Abstract: It is impossible to compensate non-linearity in an optical transmitter during operations, therefore, an optical transmitter according to an exemplary aspect of the invention includes a selective addition means for adding a coefficient to digital data to be transmitted if the digital data being included in one of data intervals of predetermined number, the predetermined number being integer more than one, and for changing the coefficient with a period longer than the symbol period of the data transmitted by the optical transmitter; a data processing means for processing the digital data by using a parameter; a driving signal means for generating a driving signal from the digital data adjusted by the selective addition means and the data processing means; a modulating means for modulating light into lightwave signal by the driving signal; and a control means for receiving a monitor signal obtained by monitoring the lightwave signal having a frequency component determined by the period of changing the added coef

Abstract: A communication system that can be used, e.g., to provide high-speed access to the servers of a data center. In an example embodiment, the communication system transports data using WDM optical signals. The downlink WDM signals have some WDM components that are modulated with data and some WDM components that are not modulated with data. The uplink WDM signals are generated at the server end of the system by modulating with data the unmodulated WDM components received through the downlink. Appropriately connected wavelength multiplexers, wavelength demultiplexers, and/or optical filters can be used to properly apply the various modulated WDM components to the corresponding optical receivers and the unmodulated WDM components to the corresponding optical transmitters. The resulting system architecture advantageously enables, e.g., the use of a single, conveniently located multi-wavelength light source to provide carrier wavelengths for both uplink and downlink optical traffic.

Abstract: In an optical communications system, the thermal pathway for dissipating heat generated by clock and data recovery (CDR) circuitry of an optical communications module is a separate from the thermal pathway that is used to dissipate heat generated by other components of the module. The CDR circuitry is external to the module and is provided with its own heat dissipation device. Keeping the CDR circuitry external to the module and providing it with its own heat dissipation device decouples the thermal pathway for dissipating heat generated by the CDR circuitry from the thermal pathways used for dissipating heat generated by other components of the module. This results in more effective heat dissipation and better component performance.

Abstract: The present invention relates to a driver system that can include an optical power based isolated power supply. The driver system can include an optical receiver that can be in communication with an optical transmitter to receive an optical signal. The optical receiver can be configured to convert the optical signal to a drive signal having a determined drive strength. The driver system can further include a driving circuit that can be configured to drive an input of the transistor device based on the drive signal according to a control signal defining an on-time and off-time for the driving circuit over a time interval. In some examples, the driver system can be integrated with a protection system.

Abstract: A multi-lane optical apparatus is disclosed. The optical apparatus includes monitor photodiodes (mPD) whose number corresponds to a number of lanes. The mPDs are arranged in an array so as to intersect optical axes of the respective lanes. The mPD has a light-sensitive area and an electrode that are arranged on a diagonal connecting two corners. The light-sensitive area is disposed offset from the center of the mPD. The mPDs in outermost are disposed such that the respective electrodes face inward.

Abstract: An optical reception apparatus (1) of the present invention includes: a local oscillator (11) outputting local oscillation light (22); an optical mixer (12) receiving a multiplexed optical signal (21) and the local oscillation light, and selectively outputting an optical signal (23) corresponding to the wavelength of the local oscillation light from the multiplexed optical signal; a photoelectric converter (13) converting the optical signal (23) output from the optical mixer into an electric signal (24); a variable gain amplifier (15) amplifying the electric signal (24) to generate an output signal (25) whose output amplitude is amplified to a certain level; a gain control signal generating circuit (16) generating a gain control signal (26) for controlling the gain of the variable gain amplifier (15); and a monitor signal generating unit (17) generating a monitor signal (27) corresponding to the power of the optical signal (23) using the gain control signal (26).

Abstract: Direct communicative coupling of a base station(s) to a remote unit for exchanging communications services with a distributed communications system (DCS) is disclosed. For example, the remote unit may include a remote antenna unit that is provided in a distributed antenna system (DAS) as one type of DCS. In this manner, the remote unit can facilitate distribution of communications services from a base station into the DCS at locations other than at a centralized location in the DCS, such as at a central unit or head-end equipment. Various DCS configurations are possible that include a remote unit supporting the direct communicatively coupling to a base station(s) for distributing communications services in a DCS.

Abstract: Embodiments of the present invention generally relate to the field of fiber optics, and more specifically to apparatuses, methods, and/or systems associated with testing fiber optic transmitters. In an embodiment, the present invention is an apparatus comprising a laser optimized multimode fiber having near minimally compliant effective modal bandwidth, near maximum channel length, and ?-profile that produces an R-MMF DMD slope.

Abstract: This application discloses a method, including: determining a transmission rate of a to-perform-sending optical network unit (ONU); generating a reset signal before the to-perform-sending ONU sends an optical signal, where the reset signal is used to trigger the OLT to perform a reset operation; adjusting a signal characteristic of the reset signal according to the transmission rate, to generate an adjusted signal; extracting a signal characteristic of the adjusted signal, and generating a first signal and a second signal according to the signal characteristic of the adjusted signal, where the first signal indicates the reset signal, and the second signal indicates the transmission rate of the to-perform-sending ONU; performing the reset operation according to the first signal; and after the reset operation is completed, adjusting the reception parameter of the optical line terminal OLT according to the second signal.

Abstract: The present invention relates to A channel set up method of optical receiver with wavelength tunable filter such as an etalon filter in a TO type received wavelength-tunable optical receiver. According to the method of setting a channel in a wavelength-tunable optical receiver of the present invention, by circularly receiving communication channels within a predetermined temperature range, in which selectively receiving communication channel using two adjacent transmissive modes in the transmissive modes of a wavelength-tunable filter, it is possible to individually select and receive all communication channels with a predetermined temperature range. Further, it is possible to use all FP type etalon filters regardless of transmissive wavelength characteristics in at a specific temperature of a wavelength-tunable filter, so it is possible to reduce a manufacturing cost and power consumption of a product and increase thermal stability of a package.

Abstract: A laser light generator is configured to generate one or more wavelengths of continuous wave laser light. The laser light generator is configured to collectively and simultaneously transmit each of the wavelengths of continuous wave laser light through an optical output of the laser light generator as a laser light supply. An optical fiber is connected to receive the laser light supply from the optical output of the laser light generator. An optical distribution network has an optical input connected to receive the laser light supply from the optical fiber. The optical distribution network is configured to transmit the laser light supply to each of one or more optical transceivers and/or optical sensors. The laser light generator is physically separate from each of the one or more optical transceivers and/or optical sensors.

Abstract: A method of local path protection in a node on a shared alternative path of a network. The method comprising receiving a signal switched on a primary label switched path (LSP). The signal is switched by lambda-switching or time-division multiplex TDM switching. The method further comprises receiving identification information arranged to identify the signal, and forwarding the signal on the alternative path based on the identification information.

Abstract: A system for optical communications may include a multiplicity of optical communications relay platforms that each move above a surface of the earth. Each relay platform may include a relay link for communications between adjacent relay platforms. The system may also include a plurality of ground stations. Each ground station may be configured to communicate with another of the ground stations through at least one of the relay platforms. Each ground station may include an optical communications link for optical communications with successive relay platforms. The optical link of each ground station may be configured for handover connections between the successive relay platforms as the relay platforms move relative to the earth. The system may additionally include a network operations center having a link controller. The link controller may be configured to control switching of the communications links for hitless transmission between the ground stations.

Abstract: A connector which serves as an optical transmitter in accordance with an embodiment of the present invention includes: a transmitting circuit configured to convert a data signal into an electric current signal, the data signal being a three-valued; and an LD configured to convert the electric current signal into an optical signal. The transmitting circuit detects, as an IDLE interval, an interval during which the data signal falls within a predetermined range that is between a high level and a low level. The transmitting circuit controls, during the IDLE interval, the electric current signal to be not greater than a threshold electric current of the LD.

Abstract: A transceiver (4) comprising a receive part (70) configured to receive and detect a first signal carried on an optical carrier, wherein the signal is in a first part of a RF spectrum. The transceiver (4) further comprises a modulator (68) configured to modulate the same optical carrier with a second signal in a second part of the RF spectrum. The transceiver comprises a transmit part (60) configured to transmit the optical carrier modulated with the second signal. The first part of the RF spectrum is separate to the second part of the RF spectrum. The first signal and/or second signal are spectrally compressed signals.

Abstract: A wet plant manager (WPM) platform is disclosed in accordance with an embodiment of the present disclosure, and supports management of Smart Undersea Network Elements (SUNEs) by providing an abstracted view of the same to higher level network management functions within an optical communication system. The optical communication system can include an optical cable system extending between two or more cable landing stations (CLSs). Each CLS may execute a respective instance of a WPM platform service, with the collective WPM platform performing self-coordination such that only one instance of a WPM service is “active” at any given time. The active WPM service supports a plurality of network topologies architected around SUNEs and “bridges” them such that requests to communicate with a particular SUNE get handled in a transparent manner without the requesters specific knowledge of which command/response (CR) telemetry path was utilized to satisfy the request.

Abstract: In general, a branching configuration used in a wavelength division multiplexed (WDM) optical communication system, consistent with the present disclosure, includes a power feed branching unit (PFBU) having a multi-port DC/DC converter (DDCM) arrangement capable of a plurality of operating modes to distribute power in a bi-directional manner. The DDCM arrangement may include a plurality of ports for electrically coupling to one or more trunk path cable segments and for electrically coupling to a branch cable segment. A plurality of PFBUs may be disposed along a trunk path, with each PFBU powering an associated branch path, without each branch path necessarily having local power feed equipment (PFE). In instances where a branch path includes a local PFE, an associated PFBU may draw power from the branch path in order to make power available to the trunk path as needed.

Abstract: A connector which serves as an optical transmitter in accordance with an embodiment of the present invention includes: a transmitting circuit configured to convert a data signal into an electric current signal, the data signal being a three-valued; and an LD configured to convert the electric current signal into an optical signal. The transmitting circuit detects, as an IDLE interval, an interval during which the data signal falls within a predetermined range that is between a high level and a low level. The transmitting circuit controls, during the IDLE interval, the electric current signal to be not greater than a threshold electric current of the LD.

Abstract: The drone-based radio-over-fiber system provides an unmanned aerial vehicle (AV), preferably a multi-rotor drone, connected to a base station by a tether including an optical fiber. A radio frequency-over-fiber system is used for bidirectional data communications between at least one radio frequency (RF) transmitter at the base station and at least one antenna mounted on the drone through the optical fiber in the tether. The system includes wave division multiplexers/demultiplexers that permit ultrahigh bandwidth communication over the tether. An embodiment of the system for 2×2 multiple-input, multiple-output (MIMO) signals in the 700 MHz LTE band is described.

Abstract: A method of fiber Kerr nonlinear noise estimation in an optical transmission system comprises recovering received symbols from a received signal, isolating a noise component of the received signal, estimating coefficients of a matrix based on cross-correlations between the isolated noise component and the fields of a triplet of received symbols or training symbols or estimated transmitted symbols, estimating doublet correlations of the product or the quotient of the isolated noise component and the field of a received symbol or of a training symbol or of an estimated transmitted symbol, and estimating one or more parameters related to nonlinear noise based on the estimated coefficients of the matrix and based on the estimated doublet correlations.