In some examples, an optical time-domain reflectometer (OTDR)-based high reflective event measurement system may include an OTDR, and an N by M optical switch optically connected to the OTDR or disposed within the OTDR. The optical switch may include a variable attenuator mode and at least one optical fiber connected to at least one output port of the optical switch. At least one fiber optic reflector may be disposed at an end of the at least one optical fiber. A variable optical attenuator may reduce, for the at least one optical fiber including the at least one fiber optic reflector, an amplitude of reflective peaks.

In some examples, high speed bidirectional OTDR-based testing may include transmitting data from a first end of a device under test (DUT) towards an optical time-domain reflectometer (OTDR) that is operatively connected to a second opposite end of the DUT. Further data that is transmitted by the OTDR may be received from the second opposite end of the DUT towards the first end of the DUT. Based on an amplitude of the further data, a direction of receiving of the further data may be adjusted towards a first receiver or towards a second receiver.

In some examples, high speed bidirectional OTDR-based testing may include transmitting data from a first end of a device under test (DUT) towards an optical time-domain reflectometer (OTDR) that is operatively connected to a second opposite end of the DUT. Further data that is transmitted by the OTDR may be received from the second opposite end of the DUT towards the first end of the DUT. Based on an amplitude of the further data, a direction of receiving of the further data may be adjusted towards a first receiver or towards a second receiver.

System and methods of measuring nonlinear interference (NLI) on a per-span basis in an optical system with a plurality of spans are provided. The method includes steps of varying power based on phase sensitive detection method on a span under test of the plurality of spans; observing total noise, at an optical receiver, from all of the plurality of spans; and isolating noise for the span under test from the total noise based on the varying power. The optical system can be in-service with one or more traffic-carrying channels, and the varying power is small enough on the span under test which does not impact the one or more traffic-carrying channels.

A light-receiving device includes: a light guide plate of a transparent member having a first surface and a second surface as principal surfaces opposed to each other and an emission surface formed on at least one end of the transparent member; a lens sheet having lenses and is disposed opposite to the first surface; a support member that supports the lens sheet such that a distance between the principal surface of the lens sheet and the second surface is equal to the focal distance of the lenses; a directional light-guide layer that is disposed on the second surface of the light guide plate and guides, toward the emission surface, the travel direction of an optical signal entering the light guide plate; and a receiver that receives the optical signal emitted from the emission surface of the light guide plate and converts the received optical signal into an electric signal.

An optoelectronic device that includes at least one adjustable optical damping member arranged upstream of a photodetector and damps the optical radiation passing to the photodetector. The device is configured so that an electrical output of an amplifier is connected directly or indirectly to the adjustable optical damping member. An output signal of the amplifier or a control signal formed therewith drives the optical damping member, and the photodetector, the amplifier and the damping member are integrated in the same semiconductor substrate.

An optical receiver module which receives a first optical signal including a continuous signal or a burst signal includes: a variable optical attenuator which adjusts the first optical signal to output a second optical signal; a semiconductor optical amplifier which amplifies the second optical signal to output a third optical signal; and a controller which controls an output of at least one of the variable optical attenuator and the semiconductor optical amplifier so as to cause the semiconductor optical amplifier to operate in a region in which gain saturation of the semiconductor optical amplifier does not occur, on the basis of at least one of: a power obtained by suppressing an outside portion of the wavelength band of the first optical signal in the third optical signal; and a power obtained by extracting the outside portion of the wavelength band of the first optical signal in the third optical signal.

A loss-based wavelength meter includes a first photodiode configured to measure power of monochromatic light; and a loss section having a monotonic wavelength dependency, wherein a wavelength of the monochromatic light is determined based on measurements of the first photodiode after the monochromatic light has gone through the loss section. This provides a compact implementation that may be used in integrated optics devices using silicon photonics as well as other embodiments.

Techniques for improving redundancy in semiconductor-based optical communication systems are provided. For example, two or more semiconductor optical amplifiers (SOAs) may be provided in an optical repeater, and each SOA may form a respective amplification path. When failure occurs on a first SOA, a second SOA that is different from the first SOA can be selected. In one example, the selection may be based on wavelength division multiplexing (WDM), and in another example, the selection may be based on optical switching. The two or more SOAs (and other optical components) may be integrated in the same substrate package.

The invention relates to a component (10) with a photodetector (PD) and an electrical amplifier (TIA) connected to the photodetector (PD), wherein the photodetector (PD) and the amplifier (TIA) are integrated in the same semiconductor substrate (11). According to the invention, at least one adjustable optical damping member (30) is arranged in front of the photodetector (PD), which damping member damps or at least can damp optical radiation arriving at the photodetector (PD), an electrical output (A) of the amplifier (TIA) is connected directly or indirectly to the adjustable optical damping member (30) and an output signal (AS) of the amplifier (TIA) or a control signal (ST) formed therewith controls the optical damping member (30), and the photodetector (PD), the amplifier (TIA) and the damping member (30) are integrated in the same semiconductor substrate (11).