An optical splitter includes a housing, a diffraction grating, and an optical filter. An incidence unit and an emission unit are provided in the housing. The optical filter is disposed between the emission unit and the diffraction grating in the housing. An anti-reflection coating is formed on a surface of a filter main body of the optical filter on the emission unit side. Therefore, from light dispersed by the diffraction grating and having passed through the optical filter, light reflected at a back surface of the emission unit passes through the optical filter without being reflected by a back surface of the optical filter and is directed toward the inside of the housing. As a result, light having passed through the optical filter and having a wavelength other than a target wavelength is inhibited from being emitted from an emission slit of the emission unit.

Integrated optical component combine the functions of a Variable Optical Attenuator (VOA), a tap coupler, and a photo-detector, reducing the size, cost, and complexity of these functions. In other embodiments, the integrated optical component combines the functions of an optical switch, a tap coupler, and a photo-detector. A rotatable mirror is used to adjust the coupling of light from an input port or ports to one or more output ports. A pin hole with a surrounding reflective surface is used at the core end face of one or more output fibers, such that a portion of the output optical signal is reflected to a photodiode chip. The photo-detector provides an indication of the optical power that is being coupled to the output fiber. With appropriate electronic control circuitry, the integrated optical component can be used to set the output optical power at a desired or required level.

A tunable filter device includes a wavelength dependent splitter; a tuning element that tunes a characteristic wavelength of the wavelength dependent splitter to a wavelength of an optical signal; and a first optical coupler that splits the optical signal into an input optical signal input to the wavelength dependent splitter and a reference optical signal, where a first output outputs a band stop filtered portion and a second output outputs a band pass filtered portion of the input optical signal. The device further includes a second optical coupler that combines the reference optical signal with the band stopped filtered portion to provide a coupled optical signal; a photodiode that provides at a photocurrent indicating a difference between the wavelength of the optical signal and the characteristic wavelength; and a control loop that provides a control signal for automatically tuning the characteristic wavelength based at least in part on the photocurrent.

Described are various configurations of reduced crosstalk optical switches. Various embodiments can reduce or entirely eliminate crosstalk using a coupler that has a power-splitting ratio that compensates for amplitude imbalance caused by phase modulator attenuation. Some embodiments implement a plurality of phase modulators and couplers as part of a dilated switch network to increase overall bandwidth and further reduce potential for crosstalk.

A photonic device such as a polarization controller includes a coupler, such as a 22 MMI coupler, or a series of such couplers. Couplers may be interspersed with other components such as phase shifters. Photodetectors such as photodiodes are coupled to input and output lines of the coupler or couplers, for example via taps. In various embodiments, all of the couplers include photodetectors monitoring light power for at least two of their inputs and outputs, and at least one of the couplers includes photodetectors monitoring at least three of its inputs and outputs. The arrangement of photodetectors can provide sufficient information for feedback control of the photonic device and/or determining the state of polarization of light within the photonic device. Signals from some photodetectors can be used to estimate light power at locations in the photonic device lacking photodetectors.

An optoelectronic device (20, 50) includes a planar substrate (30), an optical bus (40, 82, 84, 96, 140, 150, 180, 182, 224) disposed on the substrate and configured to convey coherent radiation through the bus, and an array (32, 72) of sensing cells (34, 74, 90, 160, 170, 200, 212, 380) disposed on the substrate. Each sensing cell includes at least one tap (92, 94, 144, 146, 226, 228) coupled to extract a portion of the coherent radiation propagating through the optical bus, an optical transducer (36, 108, 162, 172, 202, 204, 214) configured to couple optical radiation between the sensing cell and a target external to the substrate, and a receiver (114, 174, 178, 216, 218), which is coupled to mix the coherent radiation extracted by the tap with the optical radiation received by the optical transducer and to output an electrical signal responsively to the mixed radiation.

A method and system for data conversion includes an analog noise generator to generate a random, non-deterministic, analog noise signal. An adder adds the analog noise signal to an analog RF signal to produce a dithered analog signal. A first quantizer converts the analog noise signal to digital to produce a digital noise signal. A second quantizer converts the dithered analog signal to a digital equivalent signal. A digital dither adjustment module removes amplitude measurements of the digital noise signal from the digital equivalent signal to obtain a linearized digital representation of the analog RF signal.

A signal monitoring method and apparatus for a wavelength selective switch (WSS) are provided. The signal monitoring method for a wavelength selective switch WSS includes: encoding a phase of a first optical engine based on an input WDM signal, so that the WDM signal is split into a transmitted signal and a monitored signal after passing through the first optical engine; inputting the monitored signal to a second optical engine disposed at an output-side grating; and controlling the second optical engine to rotate in a wavelength plane of the WDM signal, so that monitored light of a specified wavelength in the monitored signal is output from the second optical engine at a preset angle.

An optical circuit switch includes a fiber hole array, a plurality of internal optical fibers, a collimating lens array, a MEMS mirror array, and a reflective surface. The fiber hole array includes an array of receptacles shaped to accept respective internal optical fibers. The collimating lens array is positioned adjacent to the fiber hole array. Each collimator of the collimating lens array optically couples light into or out of a corresponding one of the internal optical fibers. The fiber hole array, the collimator, the MEMS mirror array and the reflective surface are positioned relative to one another such that light exiting each of the internal optical fibers passes through its corresponding collimator and is redirected by a first mirror within the MEMS array towards the reflective surface, which directs the light back towards a second mirror of the MEMS mirror array, which in turn redirects the light towards a second internal optical fiber.

A method and system for data conversion includes an analog noise generator to generate a random, non-deterministic, analog noise signal. An adder adds the analog noise signal to an analog RF signal to produce a dithered analog signal. A first quantizer converts the analog noise signal to digital to produce a digital noise signal. A second quantizer converts the dithered analog signal to a digital equivalent signal. A digital dither adjustment module removes amplitude measurements of the digital noise signal from the digital equivalent signal to obtain a linearized digital representation of the analog RF signal.