Abstract: This disclosure describes techniques to sample electrical data streams in coherent receivers. For instance, an analog-to-digital converter (ADC) samples the received electrical data stream at a sampling rate that is nominally twice or greater than twice the symbol rate of the electrical data stream that the ADC receives. A digital filter receives the digital data stream from the ADC, and digitally filters the digital data streams to output a filtered digital electrical data stream at an effective sampling rate that is less than the sampling rate and less than twice the symbol rate, and greater than or equal to the symbol rate.

Abstract: There are provided methods and devices for determining a quality parameter characterizing an optical communication signal, the methods being performed by signal detection devices. At the transmitting end, there are obtained a signal power P1 of a first optical signal, a signal power P2 of a second optical signal, a signal power P3 of a third optical signal, optionally a signal power P4 of a fourth optical signal, and a total signal power Ps of a channel where the first, second, third and optional fourth optical signals are located. At a detection point, there are further obtained a signal power P1? of the first optical signal, a signal power P2? of the second optical signal, a signal power P3? of the third optical signal and optionally a signal power P4? of the fourth optical signal. There are then determined a signal deformation factor SDF and/or an optical signal to ASE noise ratio OSNR from the obtained signal powers.

Abstract: Hybrid dilated Benes photonic switching architectures employ an arrangement of two-by-one (2×1) photonic and two-by-two (2×2) photonic elements to enjoy improved cross-talk performance while maintaining moderate cell counts. A jumpsuit switch optical network node architecture comprising multiple stages may operate more efficiently than single stage switching fabrics, by enabling manipulation of connectivity in some stages to achieve load balancing over other stages. Specifically, a first stage of switching fabrics connected to input ports of the optical node may be manipulated to load balance incoming signals over a second stage of switching fabrics coupled to output ports of the optical node. Additionally, a third stage of switching fabrics connected to add ports of the optical node may be manipulated to load balance added optical signals over the second stage of switching fabrics.

Abstract: A coherent optical spectrum analyzer for monitoring a spectrum of a fiber link is provided. The coherent optical spectrum analyzer comprises an input connectable to the fiber link, the input being connected to a first input of a coherent detector having at least two input, the first and a second input, and an output. The coherent optical spectrum analyzer further comprises a local oscillator having an output connected to the second input of the coherent detector, wherein the output of the coherent detector is connected to a first input of a processing unit, the processing unit also being connected to an input of the local oscillator, the processing unit being configured for analyzing information from the coherent detector. The local oscillator comprises a semiconductor laser tuned by temperature to a specific wavelength and swept by changing a bias current, the local oscillator being controlled by the processing unit.

Abstract: A networked speaker system communicates using Li-Fi. The LEDs implementing the Li-Fi may also have modes in which they are used to map the walls of a room in which the speakers are located, detect the locations of speakers in the room, and detect and classify listeners in the room. Based on this, waveform analysis may be applied to input audio to establish equalization and delays that are optimal for the room geometry, speaker locations, and listener locations.

Abstract: An optical signal quality monitoring apparatus includes: a holding unit configured to hold a relational expression representing a relationship among an optical signal intensity, a noise intensity, and an optical signal-to-noise ratio and a plurality of calibration coefficients used in the relational expression; a measurement unit configured to measure an optical power of input light and a noise power in the input light; an arithmetic unit configured to calculate a plurality of optical signal-to-noise ratios, based on the optical power and the noise power measured by the measurement unit, by using the relational expression and the plurality of calibration coefficients; and a determination unit configured to select one optical signal-to-noise ratio from the plurality of optical signal-to-noise ratios, based on a magnitude relationship of the plurality of optical signal-to-noise ratios calculated by the arithmetic unit.