Abstract: Adaptive transmission of optical signals. A dynamically adaptive optical receiver can include a receive optical subassembly (ROSA). The ROSA can include an opto-electronic transducer configured to receive an incoming optical signal from an incoming optical transmission link, circuitry for evaluating one or more properties related to the incoming optical signal, logic for comparing the one or more properties of the incoming optical signal to stored information representing threshold values, and circuitry for controlling a transmission characteristic of an outgoing optical signal based on a result of the comparison.

Abstract: A method of recovering a most likely value of each symbol transmitted through an optical communications network using a high speed optical signal. A stream of multi-bit digital samples of the optical signal is processed to generate a respective multi-bit estimate X?(n) of each transmitted symbol. A first function is applied to each symbol estimate X?(n) to generate a corresponding soft decision value {tilde over (X)}(n). Each soft decision value {tilde over (X)}(n) is processed to generate a corresponding hard decision value. {circumflex over (X)}(n) having an ideal amplitude and phase. A plurality of successive soft decision values and hard decision values are processed to determine a second function, which is applied to each soft decision value {tilde over (X)}(n) to generate a most likely symbol value {circumflex over ({circumflex over (X)}(n).

Abstract: An optical switching device is provided. The device includes an input stage (1) comprising broadcast modules (MD1-MD3) that provide duplicates of the same multiplex, an output stage (2) comprising programmable multiplexer modules (OWS1-OWS3) having inputs associated with respective broadcast modules, and an intermediate stage (3) connecting each programmable multiplexer module input that is associated with a broadcast module to an output of the associated broadcast module. Each broadcast module includes a programmable demultiplexer module (IWS1-IWS3) having a transit output (B1), and a selection output (B2) and a star coupler (SC1-SC3). The transit output (B1) is connected to a first input (C1) of the coupler and an input and an output of a processing device (RG, RG?) are respectively connected to a selection output (B2) and to a second input (C2) of the coupler.

Abstract: An arrangement is described for compensating intra-channel nonlinearities in an optical communications system which combines optical dispersion compensation with electronic pre-distortion (EPD). EPD with moderate lookup table size can effectively suppress intra-channel nonlinearities over optical transmission links incorporating optical dispersion compensation. The arrangement can be implemented for a variety of optical communications systems, including 10 Gb/s, 40 Gb/s and higher bit rate systems as well as single-channel and wavelength-division multiplexing (WDM) systems.

Abstract: An optical communication system is provided for conveying signals between multiple housing elements of a device, where respective optical detectors and optical light sources interact via a light guide associated with each communication path, where an optical signal produced by the optical light source and received by the optical detector travels a path where at least a first light redirection unit redirects the optical signal between an angle in which the optical signal travels along at least a portion of the length of the light guide, and an angle which allows the optical signal to exit the light guide. In at least some instances, the multiple housing elements correspond to at least a pair of housing elements that are incorporated as part of a communication device having a slider configuration. In some of the same or still further instances, one or more of the light redirection units are diffractive optical elements. In some instances, one or more of the light redirection units are reflectors.

Abstract: A receiver for a communications link includes a receiver module and a host receiver. These two components can be tested independently. In one embodiment, the receiver module is characterized with respect to noise and distortion. The noise performance can be determined by comparing input and output signals of the receiver module, to determine the relative noise of the receiver module. The distortion performance can be determined by comparing the distortion of input and output signals of the receiver module, using a reference host receiver that includes an equalizer. The host receiver can be tested by using a reference receiver module.

Abstract: In the case that a client signal having a bandwidth larger than BW divided by P exists, where the P is the number of client ports of one optical transponder card and the BW is an optical signal band, it is configured to accommodate client signals in one optical transponder card by combining plural client signals of which the total band is no greater than the BW and which have different bands so as to make it a maximum within the aforementioned range.

Abstract: A remote access unit (RAU) apparatus, coupled to a central station (CS) of an RoF network through at least one optical fiber, and which RAU apparatus includes at least one antenna, includes: first and second antenna ports coupled to the at least one antenna; first and second optical fiber ports coupled to the at least one optical fiber; a first coupler for decoupling a first downstream signal of a first duplexing method and a second downstream signal of a second duplexing method, which are input through the first optical fiber port; a circulator for outputting the first downstream signal input from the first coupler to the first antenna port and outputting a first upstream signal of the first duplexing method input from the first antenna port to the second optical fiber port; and a second coupler for outputting the second downstream signal input from the first coupler to the second antenna port and outputting a second upstream signal of the second duplexing method input from the second antenna port to the sec

Abstract: An optical telephone and communication system with interferometers at the transmitter and receiver can use optical time-delay difference and differential frequency shift modulation and multiplexing techniques. The power to the system is provided from either a remote optical source through the optical network or a local optical source. The optical network provides one or two optical connections to the sets. Part of the optical signal from the network is converted to electrical energy stored in a rechargeable battery. The optical sources used have a known coherence function, wavelength and coherence length Lc. The transmitter converts the information to phase variation in one arm of the transmitter interferometer and the receiver recovers this signal by using a matched interferometer. The path imbalance between the two arms of either interferometer is greater than Lc. Each set is assigned a particular time delay difference and/or differential frequency shift for addressing.

Abstract: An interactive vehicle communication system, particularly for communication between motor vehicles, comprises a communication device (2) which may be placed on a stationary support (3) or a vehicle (4) traveling on a roadway and a receiver device (5), which may be placed on a stationary support (3) or a vehicle (4?) traveling on a roadway and interacts with said communication device (2). The communication device (2) comprises first means (6) for interfacing with external data detection and/or generation means, emitter means (9) for generating and emitting a visible light-emitting laser beam (8) with predetermined solid angle (a) and range, digitizing means (7) for digitizing said laser beam (8) and control means (10) for appropriately conforming and orienting said laser beam (8), to allow it to selectively interact with vehicle driving in a predetermined drive direction, excluding the other vehicles driving in the opposite drive direction.

Abstract: An optical transmission apparatus is provided in which high optical output power is secured in an optical transmitter, the fine adjustment of the optical axis is unnecessary, and the propagation range of the optical output signal can be adaptively changed. A diffusing liquid lens includes a first liquid and a second liquid containing a scattering material that scatters light, and the curvature of the boundary surface between the first and the second liquids is changed according to the control voltage applied from a controlling unit. A first optical signal outputted from a light emitting device is diffused in the first liquid, and emitted as a second optical signal having a spread angle corresponding to the curvature of the boundary surface and a substantially uniform radiant intensity distribution.

Abstract: The present disclosure is directed to an optical transport system and device that conserves power, provides for efficient transport of photonic signals and is capable to accommodate a number of different nodes. The system and device are implemented with the major components at the nodes to provide easy maintenance. In a first aspect, the disclosure is directed to an optical transport system that provides for low power and efficient transport of photonic signals. The optical transport system can be implemented with a plurality of similar or identical network interface units that correspond with each node of the system. Also disclosed is an optical transport system architecture having an example architecture that includes a primary system and a secondary system, which is redundant to the primary system and is adapted to be operational when the primary system is inactive, or an example architecture that includes just a primary system.

Abstract: In one inventive aspect, a transmitter is provided. In the transmitter, a modulator supplies an electrical current based on a digital transmission electrical signal to a white LED, which emits light including a plurality of wavelengths into the air. A light detector separates a light signal component having a blue wavelength from the emitted light using an optical filter and converts the signal component to a monitoring electrical signal. A waveform control circuit outputs a control signal so that the time delay of the waveform of the monitoring signal with respect to the waveform of the transmission electrical signal is less than or equal to a predetermined value. The modulator corrects the amount of the electrical current supplied to the white LED on the basis of the control signal. In another inventive aspect, a receiver is provided.

Abstract: Various methods, systems, and apparatuses in which a wavelength-division-multiplexing passive-optical-network includes a first broadband light source and a second broadband light source. The first broadband light source supplies an optical signal containing a first band of wavelengths to a first plurality of optical transmitters. The second broadband light source supplies an optical signal containing a second band of wavelengths to a second plurality of optical transmitters. A fiber is used for bi-directional transmission of optical signals in at least two different wavelength bands.

Abstract: The present invention is an optical clock signal extraction device, comprising first conversion means and second conversion means for enabling to extract an optical clock signal without depending on the polarization direction of an input optical signal. The first conversion means comprises a first optical converter and a continuous wave light source of which wavelength is ?2, where an input optical signal of which wavelength is ?1 and continuous wave light of which wavelength is ?2 are input to the first optical converter, and an intermediate optical signal of which wavelength is ?2 is generated and output without depending on the polarization direction of the input optical signal. The second conversion means has a second optical converter, where the intermediate optical signal is input to the second optical converter, and an optical clock signal of which wavelength is ?3 is generated and output by the passive mode locking operation of the second optical converter.

Abstract: The invention is directed toward a variable spectral phase encoder. The variable spectral phase encoder includes a plurality of switches and at least one encoder. The encoder is coupled between a first switch and second switch among the plurality of switches. The first switch selectively routes an optical signal to some combination of fixed encoders such that their collective product applies one of the Hadamard sequences to the optical signal.

Abstract: A system and a method for quantum key distribution between a transmitter and a receiver over wavelength division multiplexing (WDM) link are disclosed. The method includes providing one or more quantum channels and one or more conventional channels over the WDM link; assigning a different wavelength to each of the one or more quantum channels and each of the one or more conventional channels; transmitting single photon signals on each of the one or more quantum channels; and transmitting data on each of the one or more conventional channels. The data comprises either conventional data or trigger signals for synchronizing the transmission of the single photon signals on the quantum channels. All channels have wavelengths around 1550 nm. The WDM link can be a 3-channel WDM link comprising two quantum channels for transmitting single photon signals and one conventional channel for transmitting conventional data or triggering signals.

Abstract: An optical transmitter includes: a modulating unit that modulates an optical signal based on an electric signal; a first detecting unit that detects a first variation width of a maximum output of the modulated optical signal; a second detecting unit that detects a second variation width of a minimum output of the modulated optical signal; a comparing unit that performs a comparison of the first variation width and the second variation width; and an adjusting unit that adjusts a bias potential of the electric signal based on a result of the comparison.

Abstract: An optical communication system which constructs, at low cost, a network that uses Time Division Multiplexing in at least one direction of the communication. The optical communication system includes an optical multiplexer/demultiplexer that mediates communication between a network unit and a plurality of terminal units. The optical multiplexer/demultiplexer regenerates a synchronization clock from a downstream signal light. In addition, the optical multiplexer/demultiplexer adjusts, using the regenerated synchronization clock, the delay times of a plurality of upstream signal lights received from the terminal units. The network unit and the terminal units do not need to control the timing of the upstream signal lights. Thus, the construction costs of the optical communication system are reduced.

Abstract: A network design that reduces the number of wavelengths needed to support communications in a Wavelength Division Multiplexing (WDM) network is disclosed. Wavelengths are reused in isolated sub-networks that do not share common network paths, allowing for the reduction in cost of the WDM equipment supporting the communications in the network.