A phase modulation device including a diode-type phase modulator having a pair of side terminals connected to two sides of an optical waveguide core along an optical axis of the optical waveguide core, and a control unit that controls electrical signals to be input to the phase modulator, the side terminal of the phase modulator being divided into a plurality of portions along the optical axis of the optical waveguide core, the phase modulator having electrodes 15 respectively provided on the divided side terminals and electrically separated from each other, the control unit having switches and constant-current sources connected to the electrodes of the side terminals and controls stepwise the amount of change in phase of propagating light in the optical waveguide core according to the number of the switches turned on.

A transmission device includes a first optical modulator configured to modulate, based on a packet signal for each of packets, input light into an optical packet signal and to output an optical packet signal for each of the packets; a generation circuit configured to generate an adjustment signal that adjusts slopes of a rise and a fall of a waveform of the optical packet signal; and a second optical modulator configured to modulate the optical packet signal from the first optical modulator and adjust, based on the adjustment signal, the slopes of the rise and the fall of the waveform of the optical packet signal.

The disclosed technology allows for 1+1 optical protection and may improve coherent module output optical power by 3 dB over similar transmitter (Tx) and receiver (Rx) implementation complexity, as well as allow for integration into existing datacenter formats.

Device for modulating the intensity of an optical signal on four levels, this device comprising: a first resonant ring modulator comprising an output port capable of delivering a first modulated optical signal, a second resonant ring modulator comprising an output port capable of delivering a second modulated optical signal, an optical assembler comprising: a first input optically coupled to the output port of the second resonant ring modulator, a second input optically coupled to the output port of the first resonant ring modulator, and an output capable of delivering the optical signal of which the intensity is modulated on four different levels constructed by combining the optical signals received on its first and second inputs.

An optical modulator for generating quadrature amplitude modulation (nQAM) and phase-shift keying (nPSK) signals with tunable modulation efficiency. The modulator includes a controlling circuit for adjusting the modulation efficiency or modulation depth of the modulator by controlling the direct current (DC) bias.

In one aspect, the present disclosure relates to a communications system which, in one embodiment, includes a phase-correlated, orthogonally-polarized, light-stream generator (POLG) for preparing light into phase coherent light streams having defined states of polarization and spectral composition. In one embodiment, the POLG includes a light source configured to emit light having a predetermined wavelength and a polarization apparatus configured to prepare light from the light source into particular states of polarization. The POLG also includes a phase modulator configured to produce light having a plurality of wavelengths and configured to retard the phase of propagation of light with a first state of linear polarization while not retarding the phase of light with a state of linear polarization orthogonal to the first state of linear polarization when an external electric field is applied. The POLG also includes an electrical oscillator configured to periodically apply an electric field to the phase modulator.

The present disclosure relates to the field of optical communication, particularly to an optical module. An optical module according to embodiments of the disclosure includes: a laser device including an emission region, and a modulation region to which light emitted by the emission region is transmitted; a bias circuit connected with the emission region, configured to drive the emission region to emit light at stable optical power; a modulation circuit connected with the modulation region, configured to drive the modulation region, so that the modulation region varies the optical power of the light emitted from the emission region; and a semiconductor optical amplifier configured to receive the light from the modulation region, and to vary the optical power of the light.

An optical module switch device includes a first serial-parallel-converter coupled to first signal-lines coupled to optical modules, and second signal-lines, a number of the second signal-lines being greater than the first signal-lines thereof, and configured to transmit/receive first signals at a first transmission-rate to/from the optical modules by using the first signal-lines, respectively, a second serial-parallel-converter coupled to second signal-lines coupled to the first serial-parallel-converter, and third signal-lines, a number of the third lines being greater than the second signal-lines thereof, and configured to transmit/receive second signals at a second transmission-rate lower than the first transmission-rate to/from the first serial-parallel-converter by using the second signal-lines, respectively, and a switch circuit coupled to the third signal-lines, and configured to transmit/receive third signals at a third transmission-rate lower than the second transmission-rate to/from the second serial-parallel-converter by using the third signal-lines, respectively, to perform routing processing based on the received third signals.

An apparatus, comprising: Mach-Zehnder modulators (MZMs) numbered MZM #1 to MZM #n that exhibit nonlinearity between an input electrical domain signal and an output optical domain signal; a waveform source for applying a first voltage waveform to a first optical arm of said MZM #1; a laser source configured to direct laser light into the two arms of at least said MZM #1 to produce a first output optical domain signal; the apparatus being provided for utilizing said first output optical signal and the nonlinearities of MZMs numbered MZM #2 to said MZM #n to produce a final output voltage waveform that, compared to said input voltage, comprises at least one of: a shorter rise time, a shorter fall time, an increased signal temporal resolution or small signal dynamic range, an increased vertical resolution for small signals or large signals, a reduced noise on small signals or large signals and an increased bandwidth.

A digital-to-analog optical modulator including a first waveguide arm configured to receive a light at a first end and to output a modulated light at a second end, and a first plurality of phase shifter segments, two segments from the first plurality of phase shifter segments having the same length and optically coupled to the first waveguide arm configured to generate the modulated light in response to a digital electrical drive signal. A digital-to-analog optical modulator including a first waveguide arm comprising a first end and a second end, a first plurality of phase shifter segments optically coupled to the first waveguide arm, at least two of the first plurality of phase shifter segments are the same length, and a second waveguide arm optically coupled to the first waveguide arm at the first end and the second end.