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).

To provide a means that can notify a user, of a sub-band of a wavelength-multiplexed optical signal, regarding the occurrence of a problem, a notification system comprising: a detection means that receives a wavelength-multiplexed optical signal including a plurality of optical signals, and on the basis of an intensity of an optical signal in a sub-band allocated to the wavelength-multiplexed optical signal, detects the optical intensity in the sub-band; an identification means which, on the basis of the optical intensity in the sub-band, identifies a sub-band in which a problem has occurred; and a notification means that provides notification of the occurrence of the problem to a notification destination associated with the identified sub-band.

An optical amplification apparatus includes: a light source that outputs to an optical transmission path first pump light which Raman amplifies signal light input from the optical transmission path and which is of a first wavelength band; a first detector that detects input, from the optical transmission path, of second pump light of a second wavelength band which is different from the first wavelength band; and a processor that performs safety light control on the light source in a case where the input of the second pump light is not detected.

An apparatus having input and output ports using a plurality of optical connector adapters, wherein the fiber connections can follow a specific mesh pattern has a plurality of fibers inside the apparatus. The fibers pass through at least one mandrel and are designed to produce a leakage in the transmitted light from each fiber of least −30 dBm, wherein the fiber buffer of fibers around the mandrel are partially stripped in at least one section. The apparatus also has an imaging system consisting of at least a lens, camera sensor and an optical filter are placed in proximity to the fiber striped section wherein the optical filter has spectral properties tuned or partially tuned to the operational wavelength of the network and the optical filter is placed in the light path before the camera sensor.

An optical IQ modulator (IQM) including two parallel Mach-Zehnder modulators (MZM1, MZM2) generates single sideband data signals. A control unit (18) generates additional optical single sideband pilot signals (PS1, PS2) positioned in a lower and a higher sideband respectively, and also further pilot signals (PS3, PS4) in both sidebands. A IQ modulator output signal (MOS) converted into electrical monitoring signals (MOS) and monitored. A control unit (18) selects control signals (CS12, CS3, CS4) and controls the IQ modulator via its bias ports (6, 7, 8) till the power transfer functions (PTF) of the Mach-Zehnder modulators (MZM1, MZM2) and the phase difference (ΔΦ) between their output signals is optimized.

Systems and methods include responsive to transmission of a power spectral density input into an optical system with one or more probe signals, obtaining first measurements of a performance metric of each of the one or more probe signals at an output of the optical system while the one or more probe signals are moved across a band of optical spectrum; responsive to causing power perturbations across the band, obtaining second measurements of the performance metric of each of the one or more probe signals at the output of the optical system while the one or more probe signals are moved across the band; analyzing the performance metric as a function of power utilizing the first measurements and the second measurements; and utilizing results from the analyzing to optimize the performance metric in the optical system.

There is provided an optical transmitter including a memory, a processor coupled to the memory and the processor to generate an electric signal, an optical generator to generate light, an optical modulator to modulate the light with the electric signal to create an optical signal, a first voltage electrode to apply a first voltage to the optical signal, a second voltage electrode to apply a second voltage to the optical signal to which the first voltage is applied, and a detector to detect an optical power of the optical signal to which the second voltage is applied, wherein the processor stops generating the electric signal, controls the first voltage electrode to change the first voltage after the stop of generating the electric signal, and controls the second voltage electrode to change the second voltage according to the detected optical power after the change of the first voltage.

Examples described herein relate to a method for synchronizing a wavelength of light in an optical device. In some examples, a heater voltage may be predicted for a heater disposed adjacent to the optical device in a photonic chip. The predicted heater voltage may be applied to the heater to cause a change in the wavelength of the light inside the optical device. In response to applying the heater voltage, an optical power inside the optical device may be measured. Further, a check may be performed to determine whether the measured optical power is a peak optical power. If it is determined that measured optical power is the peak optical power, the application of the predicted heater voltage to the heater may be continued.

An optical transmission device includes a reception unit that receives a first signal light and a second signal light, the first and second lights having power levels that respectively correspond to transmission distances and being transmitted; an amplification unit that amplifies the first signal light and the second signal light in accordance with a signal light having a high power level from among the received first signal light and second signal light; and a transmission unit that performs transmission of the amplified first signal light and second signal light.

A method for determining timing information in an optical communication link includes transmitting a falling edge from a transceiver positioned at a near end of the optical communication link and simultaneously starting a first timer at the transceiver positioned at the near end of the link. The transmitted falling edge is received at a transceiver positioned at a far end of the link. A falling edge is transmitted from the transceiver positioned at the far end of the link after a response delay. The transmitted falling edge is received at the transceiver positioned at the near end of the link while the first timer is simultaneously terminated at the transceiver positioned at the near end of the link and the elapsed time is recorded. The total link delay is determined based on the elapsed time.