A method for determining a maximum transmission capacity, TCAP.sub.MAX-OL, of an optical link, OL, within an optical network includes loading an optical transmission spectrum of the optical link, OL, being partially occupied by at least one data traffic carrying channel, CH, with amplified spontaneous emission, ASE, noise spectrally shaped such that the transmission performance of the optical transmission spectrum fully occupied with data traffic carrying channels, CHs, is matched. The method further includes determining the maximum transmission capacity, TCAP.sub.MAX-OL, of the optical link, OL, on the basis of measured link data transported through the optical link, OL, via the at least one data traffic carrying channel, CH.

A method of characterizing a multimode optical fiber results in a measure of estimated modal bandwidth (EMB) that is independent of the bandwidth of the light used in the characterization. The method includes propagating pulses of light along the multimode optical fiber at prescribed radial positions relative to an optical axis of the multimode optical fiber and detecting output pulses from the multimode optical fiber corresponding to the pulses of light propagated along the multimode optical fiber at the prescribed radial positions relative to the optical axis of the multimode optical fiber. An estimated modal bandwidth of the multimode optical fiber is calculated in a manner that accounts for chromatic dispersion of the multimode optical fiber.

An optical device is formed on an optical IC chip. The optical device includes: an optical device circuit; a first optical waveguide that is coupled to the a first grating coupler; a second grating coupler; a polarization rotator that is coupled to the first grating coupler; a polarization beam combiner or a polarization beam splitter that is coupled to the polarization rotator and to the second grating coupler; and a second optical waveguide that is coupled to the polarization beam combiner or to the polarization beam splitter. The first optical waveguide and the second optical waveguide respectively extend to an edge of the optical IC chip.

A test instrument measures performance of a transponder without direct access to a line interface of the transponder. The test instrument learns parameters of internal signal conversion processes of the transponder and measures performance of the transponder based on the learned parameters.

An example system includes capture circuitry to obtain first parametric data based on a first signal at an interface to a first communication channel, with the first parametric data representing non-informational content of the first signal; and control circuitry to receive the first parametric data and to provide second parametric data, the second parametric data being based on one or both of: the first parametric data or a programmatic input. The example system also includes interface circuitry to receive the second parametric data and to receive informational content data representing informational content, and to process the informational content data and the second parametric data to produce a second signal. The second signal has the informational content represented by the informational content data and having at least some non-informational content based on the second parametric data.

An optical measurement apparatus configured to measure a photonic integrated circuit (photonic IC) is provided. The optical measurement apparatus includes a substrate, at least one optical waveguide device, a first connector, and a second connector. The at least one optical waveguide device is disposed on the substrate. The first connector and the second connector are connected with the at least one optical waveguide device. An optical signal from a first optical fiber is transmitted to the at least one optical waveguide device through the first connector, transmitted to the inside of the photonic IC though at least one first evanescent coupler of the photonic IC, transmitted to the at least one optical waveguide device through at least one second evanescent coupler of the photonic IC, and transmitted to a second optical fiber through the second connector in sequence.

An optical measurement apparatus configured to measure a photonic integrated circuit (photonic IC) is provided. The optical measurement apparatus includes a substrate, at least one optical waveguide device, a first connector, and a second connector. The at least one optical waveguide device is disposed on the substrate. The first connector and the second connector are connected with the at least one optical waveguide device. An optical signal from a first optical fiber is transmitted to the at least one optical waveguide device through the first connector, transmitted to the inside of the photonic IC though at least one first evanescent coupler of the photonic IC, transmitted to the at least one optical waveguide device through at least one second evanescent coupler of the photonic IC, and transmitted to a second optical fiber through the second connector in sequence.

A measurement system is a measurement system inspecting an optical transmission line configured by connecting a plurality of optical cables, each of which includes a plurality of optical fibers, wherein the optical transmission line includes a plurality of optical fiber lines configured by connecting the plurality of optical fibers in the plurality of optical cables, the measurement system including: a first measurement device configured to be disposed at a first end of the optical transmission line; and a second measurement device configured to be disposed at a second end of the optical transmission line, wherein the first measurement device and the second measurement device perform a first measurement to inspect whether the optical cable is misconnected, and a second measurement to inspect the plurality of optical fiber lines in a case where it is determined that there is no misconnection in the first measurement.

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.

A submarine optical repeater includes a submarine amplifier module, which further includes a pumping laser module and an optical detector module. The pumping laser module generates optical amplifications within an optical cable, and, in the case of a fault in the optical cable, the optical detector module detects at least one characteristic of an optical signal caused by the fault in the optical cable. This configuration then identifies a particular signal characteristic that indicates a fault within the optical cable.