Abstract: At a controller of an optical module including optical transmitters and optical receivers coupled to the controller and coupled to first and second optical fibers: responsive to a first command, first configuring the optical module to operate in a normal mode in which the optical module operates at a maximum communication capacity by transmitting and receiving a maximum number of wavelengths, that the optical module is capable of transmitting and receiving, on each of the first optical fiber and the second optical fiber; and responsive to a second command, second configuring the optical module to operate in a backward compatible legacy mode in which the optical module operates at a reduced communication capacity compatible with a legacy optical module by transmitting and receiving a reduced number of wavelengths, that is less than the maximum number of wavelengths, on each of the first optical fiber and the second optical fiber.

Abstract: In one embodiment, a module for plugging into a QSFP-DD (Quad Small Form Factor Pluggable Double Density) cage is provided that has one or more projections for contacting a QSFP-DD optical module in an adjacent QSFP-DD recess of the QSFP-DD cage so as to evacuate heat from, and or provide power to, the QSFP-DD optical module.

Abstract: Presented herein are a submount architecture for an electro-optical engine, which may be embodied as an apparatus in the form of at least an electro-optical engine and a multimode node, and a method for providing the same. According to at least one example, an apparatus includes a printed circuit board (PCB), a substrate with a finer structuring than the PCB, and electro-optical components. A bottom surface of the substrate is coupled to the PCB and electro-optical components are mounted on or in a top surface of the substrate. The electro-optical components include one or more optical components arranged to emit optical signals towards and/or receive optical signals from an area above the top surface of the substrate.

Abstract: Presented herein are a submount architecture for an electro-optical engine, which may be embodied as an apparatus in the form of at least an electro-optical engine and a multimode node, and a method for providing the same. According to at least one example, an apparatus includes a printed circuit board (PCB), a substrate with a finer structuring than the PCB, and electro-optical components. A bottom surface of the substrate is coupled to the PCB and electro-optical components are mounted on a top surface of the substrate. The electro-optical components include one or more optical components arranged to emit optical signals towards and/or receive optical signals from an area above the top surface of the substrate.

Abstract: In one embodiment, a pluggable module for insertion into a socket of a network cabinet is disclosed, the pluggable module comprising a body having first and second portions arranged along an axis, wherein the module is arranged for insertion of the first portion into said socket in a direction of insertion along the axis, whereupon the second portion protrudes from said socket along the axis and away from the direction of insertion, and wherein the second portion comprises a first heat sink on a surface of the second portion, wherein the first heat sink comprises a plurality of parallel fins aligned with the axis of insertion.

Abstract: In one embodiment, a module for plugging into a QSFP-DD (Quad Small Form Factor Pluggable Double Density) cage is provided that has one or more projections for contacting a QSFP-DD optical module in an adjacent QSFP-DD recess of the QSFP-DD cage so as to evacuate heat from, and or provide power to, the QSFP-DD optical module.

Abstract: In one embodiment, a module for plugging into a QSFP-DD (Quad Small Form Factor Pluggable Double Density) cage is provided that has one or more projections for contacting a QSFP-DD optical module in an adjacent QSFP-DD recess of the QSFP-DD cage so as to evacuate heat from, and or provide power to, the QSFP-DD optical module.

Abstract: In one embodiment, a module for plugging into a QSFP-DD (Quad Small Form Factor Pluggable Double Density) cage is provided that has one or more projections for contacting a QSFP-DD optical module in an adjacent QSFP-DD recess of the QSFP-DD cage so as to evacuate heat from, and or provide power to, the QSFP-DD optical module.

Abstract: In one embodiment, a pluggable module for insertion into a socket of a network cabinet is disclosed, the pluggable module comprising a body having first and second portions arranged along an axis, wherein the module is arranged for insertion of the first portion into said socket in a direction of insertion along the axis, whereupon the second portion protrudes from said socket along the axis and away from the direction of insertion, and wherein the second portion comprises a first heat sink on a surface of the second portion, wherein the first heat sink comprises a plurality of parallel fins aligned with the axis of insertion.

Abstract: An optical signal is received at a coherent optical receiver. The received optical signal is converted to a first electrical signal and a second electrical signal through a first photodetector and a second photodetector, respectively. The first electrical signal is input into a first single input variable gain amplifier, and the second electrical signal is input into a second single input variable gain amplifier. A gain of at least one of the first single input variable gain amplifier or the second single input variable gain amplifier is controlled to balance the output of the first single input variable gain amplifier and the output of the second single input variable gain amplifier. The output of the first single input variable gain amplifier and the output of the second single input variable gain amplifier are input into a differential amplifier. A receiver output is obtained at an output of the differential amplifier.

Abstract: A method for transmitting a coherent optical data signal includes receiving a data signal from an interface, and encoding the data signal with a forward error correcting (FEC) encoder according to a mix of modulation formats. The FEC encoder generates an FEC encoded signal which is used to generate modulation symbols according to the modulation formats. The FEC encoded signal of modulation symbols is spectrally shaped to generate a shaped signal, and pre-distorted before transmission. The shaped signal is pre-distorted by adding a predetermined amount of chromatic dispersion to generate a smoothed signal, and the smoothed signal is transmitted according to the modulation formats.

Abstract: An optical signal is received at a coherent optical receiver. The received optical signal is converted to a first electrical signal and a second electrical signal through a first photodetector and a second photodetector, respectively. The first electrical signal is input into a first single input variable gain amplifier, and the second electrical signal is input into a second single input variable gain amplifier. A gain of at least one of the first single input variable gain amplifier or the second single input variable gain amplifier is controlled to balance the output of the first single input variable gain amplifier and the output of the second single input variable gain amplifier. The output of the first single input variable gain amplifier and the output of the second single input variable gain amplifier are input into a differential amplifier. A receiver output is obtained at an output of the differential amplifier.

Abstract: A method for transmitting a coherent optical data signal includes receiving a data signal from an interface, and encoding the data signal with a forward error correcting (FEC) encoder according to a mix of modulation formats. The FEC encoder generates an FEC encoded signal which is used to generate modulation symbols according to the modulation formats. The FEC encoded signal of modulation symbols is spectrally shaped to generate a shaped signal, and pre-distorted before transmission. The shaped signal is pre-distorted by adding a predetermined amount of chromatic dispersion to generate a smoothed signal, and the smoothed signal is transmitted according to the modulation formats.

Abstract: An optical signal is received at a coherent optical receiver. The received optical signal is converted to a first electrical signal and a second electrical signal through a first photodetector and a second photodetector, respectively. The first electrical signal is input into a first single input variable gain amplifier, and the second electrical signal is input into a second single input variable gain amplifier. A gain of at least one of the first single input variable gain amplifier or the second single input variable gain amplifier is controlled to balance the output of the first single input variable gain amplifier and the output of the second single input variable gain amplifier. The output of the first single input variable gain amplifier and the output of the second single input variable gain amplifier are input into a differential amplifier. A receiver output is obtained at an output of the differential amplifier.

Abstract: A system configured to maintain a consistent local-oscillator-power-to-primary-signal-power ratio (LO/SIG ratio).

Abstract: An optical signal is received at a coherent optical receiver. The received optical signal is converted to a first electrical signal and a second electrical signal through a first photodetector and a second photodetector, respectively. The first electrical signal is input into a first single input variable gain amplifier, and the second electrical signal is input into a second single input variable gain amplifier. A gain of at least one of the first single input variable gain amplifier or the second single input variable gain amplifier is controlled to balance the output of the first single input variable gain amplifier and the output of the second single input variable gain amplifier. The output of the first single input variable gain amplifier and the output of the second single input variable gain amplifier are input into a differential amplifier. A receiver output is obtained at an output of the differential amplifier.

Abstract: Using polarization modulation techniques to simultaneously transmit two different data streams (formatted according to two different protocols) over a single optical wavelength. A first data stream that is encapsulated for transport using a first transport protocol, and a second data stream that is encapsulated for transport using a second transport protocol are received. The first data stream is modulated on a wavelength with a first polarization mode of a polarization division modulation scheme to produce a first modulated data stream and the second data stream is modulated on the wavelength with a second polarization mode of the polarization division multiplex transmission scheme to produce a second modulated data stream having the second polarization mode. The second polarization mode is orthogonal to the first polarization mode. The first and second data streams are combined onto a single wavelength for transmission over a single optical fiber using a polarization beam combiner.

Abstract: Carrier phase estimation techniques are provided for processing a received optical signal having a carrier modulated according to a modulation scheme. First and second carrier phase estimation operations are performed on a digital signal derived from an optical carrier obtained from the received optical signal using coherent optical reception. The first carrier phase estimation operation tracks relatively fast phase variations of the optical carrier of the received optical signal to produce a first carrier phase estimation and the second carrier phase estimation operation tracks relatively slow phase variations of the optical carrier of the received optical signal to produce a second carrier phase estimation. A difference between the first and second carrier phase estimations is computed. Occurrence of a cycle slip is determined when the difference is greater than a threshold. A correction is applied to the first carrier phase estimation when the low pass filtered difference exceeds the threshold.

Abstract: This invention relates to a receiver circuit which comprises an equalizer (27) and an error decorrelator (25). The error decorrelator being configured for changing (501; 601, 602) the position of symbols. The invention further relates to a corresponding method. This invention finally relates to an interleaving or deinterleaving method which comprises selecting a first number of symbols (204; 302) within a stream of digital data (13; 28) thereby obtaining selected symbols. The method further comprises exchanging (601, 602) the position of at least half of said first number of symbols of said selected symbols with the position of other symbols from said selected symbols. The invention further relates to an interleaving or deinterleaving circuit.

Abstract: A system configured to maintain a consistent local-oscillator-power-to-primary-signal-power ratio (LO/SIG ratio).