An adjusting method for stabilizing optical characteristic parameters applicable to transmitter optical subassemblies with silicon photonic chips is provided. The adjusting method might include: sensing an initial optical signal emitted by the transmitter optical subassembly with first control component, controlling phase setting parameter of the silicon photonic chip with the first control component to change the transmitter optical subassembly from emitting the initial optical signal to emitting a first modified optical signal, transmitting a power target value to second control component when the first modified optical signal conforms to the phase target value and sensing the first modified optical signal with the second control component, and controlling a bias current of the transmitter optical subassembly according to the first modified optical signal and the power target value to change the transmitter optical subassembly from emitting the first modified optical signal to emitting a second modified optical signal.

An adjusting method for stabilizing optical characteristic parameters applicable to transmitter optical subassemblies with silicon photonic chips is provided. The adjusting method might include: sensing an initial optical signal emitted by the transmitter optical subassembly with first control component, controlling phase setting parameter of the silicon photonic chip with the first control component to change the transmitter optical subassembly from emitting the initial optical signal to emitting a first modified optical signal, transmitting a power target value to second control component when the first modified optical signal conforms to the phase target value and sensing the first modified optical signal with the second control component, and controlling a bias current of the transmitter optical subassembly according to the first modified optical signal and the power target value to change the transmitter optical subassembly from emitting the first modified optical signal to emitting a second modified optical signal.

An optical transmitter transmits a modulated optical signal in which each symbol carries M bits. M is an integer larger than one. The optical transmitter includes: a signal generation circuit configured to generate M×N binary electric signals based on transmission data, bit rates of the M×N binary electric signals being equal to each other, N being an integer larger than one, when the optical transmitter multiplexes N optical signals in time-division multiplexing; a Mach-Zehnder interferometer; and M×N phase-shift elements provided along an optical path of the Mach-Zehnder interferometer and respectively configured to shift phases of light propagated in the optical path corresponding to the M×N binary electric signals. The M×N phase-shift segments are comprised of N electrode groups. Each of the N electrode groups includes M or more electrodes to which corresponding M binary electric signals among the M×N binary electric signals are given.

An optical transmitter transmits a modulated optical signal in which each symbol carries M bits. M is an integer larger than one. The optical transmitter includes: a signal generation circuit configured to generate M×N binary electric signals based on transmission data, bit rates of the M×N binary electric signals being equal to each other, N being an integer larger than one, when the optical transmitter multiplexes N optical signals in time-division multiplexing; a Mach-Zehnder interferometer; and M×N phase-shift elements provided along an optical path of the Mach-Zehnder interferometer and respectively configured to shift phases of light propagated in the optical path corresponding to the M×N binary electric signals. The M×N phase-shift segments are comprised of N electrode groups. Each of the N electrode groups includes M or more electrodes to which corresponding M binary electric signals among the M×N binary electric signals are given.

Proposed are an optimal operation method of a high-frequency dithering technique for compensating for interference noise in an analog optical transmission-based mobile fronthaul network, and a transmitter using same. An interference noise compensation method using high-frequency phase dithering performed in an analog optical transmission-based mobile fronthaul network may include the steps in which: a frequency-multiplexed wireless signal is converted in an optical transmitter to an intensity-modulated optical signal; and the phase of the optical signal intensity-modulated in the optical transmitter is dithered with an Orthogonal Frequency-Division Multiplexing (OFDM) signal.

A high-speed optical transceiver integrated chip drive circuit with phase delay compensation function includes a transmitting end drive circuit to drive the laser to emit light to transmit signals and a receiving end drive circuit to optimize the signal degradation caused by the signal sent by the transmitting end drive circuit to the laser via the transmission backplane; a long code phase lead adjustment circuit is arranged on the main channel of the transmitting end drive circuit, and a long code phase lag adjustment circuit is set on the main channel of the receiving end drive circuit. The present invention is used to optimize high-speed signals and solve the problem that the CML drive circuit at the receiving end or the laser drive circuit at the transmitting end cannot compensate the difference between the group delay and phase delay for the high-speed signal after passing through the backplane (Laser device).

A high-speed optical transceiver integrated chip drive circuit with phase delay compensation function includes a transmitting end drive circuit to drive the laser to emit light to transmit signals and a receiving end drive circuit to optimize the signal degradation caused by the signal sent by the transmitting end drive circuit to the laser via the transmission backplane; a long code phase lead adjustment circuit is arranged on the main channel of the transmitting end drive circuit, and a long code phase lag adjustment circuit is set on the main channel of the receiving end drive circuit. The present invention is used to optimize high-speed signals and solve the problem that the CML drive circuit at the receiving end or the laser drive circuit at the transmitting end cannot compensate the difference between the group delay and phase delay for the high-speed signal after passing through the backplane (Laser device).

Disclosed is a time division quadrature homodyne CV QKD system, and a continuous variable quantum key distribution system which includes: a transmitter generating an optical pulse of quantum state data by using continuous light according to data of a transmission target encryption key; and a receiver separating the optical pulse received from a channel into two paths and fixing phases of two signals having a time difference of one period of the optical pulse to orthogonal phases, and then generating bit information through state detection by a time division homodyne detection from interacted signals.

Disclosed is a time division quadrature homodyne CV QKD system, and a continuous variable quantum key distribution system which includes: a transmitter generating an optical pulse of quantum state data by using continuous light according to data of a transmission target encryption key; and a receiver separating the optical pulse received from a channel into two paths and fixing phases of two signals having a time difference of one period of the optical pulse to orthogonal phases, and then generating bit information through state detection by a time division homodyne detection from interacted signals.

A method for chromatic dispersion pre-compensation in an optical communication network includes (1) distorting an original modulated signal according to an inverse of a transmission function of the optical communication network, to generate a compensated signal, (2) modulating a magnitude of an optical signal in response to a magnitude of the compensated signal, and (3) modulating a phase of the optical signal, after modulating the magnitude of the optical signal, in response to a phase of the compensated signal.