The invention relates to an optical light guiding system, comprising an interface for coupling in and/or an interface for decoupling data and at least one data channel for transmitting data, and a method for transmitting data in optical systems, comprising the steps of coupling data into an interface of a beam guidance element; the transmission of the data by means of a first and/or a second data channel, which are arranged within the beam guiding element (or the casing), wherein the data channels can also be used for the fractional monitoring of the beam guiding element; and decoupling the data from an interface.

A first resistor connected in parallel to a semiconductor optical modulator having first ends, the first resistor and first ends connected to a reference potential. A first end of a first transmission line is connected to second ends of the semiconductor optical modulator and the first resistor. A second transmission line is connected in series to the first transmission line and has an impedance lower than that of the first resistor. A first end of the second transmission line is connected to a second end of the first transmission line. A third transmission line is connected in series to the first and second transmission lines and has an end connected to a second end of the second transmission line, and has an impedance equal to that of the first transmission line. A second resistor and a capacitor are connected in series between the third transmission line and the reference potential.

If a configuration is employed in which modulation schemes used for an optical communication system can be switched depending on transmission conditions, the power consumption increases and the control becomes complex; therefore, an optical transmitter according to an exemplary aspect of the present invention includes an encoding means for encoding digital signals to be transmitted under a predetermined transmission condition over an optical carrier wave by using one of a plurality of encoding methods; an encoding control means for selecting a predetermined encoding method corresponding to the predetermined transmission condition from among the plurality of encoding methods and causing the encoding means to operate in accordance with the predetermined encoding method; a mapping means for mapping output bit signals output from the encoding means to modulation symbols; and an optical modulation means for modulating the optical carrier wave based on symbol signals output from the mapping means.

An optical-frequency shift device to shift a first optical-signal of a first optical-frequency to a second optical-signal of a second optical-frequency, including a splitter to split the first optical-signal to optical-signals of first and second polarizations, orthogonal each other, a generator to generate first and fourth controlled-light of the first polarization, and second and third controlled-light of the second polarization, each of frequency differences between the first and second controlled-light and between the third and fourth controlled-light having a spacing equal to a difference between the first and second optical-frequencies, a nonlinear optical-medium in which idler light of the second and first polarization are created by causing cross phase modulation of the optical-signals of the first and second polarizations, the first and third controlled-light, and the second and fourth controlled-light, respectively, and an optical-combiner to combine the idler light of the second and first polarization.

A ferrule-less optical interconnect includes electrical communications assembly having a receptacle disposed in a housing, the receptacle adapted to mate with an electrical connector to produce a free space gap, and active optical communications components disposed in the housing and adapted to process a free space optical beam traveling along a first optical beam path through the free space gap. The free space optical beam has a substantially parallel shape and Gaussian power density distribution. Active optical components may include a light source and a collimator adapted to produce the free space optical beam. Active optical components may include a condenser adapted to receive the free space optical beam and produce a focused optical beam signal for reception by a sensor. A hole is disposed in the housing along the first optical beam path providing free space passageway between the active optical communications components and the free space gap.

A method and apparatus for synchronizing nodes in a communication network. A such as an EPoC, PON, or EPoC/PON hybrid access network. The network node receives or originates a ToD value and calculates future ToD value for a second node, which the first node includes in a ToD message for sending to the second node. The ToD message preferably includes a correction based on an OFDM ranging delay value and an adjustment based on a total transmit/receive PHY path asymmetry value with respect to the two nodes. A similar future ToD message is preferably sent to each downstream node that the first node is serving.

A system for converting digital data into a modulated optical signal, comprises an electrically controllable device having M actuating electrodes. The device provides an optical signal that is modulated in response to binary voltages applied to the actuating electrodes. The system also comprises a digital-to-digital converter that provides a mapping of input data words to binary actuation vectors of M bits and supplies the binary actuation vectors as M bits of binary actuation voltages to the M actuating electrodes, where M is larger than the number of bits in each input data word. The digital-to-digital converter is enabled to map each digital input data word to a binary actuation vector by selecting a binary actuation vector from a subset of binary actuation vectors available to represent each of the input data words.

A multiplexed sensor system includes a control unit in communication with a plurality of sensors. A plurality of optic fibers defines a communication path between the plurality of sensors and the control unit. A multiplexing portion communicates with a plurality of sensors along a common one of the plurality of optic fibers and a protected channel through which at least a portion of the optic fibers are routed. The protected channel at least partially surrounds the optic fibers and shields the optic fibers from an environment outside the protected channel. A cooling flow is provided through the protective channel for minimizing temperature fluctuations within the protective channel. A method is also disclosed.

A method and a device for determining a location of an optical splitter are provided. With the method, optical network units in a PON network are classified into K clusters based on locations of the optical network units with a K-means clustering-based algorithm. Distances between multiple optical network units in the same cluster are small. If it is determined that the number of the optical network units in each of the clusters does not exceed a threshold, a central office is added into the K clusters to obtain K new clusters; and for each of the new clusters, a location of an optical splitter corresponding to the new cluster is determined, so as to ensure that a sum of distances between the location of the optical splitter and locations of all elements in the new cluster is minimized.

An electro-optic transceiver module, method of manufacturing, and method of transmitting signals are provided that allow multiple optical signals at different wavelengths (e.g., according to CWDM) to be combined for transmission via a number of optical fibers that is smaller than the number of electrical channels according to which the optical signals were generated. Thus, CWDM may be used in connection with lower-cost VCSEL technology (e.g., as opposed to higher-cost edge-emitting lasers) by providing for wavelength compensation at the VCSEL driver to offset any changes in wavelength that may have otherwise occurred at the VCSELs. In particular, a microcontroller of the electro-optic transceiver module correlates a monitored temperature of the VCSELs to an actual wavelength of the corresponding optical signals transmitted by the respective VCSELS and determined an adjustment in a current supplied by the VCSEL driver to each VCSEL to achieve more precise and consistent wavelengths at the VCSELs.