A package for optical receiver module includes a conductive housing and a feedthrough. The conductive housing includes a first sidewall having an optical port for receiving an optical signal along an optical axis, a second sidewall separated from the first sidewall along the optical axis, and an interior space for housing a photodetector. The feedthrough includes first to third layers extending from the second sidewall to an opposite direction of the first sidewall, and the third layer is provided between the first and second layers. The feedthrough includes first to fourth wirings, a grounding wiring, and a plurality of first conductive cells. The first and second wirings face the interior space. The third wirings, the fourth wiring, the grounding wiring are formed in the first layer or the second layer. The plurality of first conductive cells are arranged in the third layer, and are electrically connected to the grounding wiring.

An optical signal receivers, systems including the optical signal receivers, and methods of operating the same include a multimode fiber circulator including a first port, a second port, and a third port, a first multimode fiber cable coupled to the first port and having an input configured to receive a complex modulated optical signal and provide the complex modulated optical signal to the first port of the multimode fiber circulator, a second multimode fiber cable including a low Q optical resonator coupled to the second port of the multimode fiber circulator that is configured to receive the complex modulated optical signal from the second port of the multimode circulator, and a third multimode fiber cable coupled to the third port of the multimode fiber circulator that is configured to receive a reflected optical signal from the third port of the multimode circulator, the reflected optical signal being reflected from the low Q optical resonator.

An optical signal receivers, systems including the optical signal receivers, and methods of operating the same include a multimode fiber circulator including a first port, a second port, and a third port, a first multimode fiber cable coupled to the first port and having an input configured to receive a complex modulated optical signal and provide the complex modulated optical signal to the first port of the multimode fiber circulator, a second multimode fiber cable including a low Q optical resonator coupled to the second port of the multimode fiber circulator that is configured to receive the complex modulated optical signal from the second port of the multimode circulator, and a third multimode fiber cable coupled to the third port of the multimode fiber circulator that is configured to receive a reflected optical signal from the third port of the multimode circulator, the reflected optical signal being reflected from the low Q optical resonator.

A wavelength division multiplexing filter comprises: a first multi-order Mach-Zehnder interferometer comprising a plurality of first-order Mach-Zehnder interferometers, and a second multi-order Mach-Zehnder interferometer comprising a plurality of first-order Mach-Zehnder interferometers; wherein the first multi-order Mach-Zehnder interferometer and the second multi-order Mach-Zehnder interferometer are included in a group of multiple multi-order Mach-Zehnder interferometers arranged within a binary tree arrangement, the binary tree arrangement comprising: a first set of a plurality of multi-order Mach-Zehnder interferometers, the first set including the first multi-order Mach-Zehnder interferometer, and having an associated spectral response with a first spacing between adjacent passbands, and a second set of at least twice as many multi-order Mach-Zehnder interferometers as in the first set, the second set including the second multi-order Mach-Zehnder interferometer, and having an associated spectral response with a second spacing between adjacent passbands that is twice the first spacing.

Consistent with an aspect of the present disclosure, electrical signals or digital subcarriers are generated in a DSP based on independent input data streams. Drive signals are generated based on the digital subcarriers, and such drive signals are applied to an optical modulator, including, for example, a Mach-Zehnder modulator. The optical modulator modulates light output from a laser based on the drive signals to supply optical subcarriers corresponding to the digital subcarriers. These optical subcarriers may be received by optical receivers provided at different locations in an optical communications network, where the optical subcarrier may be processed, and the input data stream associated with such optical subcarrier is output. Accordingly, instead of providing multiple lasers and modulators, for example, data is carried by individual subcarriers output from an optical source including one laser and modulator. Thus, a cost associated with the network may be reduced. Moreover, each of the subcarriers may be detected by a corresponding one of a plurality of receivers, each of which being provided in a different location in the optical communication network. Thus, receivers need not be co-located, such that the network has improved flexibility.

Provided is an in-store dual-mode communication system in which shelves are disposed within a commercial space. A server is coupled to the Internet and/or a wide-area network and is configured to send and receive communications. Also provided are light-based messaging units that are located on and/or attached to such shelves, each: 1) having a light source, 2) receiving a communication from the server, and 3) in response to receipt of such communication, turning the light source on and off so as to broadcast a digital message that was included within such communication, as a binary-encoded digital signal corresponding to on/off states of the light source. A user device: (i) receives, via its light sensor, and then decodes the binary-encoded digital signal from a light-based messaging unit in order to obtain the digital message that corresponds to it; and also (ii) communicates with the server via its wireless interface.

A new and improved tunable optical receiver based on thermal optics and controllers for technologies that require fast wavelength channel tuning. The device entails a thermal control system in which a wavelength tunable filter, a sensor and at least two thermal actuators enables fast tuning, which are controlled by advanced algorithms. The key compositions of both parts are outlined and their main requirements are discussed

A receiver module includes an optical fiber configured to transmit a light beam, a collimating lens configured to collimate the light beam, a condensing lens configured to condense the light beam, and a light receiver including a sensor and a lens. The lens is disposed on the sensor, the lens and the sensor are connected to each other, and the sensor includes a light sensing zone. The condensing lens and the light receiver are disposed with respect to each other, and the light beam propagates sequentially through the optical fiber, the collimating lens, the condensing lens and the lens, and is incident on the sensor.

Integrated optical filter and photodetectors and methods of fabrication thereof are described herein according to the present disclosure. An example of an integrated optical filter and photodetector described herein includes a substrate, an insulator layer on the substrate, and a semiconductor layer on the insulator layer. An optical filter having a resonant cavity is formed in or on the semiconductor layer. The integrated optical filter and photodetector further includes two first metal fingers and a second metal finger interdigitated between the two first metal fingers on the semiconductor layer forming Schottky barriers. The first metal fingers are constructed from a different metal relative to the second metal finger.

An optic signal receiver is provided that comprises an optic signal detection unit an estimation unit, and a feedback control unit to provide a detector control signal. The optic signal detection unit comprises an adaptive optic module, a mode splitting module and a signal detection module, wherein the adaptive optic module is to modify a received optic input signal under control of the detector control signal into a multi-mode optic output signal, the mode splitting module is configured to branch the multi-mode optic output signal off into multiple reduced mode optic signals and the signal detection module is configured to issue a detection signal, the signal detection module comprising a plurality of signal detection sections that are each configured to measure an intensity of a respective one of the reduced mode optic signals and to provide a respective indicator indicative of the measured intensity as a component of the detection signal. The feedback control unit is configured to minimize a difference between the detection signal and a detection reference signal with the detector control signal. The estimation unit is configured to issue a further input signal to the feedback control unit based on a model of the optic signal detection unit.