An injection locked transmitter for an optical communication network includes a master seed laser source input substantially confined to a single longitudinal mode, an input data stream, and a laser injected modulator including at least one slave laser having a resonator frequency that is injection locked to a frequency of the single longitudinal mode of the master seed laser source. The laser injected modulator is configured to receive the master seed laser source input and the input data stream, and output a laser modulated data stream.

Optical fiber interconnection systems and methods are described. One aspect includes receiving a pulse-amplitude modulated (PAM4) electrical signal at a transmitter for transmission to a receiver. The PAM4 electrical signal is decoded into a pair of non-return-to-zero (NRZ) electrical signals. The pair of NRZ electrical signals is converted into a corresponding pair of NRZ optical signals including a first NRZ optical signal and a second NRZ optical signal. The first NRZ optical signal is transmitted to a receiver over an communication channel. The second NRZ optical signal is transmitted to the receiver over the optical communication channel.

A cryogenic optoelectronic data link, comprising a sending module operating at a cryogenic temperature less than 100 K. An ultrasensitive electro-optic modulator, sensitive to input voltages of less than 10 mV, may include at least one optically active layer of graphene, which may be part of a microscale resonator, which in turn may be integrated with an optical waveguide or an optical fiber. The optoelectronic data link enables optical output of weak electrical signals from superconducting or other cryogenic electronic devices in either digital or analog form. The modulator may be integrated on the same chip as the cryogenic electrical devices. A plurality of cryogenic electrical devices may generate a plurality of electrical signals, each coupled to its own modulator. The plurality of modulators may be resonant at different frequencies, and coupled to a common optical output line to transmit a combined wavelength-division-multiplexed (WDM) optical signal.

Coherent optical communications technology for recovery of 1D and 2D formatted optical signals. For example, 1D or 2D formatted signals that travel through fiber optic media may be recovered by separating the light into X- and Y-polarization components, rotating one polarization component (e.g., Y-component) into the polarization space of the other component (e.g., Y-component into the X-polarization space), delaying the rotated component enough to avoid destructive interference and combining the delayed component with the undelayed component to form a folded optical signal, which may then be processed as a X-polarized signal.

An underwater communications system may include a first device and a second device being movable relative to one another. The first device may include a first laser transmitter configured to generate a first laser beam having a selectable spatiotemporal beam shape from among a plurality thereof, and a first controller coupled to the first laser transmitter and configured to select a spatiotemporal beam shape for the first laser beam from among the spatiotemporal beam shapes. The second device may include a second laser receiver configured to receive the first laser beam, and a second controller coupled to the second laser receiver.

The present disclosure is directed to light-distribution systems on photonic integrated circuits (PIC) that split and amplify a light signal received from at least one remotely located laser into a plurality of amplified light signals, where amplification is provided by an integrated semiconductor optical amplifier (SOA). By locating the laser remotely with respect to the SOA-based PIC, the laser and PIC can be subjected to different ambient environmental conditions. Additionally, a lower-power laser can be used since the optical loss associated with splitting is compensated for by the amplification. As a result, lower current densities and optical powers can be used in both the source laser and the SOA. In some embodiments, the sequence of power splitting and amplification is repeated multiple times, thereby enabling system to scale gracefully.

An optical communication device may include a driver component, arranged to achieve a driving voltage, and a modulator component, including a laser or arranged to receive light from a laser. The modulator component may be arranged to achieve a modulated light signal modulated based on the driving voltage. The device may include a transmission line arranged to transfer the driving voltage between the driver component and the modulator component. The transmission line may not impedance matched to the driver component, the transmission line may have an impedance which is at least 20% lower than an output impedance of the driver component, and the transmission line may be impedance matched with respect to signal reflections to the modulator component.

Optical network systems and components are disclosed, including a transmitter comprising a digital signal processor that receives data; circuitry that generate a plurality of electrical signals based on the data; a plurality of filters, each of which receiving a corresponding one of the plurality of electrical signals, a plurality of roll-off factors being associated with a respective one of the plurality of filters; a plurality of DACs that receive outputs from the digital signal processor, the outputs being indicative of outputs from the plurality of filters; a laser that supplies light; and a modulator that receives the light and outputs from the DACs, and supplies a plurality of optical subcarriers based on the outputs, such that one of the optical subcarriers has a frequency bandwidth that is wider than remaining ones of the optical subcarriers, said one of the optical subcarriers carrying information for clock recovery.

An electro-optic device, such as an optical modulator, comprises: a driver for generating a plurality of identical time-synchronized copies of an input electrical signal, and a photonic integrated circuit, including an optical waveguide structure and a plurality of phase-modulating electro-optical modulator segments. Each one of the modulator segments configured to receive a respective one of the plurality of the copies of the input electrical signal. Instead of incorporating a required phase delay between the copies of the input electrical signal into the driver structure, a multi-layer interconnect substrate is provided that includes a plurality of insulating layers alternating with a plurality of conductive layers. The plurality of conductive layers are configured to include a plurality of delay lines, each one of the plurality of delay lines electrically coupled in between the driver and the photonic integrated circuit configured to transmit a respective one of the plurality of copies of the first input electrical signal.

An injection locked transmitter for an optical communication network includes a primary seed laser source input substantially confined to a single longitudinal mode, an input data stream, and a laser injected modulator including at least one secondary laser having a resonator frequency that is injection locked to a frequency of the single longitudinal mode of the primary seed laser source. The laser injected modulator is configured to receive the primary seed laser source input and the input data stream, and output a laser modulated data stream.