Abstract: Methods and systems for decoding a signal include compensating for impairments in a received signal using at least carrier phase estimation, where residual phase error remains after compensation; calculating symbol log-likelihood ratios (LLRs) for symbols in the compensated signal using Monte Carlo integration; demapping the symbols in the compensated signal using the symbol LLRs and extrinsic information from signal decoding to produce one or more estimated codewords; and decoding each estimated codeword with a decoder that generates a decoded codeword and extrinsic information.

Abstract: Systems comprising at least an encoder for receiving a binary string of a data, the encoder adapted to partition the binary string into one or more binary substrings and assign a color to each one or more substrings corresponding to a color model, a controller for converting the color into electrical pulses, a light source for emitting the electrical pulses as pulses of colored light for transmission of the pulses through a communication channel. A parallel decoder may be included. The system is preferably coupled with a data compression system for compressing or decompressing binary data via a two bit partitioning scheme and replacing same with a compression key generated by the assembly of each packet with at least a second value for transmittal using the color mechanism above.

Abstract: A transmitter module having a plurality of semiconductor laser diodes (LDs) as optical signal sources that emit optical respective optical beams with specific wavelengths different from other is disclosed. The transmitter module includes, in addition to the LDs, a driver to drive LDs in the shunt-driving configuration. Inductors through which the bias currents for the LDs are provided are mounted on the driver as interposing a spacer and a top carrier.

Abstract: There is provided an integrated laser. The integrated laser includes a semiconductor waveguide having a first section, a second section and a third section. The integrated laser further includes an active region formed on the third section of the semiconductor waveguide, the active region configured for generating light, and a coupler formed on the second section of the semiconductor waveguide, the coupler configured for coupling said light between the semiconductor waveguide and the active region. In particular, the first section comprises a multi-branch splitter having a ring structure formed between two branches of the multi-branch splitter for emission wavelength control of the integrated laser. Preferably, the multi-branch splitter is a Y-branch splitter and the ring structure is formed in a space between two branches of the Y-branch splitter. There is also provided a method of fabrication thereof, an integrated tunable laser and an integrated tunable laser system.

Abstract: A method for measuring a wavelength channel tuning time by using an optical filter that converts a change of an output wavelength of a tunable device into an optical intensity change, and a system thereof. The system for measuring a wavelength channel tuning time includes: an optical filter set configured to convert a wavelength change of an optical tunable device into an optical output intensity change; at least one or more optical electric converters configured to convert the optical output intensity change output by the optical filter set into an electric signal; and a controller configured to generate a wavelength change command applied to the tunable device, so as to calculate a wavelength channel tuning time of the tunable device by using the wavelength change command and the electric signal output by the optical electric converter.

Abstract: An optical device includes a gain medium on a substrate. The device also includes one or more laser cavities and an amplifier on the substrate. The one or more laser cavities each guides a light signal through a different region of the gain medium such that each of the light signals is amplified within the gain medium. The amplifier guides an amplified light signal through the gain medium such that the amplified light signal is amplified in the gain medium.

Abstract: A radio base station has a baseband controller coupled to a radio head by an optical wavelength division multiplexed link to pass downlink signals on a first wavelength, and uplink signals on another wavelength. A compensating delay is applied to one of the signals to compensate for a difference in transmission times between the downlink and the uplink signals. The compensating delay can be controlled according to the difference in wavelengths. By compensating for such differences in transmission times, synchronisation problems can be avoided or ameliorated, or transmission distances can be increased. This can result in more flexibility in choice of wavelengths, fiber types and fiber lengths, and greater resilience. This can enable simpler installation or configuration, or reconfiguration without needing to take care to restrict the selection of wavelengths on the WDM link or restrict the length of the link for example.

Abstract: The present invention relates to an optical communication module, which includes: a first bidirectional multiplexer; a second bidirectional multiplexer; an optical fiber for connecting the first bidirectional multiplexer and the second bidirectional multiplexer to each other; one or more first light emitting devices connecting to the first bidirectional multiplexer, and operating in a first light emitting wavelength band; one or more first light receiving devices connecting to the first bidirectional multiplexer, and operating in a first light receiving wavelength band; one or more second light receiving devices connecting to the second bidirectional multiplexer, and operating in a second light receiving wavelength band; and one or more second light emitting devices connecting to the second bidirectional multiplexer, and operating in a second light emitting wavelength band.

Abstract: The invention is directed to systems and methods for re-arranging optical spectrum utilization so that unallocated portions of the spectrum may be made contiguous. Rearrangement of optical spectrum is accomplished by moving a channel from its initial spectral location to a targeted spectral location by reserving additional spectrum for that channel that at least includes the targeted spectral location, shifting the channel to the targeted location and then collapsing the reserved spectrum around the targeted location to cover the minimal required spectrum for the channel allocation of the channel. In some cases, a secondary channel can be used as an alternate source to carry user traffic while the first channel is shifted to the targeted location.

Abstract: An optical waveguide can transmit multiple optical signals imprinted or encoded with different information, thereby increasing the waveguide's information carrying capability or bandwidth. Each optical signal can comprise multiple longitudinal modes that are energized and that are modulated substantially in unison. Thus, the photonic energy of each optical signal can be spread across a wavelength region in a substantially discrete or substantially discontinuous pattern. The respective wavelength regions of the optical signals can overlap or substantially overlay one another. Modes of one of the optical signals can be substantially interleaved, interspersed, or intermingled with modes of other optical signals. Systems at ends of the optical waveguide can feed the optical signals onto and off of the optical waveguide and discriminate the optical signals from one another. The systems can comprise ring resonators. The waveguide can support an on-chip network, such as for a multicore processor of a computer.

Abstract: A dual-polarization, 4-subcarriers orthogonal frequency division multiplexed signal carrying information bits is transmitted in an optical communication network without transmitting a corresponding pilot tone or training sequence. A receiver receives the transmitted signal and recovers information bits using a blind equalization technique and by equalizing the 4-subcarriers OFDM signal as a 25-QAM signal in time domain with a CMMA (constant multi modulus algorithm) equalization method.

Abstract: A transmitter of a binary data stream comprises: a serial/parallel converter to split the binary data stream into m different parallel bit streams, each bit stream having a rate D/m which is m times lower than the initial rate D; m first encoding modules to error-correcting encode each bit stream individually; a time-interleaver to intermix the information bits originating from different encoded bit streams; an encoder to error-correcting encode the m interleaved bit streams into p bit streams; p electro-optical modulators to modulate each of the p bit streams delivered by the interleaver by means of p optical carriers of different wavelengths; and a wavelength-division multiplexer to combine the les p optical carriers into a single optical signal.

Abstract: In an optical node, a transmitter produces an optical supervisory signal for supervising an optical network, a processor is operative to control a power level of the optical supervisory signal according to a per-wavelength power level of an optical communication signal when the optical node has no post amplifiers, and a multiplexer combines the controlled optical supervisory signal with the optical communication signal to be transmitted to another optical node located downstream.

Abstract: A method and apparatus for low-rate traffic signal transmission on Optical Transport Networks (OTN). The method includes: defining a frame format of the low-rate traffic optical channel data unit (ODU) signal for bearing the low-rate traffic signal; mapping the low-rate traffic signal to the low-rate traffic optical channel payload unit (OPU) of the low-rate traffic ODU signal, generating overhead bytes and filling the bytes in an overhead section of the low-rate traffic ODU to obtain the low-rate traffic ODU signal; multiplexing low-rate traffic ODU signals to an ODUk signal of which the rate matches the transmission rate rank of the OTN where the signal is transmitted, and transmitting the signal via the OTN. Based on this method, the invention provides an apparatus for the low-rate traffic signal transmission in the OTN as well. With this invention, the low-rate traffic signal transmission in the OTN can be implemented conveniently.

Abstract: An apparatus is provided that includes n communication channels, and m communication media interfaces, and v virtual lanes. V is a positive integer multiple of the least common multiple of m and n. An information stream is transferred into data and alignment blocks striped across all of the v virtual lanes, the blocks being communicated from the virtual lanes onto the communication channels. The blocks are received on the communication channels. Each of the communication channels transmits a different portion of the blocks striped across all of the v virtual lanes. In more particular embodiments, v>=n>=m. The communication media interfaces can be electrical and optical. Each of the communication channels can include a SerDes interface operating at least 5 Gigabits per second. Furthermore, each of the m communication media interfaces is configured to transmit a different stream of information over a single optical fiber.

Abstract: A wavelength division multiplexed optical communication system includes a plurality of optical line terminals which may be part of separate in service networks, each having a line interface and an all-optical pass-through interface including a plurality of pass-through optical ports, and each also including a plurality of local optical ports which are connectable to client equipment and an optical multiplexer/demultiplexer for multiplexing/demultiplexing optical wavelengths. The optical multiplexer/demultiplexer may include one or more stages for inputting/outputting individual wavelengths or bands of a predetermined number of wavelengths, or a combination of bands and individual wavelengths.

Abstract: An optical transceiver applicable to the coherent communication is disclosed. The optical transceiver includes a laser module, a transmitter module to output a transmitting signal by modulating a phase of an laser beam output from the laser module, and a receiver module to receive a receiving signal modulated in the phase thereof and extract data by multiplying the receiving signal with an laser beam output from the laser module.

Abstract: A channel establishment method and device are provided. The method includes: establishing a media channel between a first node and a second node, wherein the first node is the source node of the media channel, the second node is the destination node of the media channel, and the media channel passes the frequency slot matrix of the one or more intermediate nodes between the first node and the second node and the optical fiber between any two nodes; and allocating frequency spectrum to the media channel from the available frequency spectrum of the optical fiber, wherein the media channel supports at least one single signal frequency slot. The solution can address the problem of how to effectively plan and manage frequency spectrum for an introduced flexible grid technology.

Abstract: Embodiments of the present invention provide a method and an apparatus for allocating optical spectrum bandwidth resources. The method includes: first determine bandwidth of an OTUbase according to optical-layer frequency grid bandwidth and carrier spectrum efficiency; then construct an HO OTUflex according to bandwidth of customer service data and the bandwidth of the OTUbase, bandwidth of the HO OTUflex is a first integer multiple of the bandwidth of the OTUbase; map the customer service data into a payload area of the HO OTUflex and encapsulate overhead information; at last, modulate the HO OTUflex that carries the customer service data to a second integer number of optical channel carriers. The embodiments of the present invention apply to a scenario where customer service data is transported.

Abstract: A transmitter comprising a plurality of modulator and multiplexer (Mod-MUX) units, each Mod-MUX unit operating at an optical wavelength different from the other Mod-MUX units. The transmitter can additional include in each Mod-MUX unit two optical taps and three photodetectors that are configured to allow the respective Mod-MUX unit to be tuned to achieve thermal stabilization and achieve effective modulation and WDM operation across a range of temperatures. The Mod-MUX transmitter avoids the use of a frequency comb. The Mod-MUX transmitter avoids cross-modulation between different modulators for different laser signals.

Abstract: Example embodiments of the present invention relate to An optical node comprising of at least two optical degrees; a plurality of directionless add/drop ports; and at least one wavelength equalizing array, wherein the at least one wavelength equalizing array is used to both select wavelengths for each degree, and to perform directionless steering for the add/drop ports.

Abstract: An optical transmission system comprises at least one first connection point and one second connection point arranged to transmit and receive at least one channel signal transmitted via at least one optical means connecting the first connection point and the second connection, wherein each of the at least one channel signal is reversibly configurable to be transmitted in either a first direction or a second direction between the first connection point and the second connection point. A method of transmitting at least one channel signal between a first connection point and a second connection point via at least one optical media in an optical transmission system, wherein each of the at least one channel signals is reversibly configurable to be transmitted in either a first direction or a second direction between the first and the second connection points.

Abstract: A WDM-PON system configured to perform an asymmetric wavelength division multiplexing and demultiplexing is proposed. A receiving end of WDM-PON system configured to receive a light transmitted from a transmission end including a first wavelength division multiplexer/demultiplexer includes a second wavelength division multiplexer/demultiplexer configured to demultiplex the light received rom the transmission end, where the second bandwidth of wavelength division multiplexer/demultiplexer is substantially greater than that of the first wavelength division multiplexer/demultiplexer.

Abstract: Disclosed is an optical signal transmitting apparatus including: an optical carrier generator configured to generate a plurality of optical carriers and outputs the optical carriers to optical modulators corresponding to the optical carriers, respectively; a plurality of optical modulators configured to modulate the optical carriers, respectively, according to an input signal; and an optical combiner configured to couple a plurality of optical signals from the plurality of optical modulators.

Abstract: A multi-laser transmitter optical subassembly may include N number of lasers, where each laser is configured to generate an optical signal with a unique wavelength. The transmitter optical subassembly may further include a focusing lens and a filter assembly. The filter assembly may combine the optical signals into a combined signal that is received by the focusing lens. The filter assembly may include N?1 number of filters. Each of the filters may pass at least one of the optical signals and reflect at least one of the optical signals. The filters may be low pass filters, high pass filters, or a combination thereof.

Abstract: A network component comprising a generalized multiprotocol label switching (GMPLS) control plane controller configured to implement a method comprising transmitting a message to at least one adjacent control plane controller, wherein the message comprises a Type-Length-Value (TLV) indicating Routing and Wavelength Assignment (RWA) information, wherein the TLV comprises a Node Attribute TLV, a Link Set TLV, or both, and wherein the TLV further comprises at least one sub-TLV indicating additional RWA information. A method comprising communicating an open shortest path first (OSPF) link state advertisement (LSA) message comprising a TLV with at least one sub-TLV to a GMPLS control plane controller, wherein the TLV comprises a Node Attribute TLV, a Link Set TLV, or both, and wherein the TLV further comprises at least one sub-TLV indicating RWA information.

Abstract: A timing interface module installs within a rack to increase bandwidth. The timing interface module receives a reference timing signal and outputs the reference timing signal to an optical multiplexer. The optical multiplexer also receives multiple data streams of different formats, and the optical multiplexer synchronizes the multiple data streams to the reference timing signal.

Abstract: There is described an optical seismic cable (2) comprising a number of sensor units (5) spaced along the length of the cable and a number of connection units (4) spaced along the length of the cable, the cable further comprising a number of first optical fibers extending substantially continuously along the cable from one connection unit to the next, and a number of second optical fibers which each extend part-way along the cable between adjacent connection units, and wherein at each connection unit at least one first optical fiber is joined to a second optical fiber, and wherein at the sensor units sensors are joined to said second optical fibers.

Abstract: An optical network for reassigning a carrier wavelength of an optical signal may include first and second optical nodes. The first optical node may be configured to transmit an optical signal along an optical path. The first optical node may also be configured to tune a carrier wavelength of the optical signal from a first wavelength to a second wavelength, according to a continuous function, to reassign the carrier wavelength of the optical signal. The second optical node may be configured to receive the optical signal and may include a feedback loop configured to adjust a wavelength of a reference optical signal to approximate the carrier wavelength of the optical signal.

Abstract: The invention is directed to apparatus, systems and methods enabling a service provider to establish an optical demarcation point located at or within equipment controlled at least in part by a customer's domain such that the service provider's domain is able to directly control access of an optical signal to their domain.

Abstract: A receiver configured to receive wave packets encoded with data via a nonlinear channel is disclosed. The receiver includes an input configured to receive the wave packets from the non-linear channel. The receiver also includes a processor configured to generate a transfer matrix from the received wave packets and find the representation of the transfer matrix as ratios of polynomials and compute the non-linear Fourier spectrum in which the data has been embedded. The receiver may also include a demodulator configured to demodulate the non-linear Fourier spectrum to recover the data. Periodic boundary conditions may be selected. Boundary conditions may be selected based on a non-periodic vanishing signal. The received wave packets may be configured as solitons. The nonlinear channel may be an optical channel.

Abstract: A tunable laser with multiple in-line sections including sampled gratings generally includes a semiconductor laser body with a plurality of in-line laser sections configured to be driven independently to generate laser light at a wavelength within a different respective wavelength range. Sampled gratings in the respective in-line sections have the same grating period and a different sampling period to produce the different wavelengths. The wavelength of the light generated in the respective laser sections may be tuned, in response to a temperature change, to a channel wavelength within the respective wavelength range. By selectively generating light in one or more of the laser sections, one or more channel wavelengths may be selected for lasing and transmission. By using sampled gratings with the same grating period in the multiple in-line sections, the multiple section tunable laser may be fabricated more easily.

Abstract: A multi-channel transceiver using a floating frequency grid for multi-channel, optical communication is presented. Transmitter frequencies are permitted to drift, and a receiver is tuned to compensate for drifts in the transmitter frequencies.

Abstract: Optical systems for wavelength division multiplexing and wavelength division demultiplexing with a multi-core fiber, and methods of their fabrication, are disclosed. The systems include a coupling mirror with a plurality of angled surfaces that are configured to direct light to or from different cores of a multi-core fiber. In addition, the multiplexer systems can further include laser chips for generating light, while the demultiplexer systems can include photodiode arrays for detecting light from the multi-core fiber. The systems can also include a guiding structure comprising filters/micro-mirrors to direct light from the lasers or to the photodiodes.

Abstract: The present invention relates to a multiplexer/demultiplexer with a connection for inputting and/or outputting an optical signal which has signal components of different wavelengths, a carrier plate (8) with at least one wavelength-sensitive element (11), a focussing member (13) with at least two focussing elements (14, 14?) as well as a detector or signal-generator plate (1), on which at least two detectors (4) or signal generators are arranged. To achieve this object, it is proposed according to the invention that both carrier plate (8) and focussing member (13) are connected to the detector or signal-generator plate (1).

Abstract: An optical transport network based on multimode/multicore fibers includes a mode-multiplexer to multiplex independent data streams from one or more transmitters; a multimode erbium-doped fiber amplifier (MM EDFA) to compensate for MMF loss; a multimode optical add-drop multiplexer (MM OADM) to add and/or drop multimode channels in multimode networks; a multimode optical cross-connect; and a mode-demultiplexer to separate various mode streams to one or more receivers.

Abstract: There is provided an optical transmission device, the optical transmission device including a wavelength selective switch configured to select a first optical signal having a first wavelength from an input signal of wavelength division multiplexing, an optical filter circuit configured to include an optical tunable filter having a pass wavelength that is tunable to a second wavelength of a second optical signal for passing therethrough, a splitter configured to split the input signal, a split signal split by the splitter being transferred to the optical filter circuit, and a coupler configured to couple the first optical signal selected by the wavelength selective switch and the second optical signal passed through the optical filter circuit.

Abstract: Services are transmittable via a transport network by using container(s), wherein each container is adapted to transmit data with a specific bandwidth and is multiplexable, according to a dynamic multiplexing structure, to at least another container adapted to transmit data with a higher bandwidth. The network management system selects a container being adapted to transmit data with a first bandwidth out of the number of containers, determines all containers of the number of containers being adapted to transmit data with a bandwidth lower than the first bandwidth, and defines all possible termination points for each determined container. All possible termination points are defined before a service to be transmitted is selected by a user. A number of the possible termination points for each determined container is selected based on a selection scheme in order to provide the selected number of the possible termination points to the user.

Abstract: An exemplary method and apparatus are provided for high efficiency wavelength division multiplexing (WDM) optical communication systems. An optical transmitter adapted to transmit an optical signal on an optical WDM transmission channel to a corresponding optical receiver is described. The optical transmitter comprises a symbol generation unit adapted to convert input data into a sequence of data symbols at a symbol rate B; with B being a real number greater zero; an amplitude modulation unit adapted to modulate an amplitude of every Nth data symbol in a sequence derived from the sequence of data symbols, thereby creating a modulated sequence of data symbols; wherein N is an integer; wherein N>2; and a digital-to-optical converter adapted to convert a sequence derived from the modulated sequence of data symbols into an optical signal to be transmitted to the optical receiver.

Abstract: A characteristic compensation method includes obtaining compensation information when degradation of a transmission characteristic of an optical transmission path of a received light signal is compensated for by using digital signal processing with respect to an electric signal obtained by photoelectrically converting the light signal, calculating an compensation value for a characteristic compensation device that optically compensates for degradation of the transmission characteristic to start characteristic compensation, based on the compensation information with respect to the light signal, setting the compensation value in the characteristic compensation device, and switching a state in which compensation is done using the digital signal processing to a state in which compensation is done using the characteristic compensation device after the setting of the compensation value is completed.

Abstract: Disclosed is a passive optical network system using a time division multiplexing scheme. According to one exemplary embodiment, the passive optical network system includes a plurality of optical network units (ONUs); an optical line terminal (OLT) to be connected to the plurality of ONUs for communication and to transmit and receive an optical signal to and from the plurality of ONUs using a time division multiplexing (TDM) scheme, wherein each of the plurality of ONUs includes a light source that generates an optical signal with a predetermined intensity even in burst-off state; and an optical filter disposed on a receiving path of an optical receiver of the OLT to filter out an optical noise signal received from an ONU in burst-off state among the plurality of ONUs.

Abstract: A remote node, e.g., a client-side node or a service-side node, writes wavelength information into an overhead message of a packet carried by an optical signal when an optical port associated with the remote node is deployed. The overhead message explicitly identifies the wavelength channel associated with the newly deployed optical port to a hub node in a WDM optical network. The hub node identifies the new wavelength channel associated with the newly deployed optical port based on the overhead message to enable the hub node to associate the new wavelength channel with the newly deployed optical port.

Abstract: A method of determining a physical layer wavelength of a tunable optical network unit (ONU) in a time wavelength division multiplexing-passive optical network (TWDM-PON) is provided. First, a receiving wavelength of a tunable receiver is tuned to a downstream wavelength of one of a plurality of operable channels in a TWDM-PON system. Then, it is checked whether the tunable receiver maintains a state of loss of signal (LOS) for a predetermined period of time or the state of LOS is cleared. In response to a determination that the state of LOS is cleared, the ONU performs subsequent link establishment procedures in the channel, and in response to a determination that the state of LOS is maintained, the receiving wavelength of the tunable receiver is changed to a downstream wavelength of another channel.

Abstract: The multi-channel optical device includes a demultiplexer in a laser cavity. The demultiplexer is configured to demultiplex a multi-channel light beam into a plurality of channels. The demultiplexer limits the wavelengths of the channels that are output from the laser cavity. The gain element includes quantum dots as the gain medium.

Abstract: The disclosure describes implementations of an apparatus including a plurality of racks, wherein each rack houses a plurality of networking devices and each networking device includes a communication port. An optical circuit switch can be coupled to each of the plurality of communication ports in one or more of the plurality of racks, and a plurality of top-of-rack (TOR) switches can be coupled to the optical circuit switch. Other implementations are disclosed and claimed.

Abstract: A receiving-side integrated optical circuit of an optical transceiver has an optical wavelength demultiplexer to separate signal light components of the different wavelengths contained in a wavelength division multiplexed signal received from each of N links of a transmission path, a set of N optical amplifiers inserted between the transmission path and the optical wavelength demultiplexer, each optical amplifier being configured to collectively amplify the signal light components of the different wavelengths contained in the received wavelength division multiplexed signal, and a set of photo detectors arranged after the optical wavelength demultiplexer and to detect the signal light components of the different wavelengths.

Abstract: In an Optical Add-Drop Multiplexer, a drop section comprises a Wavelength Selective Switch (WSS) having at least one drop-port, the WSS being operative to couple a respective set of w (where w>1) wavelength channels from a received Wavelength Division Multiplexed (WDM) signal to each drop port. A respective 1:s power splitter is associated with each drop port. Each power splitter supplies the respective set of channels received from its drop port to each one of a corresponding set of coherent receivers. Each coherent receiver operates to receive a selected one of the respective set of channels.

Abstract: An optical communication technique transmits an optical signal at a higher bit rate using an optical transceiver interface couplable to a set of optical transmitters, each operating at a lower bit rate a plurality of channels, by demultiplexing the optical signals from the transmitters such that some of the resulting optical signals have wavelengths that are specified as center wavelengths by an optical communication standard for the lower bit rate optical transmission and the rest of the resulting optical signals have wavelengths offset from the specified center wavelengths, then multiplexing the resulting optical signals into the higher bit rate optical signal. Related optical communication techniques involve using the reciprocal method to receive the higher bit rate optical signal and to produce multiplexed optical signals at the lower bit rate.

Abstract: A method and device for compensating, within a node of an optical network, chromatic dispersion undergone by optical packets transmitted within time slots of wavelength division multiplexed channels along at least one link of the optical network, a time slot duration corresponding to the sum of a packet duration and an inter-packet gap duration. The method and device demultiplexes the wavelength division multiplexed channels into a plurality of bands, and transmits the bands, via a respective plurality of delay lines having predetermined delays, toward a respective plurality of packet add/drop structures comprising a coherent receiver.

Abstract: The methods, systems, and apparatuses described in this disclosure enable the use of pluggable optics such that two outgoing connections or two incoming connections can support the use of dual transmitter optics and/or dual receiver optics. The forward and/or reverse capacity of an optical network can be doubled using two transmitters and/or receivers operating in parallel. In embodiments, forward and/or reverse capacity of an optical network can be doubled using a double capacity transmitter or receiver that is operable to combine two or more electrical signals into a single optical signal. A pluggable can support two transmitting or two receiving optical links, and can also support a double capacity transmitting or receiving optical link.