for the optical channel can be calculated by subtracting the SEC or SECQ value from the maximum TDEC or TDECQ value.

An optical transceiver includes processing circuitry to calculate, when test signals are sent to a transmission line from a transmitter and a receiver receives the test signals having passed through a wavelength filter, a bandwidth of the received test signals, the transmitter generating, as the test signals, a collection of narrowband signals, the narrowband signals having a narrower bandwidth than a bandwidth of the wavelength filter and having different frequencies, and the wavelength filter included in an optical splitter inserted in the transmission line, and the collection of narrowband signals including a narrowband signal having a higher frequency than a highest frequency in the bandwidth of the wavelength filter and a narrowband signal having a lower frequency than a lowest frequency in the bandwidth of the wavelength filter, and to determine a modulation rate and a modulation level of the transmission signal depending on the calculated bandwidth.

An electromagnetic channel emulator system is disclosed. The system includes an electromagnetic switch matrix sub-system communicatively coupled to one or more systems under test and one or more simulation control layers. The system may include a high performance computing layer including one or more processing element nodes. The electromagnetic switch matrix sub-system may include one or more electromagnetic systems under test input/output layers and one or more high performance computing input/output layers. The one or more input/output layers may include one or more signal converters. The electromagnetic switch matrix sub-system may include one or more switches communicatively coupled to the one or more input/output layers and the high performance computing layer. The one or more switches may be configured to selectively position the one or more analog signals based on the received one or more simulation control layer signals.

An electromagnetic channel emulator system is disclosed. The system includes an electromagnetic switch matrix sub-system communicatively coupled to one or more systems under test and one or more simulation control layers. The system may include a high performance computing layer including one or more processing element nodes. The electromagnetic switch matrix sub-system may include one or more electromagnetic systems under test input/output layers and one or more high performance computing input/output layers. The one or more input/output layers may include one or more signal converters. The electromagnetic switch matrix sub-system may include one or more switches communicatively coupled to the one or more input/output layers and the high performance computing layer. The one or more switches may be configured to selectively position the one or more analog signals based on the received one or more simulation control layer signals.

This application describes techniques for testing fiber optic telecommunication systems, such as undersea fiber optic cable systems. Testing terminals may be deployed at a location of terminating equipment for a fiber optic cable. The testing terminals may be operated remotely. The testing terminals may be configured to programmatically test the cable by loading one or more tests and automatically configure the cable's transmitters and receivers based on predetermined loading schemes selected based on the tests to be performed. The testing terminals may iterate over channels and fiber pairs of the cable and may use back-to-back tests to remove artifacts from test results. Using the described techniques, a cable's channels and fiber pairs can be fully characterized in the amount of time afforded for a typical testing schedule, which was not generally possible using conventional testing.

Disclosed are an apparatus and testing methods for performing testing operations over multiple types of links and through multiple potential points of failure to segment sources of problems, which may relate to reported or actual instances of service disruption in a network communication environment. The apparatus may perform service layer testing directly via an optical link, in addition to via Ethernet service layer testing. The apparatus may further conduct tests on other layers as well, including the physical layer, the network layer, and the link layer. To facilitate efficient testing, the apparatus may integrate programmable workflow profiles that specify tests to be conducted, and may interface with a cloud platform for sharing results of the tests, providing end-to-end testing of various components and types of links (whether optical or electrical, including wired and wireless links). Results of the tests may provide guidance to resolve detected problems.