Abstract: An optical receiver is disclosed having a dielectric non-conductive substrate. A ground plane is positioned on the dielectric non-conductive substrate. An optical signal converting photodiode is also positioned on the dielectric non-conductive substrate, and has an optical signal receiver and an electrical signal output. An electrical signal amplifier is provided having an input connected to the electrical signal output of the optical signal converting photodiode. A first opening is positioned in the ground plane and surrounds the optical signal converting photodiode. The first opening has a resonance frequency higher than a fundamental frequency such that crosstalk is reducible at the input of the electrical signal amplifier.

Abstract: Methods and apparatuses, including computer program code are disclosed. The apparatus may include at least one processor and at least one memory including computer program code. The at least one processor, the at least one memory, and the computer program code may be configured to cause the apparatus to generate a divergent beam for an optical source that is coincident with a divergent beam for an optical detector. The apparatus may determine an adjustment to a mirror to cause an optical alignment of an incoming beam with the optical detector based on at least an optical intensity across the optical detector, wherein the alignment is with respect to at least another apparatus. The apparatus may adjust a position of the mirror according to the determined adjustment, and change the divergent beam to a collimated beam to enable optical communications with the other apparatus via the collimated beam.

Abstract: A system for transmitting and receiving electromagnetic radiation includes a beam splitter and a transceiver. The beam splitter is configured to separate an optical pulse into a pump pulse and a probe pulse. The transceiver may include a transmitter switch and a receiver switch. The pump pulse is directed toward the transmitter switch and the probe pulse is directed towards the receiver switch. Electromagnetic radiation is emitted from the transceiver when the pump pulse strikes the transmitter switch. The electromagnetic radiation may be terahertz radiation in either a pulsed or continuous wave form.

Abstract: In one embodiment, each of the output/input ports of each one of a plurality of optical splitters is connected to one of a plurality of optical switches by means of optical fibers without any fusion splicing in a majority of the optical fibers, and each of the input/output ports of each one of the switches is connected to one of the optical splitters by means of the optical fibers without any fusion splicing in a majority of the optical fibers. Each of the output/input ports of each one of the optical splitters may be directly connected to the ferrule and one of the input/output ports of one of the switches by the optical fibers. The optical splitters may be implemented in at least one planar lightwave circuit (PLC) chip. Optionally, at least one fiber holder defining a plurality of channels therein may be used to hold the optical fibers each of which is aligned with a corresponding output/input port of one of the optical splitters.

Abstract: A satellite in low-Earth orbit (LEO) or medium-Earth orbit (MEO) with a modern image sensor and/or other remote sensing device can collect data at rates of 10 Mbps or higher. At these collection rates, the satellite can accumulate more data between its passes over a given ground station than it can transmit to the ground station in a single pass using radio-frequency (RF) communications. Put differently, the sensors fill the spacecraft's memory faster than the spacecraft can empty it. Fortunately, free-space optical communications signals can carry far more data than RF communications signals. In particular, a spacecraft can transmit over 1 Tb of data in a single pass using burst wavelength-division multiplexed (WDM) optical signals. Each burst may last seconds to minutes, and can include tens to hundreds of WDM channels, each of which is modulated at 10 Gbps or more.

Abstract: This disclosure provides systems, methods, and apparatus for mitigating the effects of interference signals on optical signals received at a direct-detection optical receivers. The optical receivers are capable of attenuating interference noise signals resulting from the interference between a transmitted optical signal transmitted from a transmitter to the optical receiver and one or more additional signals received at the optical receiver. The interference can be due to multi-path interference or due to in-band interference. The receivers include a tunable filter for filtering the received optical signal to remove the interference. A frequency offset module processes the received optical signal to determine a frequency offset indicative of the difference between the carrier frequencies of a modulated optical signal and an interference optical signal.

Abstract: A distributed antenna system, comprising: master unit configured to: receive MIMO channel signals at MIMO frequency from signal source, MIMO channel signals including first and second MIMO channel signals; generate LO signal; frequency convert first and/or second MIMO channel signal from MIMO frequency to different frequency close to first legacy service frequency band using the LO signal; combine first MIMO channel signal, second MIMO channel signal, and LO signal for transmission; optical link operably coupled with master unit; unit communicatively coupled with master unit via optical link for transceiving first second MIMO channel signal, unit including band processing circuitry configured to process first and second MIMO channel signal; conversion circuitry configured to receive converted MIMO channel signal and to frequency convert converted MIMO channel signal from frequency close to first legacy service frequency band back to MIMO frequency for transmission over antenna.

Abstract: Embodiments of the present disclosure disclose a coherent receiver, including: a frequency offset estimation unit and a frequency offset compensation unit, where the frequency offset estimation unit is configured to receive signal light and local oscillator light, where the signal light is received by a first photoelectric detector, and a first intensity value is obtained, the signal light is received by a second photoelectric detector, and a second intensity value is obtained, the local oscillator light is received by a third photoelectric detector, and a third intensity value is obtained, and the local oscillator light is received by a fourth photoelectric detector, and a fourth intensity value is obtained; and the frequency offset compensation unit is configured to obtain a frequency offset value between the signal light and the local oscillator light according to a difference between a first ratio and a second ratio.

Abstract: This disclosure relates to wavelength division multiplexed (WDM) passive optical networks (PON), and the transmission of point-to-point and broadcast or multicast channels from an optical line transmitter (OLT) to an optical network unit (ONU).

Abstract: Methods and systems for a polarization immune wavelength division multiplexing demultiplexer are disclosed and may include, in an optoelectronic transceiver having an input coupler, a demultiplexer, and an amplitude scrambler: receiving input optical signals via the input coupler, communicating the input optical signals to the amplitude scrambler via waveguides, configuring the average optical power in each of the waveguides utilizing the amplitude scrambler, and demultiplexing the optical signals utilizing the demultiplexer. The amplitude scrambler may include phase modulators and a coupling section. The phase modulators may include sections of P-N junctions in the two waveguides. The demultiplexer may include a Mach-Zehnder Interferometer. The demultiplexed signals may be received utilizing photodetectors. The input coupler may include a polarization splitting grating coupler.

Abstract: Methods, systems, and apparatus for restricting use of a network element outside an authorized location range are disclosed. In one aspect a method includes obtaining, for a network element of a passive optical network, an identifier and ranging information corresponding to a present location of the network element; identifying, from a database and based on the identifier of the network element, stored ranging information specifying a previous location of the network element; determining, based on a comparison of the ranging information with the stored ranging information, that the location of the network element has changed more than a specified amount; and outputting an alert in response to determining that the location of the network element has changed more than a specified amount.

Abstract: In a method for communicating between a first communication device of a magnetic resonance apparatus and a second communication device, in particular one that is mobile and on the patient side, of the magnetic resonance apparatus, a communication technology using visible light is used as the transmission medium for transmission of a useful signal from at least one of the communication devices to the other communication device, in particular from the first communication device to the second communication device.

Abstract: A device and a method for synchronizing entanglement sources with optical pump in a quantum communication network are disclosed. The device includes a pulsed optical source allowing emission of telecom wavelength optical clock pulses distributed in parallel to the entanglement sources to ensure synchronization of the entanglement sources; and for each of the entanglement sources, a frequency conversion device, allowing frequency conversion of the distributed telecom wavelength optical clock pulses to a wavelength adapted to optically pump the entanglement source. The method includes emitting and distributing in parallel, to the entanglement sources, telecom wavelength optical clock pulses; and locally, at each of the entanglement sources, frequency converting the telecom wavelength optical clock pulses to a wavelength adapted to optically pump the entanglement source.

Abstract: A laser jammer configured for being a part of a countermeasure system. The system comprises a stage having an axis of rotation and laser source mounted on the stage. The laser source is configured for emitting a laser beam having an optical axis perpendicular to the axis of rotation. The laser has a first spread in a first plane parallel to the rotation axis of the stage and including the optical axis, and a second spread in a second plane perpendicular to the first plane and including the optical axis. The first spread is greater than the second spread.

Abstract: An assembly of waveguide wavelength multiplexers and demultiplexers, together with continuous wave (CW) laser transmitters that interface to grating couplers on a silicon photonics chip, providing CW sources, multiplexed output and optionally multiplexed input, all using a single photonic lightwave circuit (PLC).

Abstract: Disclosed herein are methods, structures, and devices that provide multi-range frequency domain compensation of chromatic dispersion within optical transmission systems that offer significant operational power savings. More specifically, a method of operating frequency domain filtering structures and circuits including FFT, frequency-domain filter multiplication and iFFT functions at a lower duty cycle for shorter overlap such that significant power savings is realized.

Abstract: The present invention provides an optical signal processing device and a decoding method for an optical signal reception control device. The optical signal processing device includes one of the following: a power control apparatus, where the power control apparatus is configured to control power-on and power-off of a power supply according to an optical signal, or, a clock apparatus, where the clock apparatus is configured to store time of opening and closing a door; or, a charging apparatus, where the charging apparatus is configured to charge an optical signal transmitting apparatus. The present invention can control power-on and power-off of a power supply automatically and save electric energy effectively.

Abstract: The physical layer of an optical line terminal (OLT) of an optical network is split across multiple fibers so that the OLT has a plurality of optical transceivers for respectively communicating across a plurality of optical fibers. Thus, each optical transceiver is in communication with a smaller number of optical network units (ONUs) relative to an embodiment for which a single optical transceiver is employed, thereby reducing the transmit power requirements of the optical network. Accordingly, less expensive optical components, such as lasers, can be used at the OLT and the ONUs. In addition, the split at the OLT is implemented digitally, and the digital components of the OLT are arranged such that various performance benefits are realized. As an example, the OLT may be configured such that data and/or overhead may be simultaneously transmitted in the upstream direction thereby increasing the upstream throughput and capacity of the optical network.

Abstract: An optical device may include a modulator. The modulator may receive an optical signal. The modulator may modulate the optical signal to include a first channel and a second channel. The modulator may modulate the optical signal based on a training pattern associated with detecting a skew. The modulator may cause the first channel to interfere with the second channel. The modulator may perform a power measurement on the first channel and the second channel. The modulator may determine the skew based on the power measurement and the training pattern. The modulator may time delay the first channel or the second channel to align the skew based on the skew.

Abstract: An optical transmission apparatus includes an amplifier array device; and a switch device coupled to the amplifier array device via an optical cable, wherein the amplifier array device includes a plurality of amplifiers configured to amplify a plurality of optical signals at mutually different wavelengths and to output the plurality of amplified optical signals, a plurality of beam separators configured to generate a plurality of separated light beams by separating the plurality of amplified optical signals and to output the plurality of separated light beams, a beam combiner configured to generate combined light by combining the plurality of separated light beams and to output the combined light to the switch device through the optical cable, and a photo-detector configured to detect a power of the combined light returned from the switch device through the optical cable.