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

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

During operation, the system receives an optical input signal, and also receives a reference optical frequency comb (OFC) signal. Next, the system uses a gapless spectral demultiplexer to spectrally slice the optical input signal to produce a set of spectral slices. The system also uses a high-contrast demultiplexer to strongly isolate each combline of the reference OFC signal to produce a set of reference comblines. Next, in a parallel manner, the system demodulates each spectral slice in the set of spectral slices centered on a single reference combline in the set of reference comblines to produce a set of baseband I/Q signals, wherein each spectral slice is demodulated based on a known code sequence. The system then digitizes the set of baseband I/Q signals to produce a set of digitized signals. Finally, the system processes the set of digitized signals to directly reconstruct a waveform for the optical input signal.

A method for transmitting data carrying optical information over an optical channel, comprising the steps of providing an optical transmitter consisting of a light source being a Mode-Locked Optical Frequency Comb (MLFC) for generating a frequency comb of multiple carriers, each of which being modulated by a baseband signal; an optical modulator for modulating each and all of the multiple carriers in a modulation bandwidth extending up to the modes' frequency spacing between the multiple carriers; performing all-optical encoding of the modulated carriers by manipulating the optical amplitude and/or phase and/or polarization of all optically modulated carriers; and transmitting, by the optical transmitter, the encoded modulated carriers to an optical receiver, over an optical channel.

An electronic device may include clocking circuitry with primary and secondary lasers that generate first and second optical local oscillator (LO) signals. A phase-locked loop (PLL) may tune the secondary laser based to phase lock the first and second optical LO signals. A self-injection locking loop path may couple an output of the secondary laser to its input. The self-injection locking loop path may include a first mixer and a second mixer. The first mixer may generate a beat signal using the first and second optical LO signals. The second mixer may generate a self-injection locking signal based on the first optical LO signal and the beat signal. A delay line or optical resonator may iteratively self-inject the self-injection locking signal onto the secondary laser. This may serve to minimize phase noise and jitter of the optical LO signals.

An electronic device may include clocking circuitry with primary and secondary lasers that generate first and second optical local oscillator (LO) signals. A phase-locked loop (PLL) may tune the secondary laser based to phase lock the first and second optical LO signals. A self-injection locking loop path may couple an output of the secondary laser to its input. The self-injection locking loop path may include a first mixer and a second mixer. The first mixer may generate a beat signal using the first and second optical LO signals. The second mixer may generate a self-injection locking signal based on the first optical LO signal and the beat signal. A delay line or optical resonator may iteratively self-inject the self-injection locking signal onto the secondary laser. This may serve to minimize phase noise and jitter of the optical LO signals.

Methods, systems, and devices for network communications to reduce optical beat interference (OBI) in upstream communications are described. For example, a fiber node may provide a seed source to injection lock upstream laser diodes. Therefore, upstream communications from each injection locked laser diode may primarily include the wavelength associated with each seed source. The seed sources may be unique to each end device and configured to minimize OBI. That is, the upstream laser diodes may be generic, but the collected seed source may enable upstream communications at varying wavelengths. The end device may provide upstream communications by externally modulating a signal generated by the injection locked laser diode.

Methods, systems, and devices for network communications to reduce optical beat interference (OBI) in upstream communications are described. For example, a fiber node may provide a seed source to injection lock upstream laser diodes. Therefore, upstream communications from each injection locked laser diode may primarily include the wavelength associated with each seed source. The seed sources may be unique to each end device and configured to minimize OBI. That is, the upstream laser diodes may be generic, but the collected seed source may enable upstream communications at varying wavelengths. The end device may provide upstream communications by externally modulating a signal generated by the injection locked laser diode.

A polarization-multiplexed self-homodyne analog coherent (PM-SH-ACD) architecture for optical communication links has a receiver section that polarization un-rotates a signal from a fiber optic cable into first and second polarized optical signals; recovers a polarization of the first and second optical signals based on a received polarization recovery signal that is based on a pilot signal measurement signal; demodulates the first optical signal into optical QPSK data and pilot tone signals; demodulates the second optical signal into an optical modulating laser light; splits the first and second optical signals into optical QPSK quadrature signals; converts the optical QPSK quadrature signals into electrical QPSK quadrature signals; detects a polarization of the pilot tone signal and outputs the pilot signal measurement signal polarization recovery signal based on the detected polarization.

A polarization-multiplexed self-homodyne analog coherent (PM-SH-ACD) architecture for optical communication links has a receiver section that polarization un-rotates a signal from a fiber optic cable into first and second polarized optical signals; recovers a polarization of the first and second optical signals based on a received polarization recovery signal that is based on a pilot signal measurement signal; demodulates the first optical signal into optical QPSK data and pilot tone signals; demodulates the second optical signal into an optical modulating laser light; splits the first and second optical signals into optical QPSK quadrature signals; converts the optical QPSK quadrature signals into electrical QPSK quadrature signals; detects a polarization of the pilot tone signal and outputs the pilot signal measurement signal polarization recovery signal based on the detected polarization.