A method of using an adjustable attenuation fiber optic wrap plug (AAFOWP) includes receiving initial data into a wireless module of the AAFOWP, wherein the initial data corresponds to an initial desired attenuation level that the first AAFOWP is to achieve. The method also includes moving, in response to receiving the initial data, an arm by an actuator to change a bend radius of an optical fiber wrap in the AAFOWP, thus adjusting an attenuation through the AAFOWP to the initial desired attenuation level.

A single-ended data transmission system transmits a signal having a signal voltage that is referenced to a power supply voltage and that swings above and below the power supply voltage. The power supply voltage is coupled to a power supply rail that also serves as a signal return path. The signal voltage is derived from two signal supply voltages generated by a pair of charge pumps that draw substantially same amount of current from a power supply.

The present application discloses an optical-fiber link routing look-up method, a fault detection method and a diagnostic system. The optical-fiber link comprises of an optical port and a routing port. Photosensitive elements are set on the optical-fiber connection point of each routing port. Detection optical wave used to generate spilled light on the optical-fiber connection point is input through optical-fiber links with different optical ports. Corresponding routing port of the optical port can be found through the spilled light detected by the photosensitive element. The photosensitive unit also includes a reminder element, which is used to produce sound and/or light when the spilled light is detected by the photosensitive element. In the disclosed diagnostic system, a photosensitive unit is placed on each connection point. Each connection point is used for optical induction and for determination of light intensity threshold to detect optical wave of the connection point on the optical port, as well as for generating sound and/or light at the site of the connection point, and for guiding the construction personnel to look-up routes. Through real-time monitoring of optical-fiber connection point, identification of optical-fiber route and detection of connection performance degradation can be achieved. Optical-fiber physical connection status can be controlled in real-time, and intelligent optical-fiber network routing management can be realized.

A light source outputs a light. A branching unit branches the light output from the light source into a first branched light and a local oscillation light. A modulator modulates the first branched light to output an optical signal. A receiver causes the local oscillation light to interfere with an optical signal to receive the optical signal. An EDFA amplifies the optical signal output from the modulator. An excitation light source outputs an excitation light exciting the EDFA to the EDFA. An optical attenuator attenuates optical power of the optical signal amplified by the EDFA. A control unit controls attenuation of the optical signal in the optical attenuator. The control unit adjusts the attenuation of the optical signal and adjusts an output of the excitation light from the excitation light source.

Photonically integrated normal incidence photodetectors (NIPDs) and associated in-plane waveguide structures optically coupled to the NIPDs can be configured to allow for both in-plane and normal-incidence detection. In photonic circuits with light-generation capabilities, such as integrated optical transceivers, the ability of the NIPDs to detect in-plane light is used, in accordance with some embodiments, to provide self-test functionality.

A method of measuring lengths of optical fibers on forward and return paths is provided in order to synchronize clocks of optical nodes connected by asymmetrical optical fiber paths. The method includes calculating, by a first optical network device, a first propagation delay of a first optical signal transmitted at a first wavelength on a first optical fiber to the first optical network device from a second optical network device and a second propagation delay of a second optical signal transmitted at a second wavelength on the first optical fiber to the first optical network device from the second optical network device. The second wavelength is different from the first wavelength. The method further includes determining, by the first optical network device, a first length of the first optical fiber based on the first propagation delay and the second propagation delay.

A fiber-optics communication component test device is provided, which includes a daughterboard, a motherboard and a connector. The daughterboard includes a controller and the controller generates a digital waveform signal (or bit signal). The motherboard includes a test area and a fiber-optics communication component is disposed in the test area. The connector is disposed on the motherboard and the daughterboard is detachably connected to the connector. The fiber-optics communication component receives the digital waveform signal via the connector to generate a light signal. The light signal is processed by a signal processing system to generate an input signal. The controller receives the input signal and generates a test result, including bit error rate, voltage amplitude and electric signal eye pattern, according to the input signal.

Examples described herein relate to determining whether a device can re-train settings of one or more components of another device. Some examples include conducting link re-training by: receiving, by a receiver in a first device, signals over a lane from a transmitter in a second device, the signals comprising a first communication identifying capability to re-train a link; transmitting, from the first device, a second communication including one or more components of a second device with capability to be adjusted and a request to modify one or more parameters of the one or more components; and receiving, at the first device, a third communication identifying a status of re-training. In some examples, the one or more components comprise an equalizer and the one or more parameters comprises at least one tap setting. In some examples, the one or more parameters comprise a precursor, main cursor or post-cursor equalization setting.

A method of testing a ribbon fiber cable is provided. The ribbon fiber cable includes optical fibers between a first end face and a second end face. End faces of the optical fibers are lined up in a single line in a line direction. The method includes: injecting light into each optical fiber at the second end face; measuring first power of the light exiting from each optical fiber at the first end face; disposing a member between the first end face and an optical sensor; injecting light into each optical fiber at the second end face; measuring second power of the light exiting from each optical fiber at the first end face; calculating a ratio of the second power to the first power; and testing an array of the optical fibers based on the ratio. Light transmittance of the member monotonically varies in the line direction.

According to examples, a fiber-optic testing source for testing a multi-fiber cable may include a laser source communicatively coupled to a plurality of optical fibers connected to a connector. The fiber-optic testing source may include at least one photodiode communicatively coupled to at least one of the plurality of optical fibers by at least one corresponding splitter to implement a communication channel between the fiber-optic testing source and a fiber-optic testing receiver. The communication channel may be operable independently from a polarity associated with the multi-fiber cable. The fiber-optic testing receiver may include a plurality of photodiodes communicatively coupled to a plurality of optical fibers. The fiber-optic testing receiver may include at least one laser source communicatively coupled to at least one of the plurality of optical fibers by at least one corresponding splitter to implement the communication channel between the fiber-optic testing receiver and a fiber-optic testing source.