Methods and devices that provide a variable-bandwidth optical filter with frequency tuning are disclosed. A universal variable bandwidth optical filter architecture is disclosed, based on microring resonators that can vary both operation wavelength and bandwidth with no extra complexity relative to conventional wavelength tunable filters. The filter architecture provides a universal filter design for any arbitrary shape of filter response, such as second-order, fourth-order, sixth-order, and so on. The filter characteristics—insertion loss, in-band ripple, and out-of-band rejection level—may be maintained over the bandwidth tuning range. There is no need for extra heaters to tune the filter's operating bandwidth, as the same heaters used to tune the filter frequency can be used to tune filter bandwidth. The device can be used as an add/drop filter.

An optical network component and method are herein described. The system and method include determining a first power of an optical modulator using a first photodetector and a second power of the transmitter using a second photodetector, determining a contrast ratio based on the first power and the second power, and determining a modulation loss based on the contrast ratio.

A transmission device including a multi-division optical modulator having a plurality of modulation segments, the transmission device includes a driver circuit configured to output binary data for each bit based on an input electrical signal, and an optical modulator configured to have a multilevel modulation segment driven by a first drive signal including two or more bit signal from the driver circuit, and plural binary modulation segments driven by second drive signal including only one bit signal from the driver circuit, wherein the multilevel modulation segment incudes a first phase shifter disposed on each arm of the optical modulator, the binary modulation segment includes a plurality of second phase shifters arranged along each arm of the optical modulator, and lengths of the second phase shifters are all the same and are shorter than a length of the first phase shifter.

An optical transceiver including a submount, a Mach-Zehnder Modulator (MZM), bonding wires, and a low pass filter type matching network is provided. The MZM includes an input port and an output port and disposed on the submount. The bonding wires are coupled to the submount and the MZM. The low pass filter type matching network is coupled to the bonding wires and is configured to absorb inductance of the bonding wires at a high frequency.

Embodiments of the disclosure pertain to an optical modulator including an m*n optical coupler, first and second waveguides coupled or connected to the m*n optical coupler, a first phase shifter coupled to the first waveguide, and first and second loop mirrors at respective ends of the first and second waveguides opposite from the m*n optical coupler. The m*n optical coupler is configured to combine substantially similar or identical continuous light beams (at least one of which may be phase-shifted) returned through the first and second waveguides by the first and second loop mirrors to form a modulated optical signal. A compound optical modulator, a modulated or modulatable laser, and methods of using and manufacturing the optical modulators, are also disclosed.

Embodiments of the disclosure pertain to an optical modulator including an m*n optical coupler, first and second waveguides coupled or connected to the m*n optical coupler, a first phase shifter coupled to the first waveguide, and first and second loop mirrors at respective ends of the first and second waveguides opposite from the m*n optical coupler. The m*n optical coupler is configured to combine substantially similar or identical continuous light beams (at least one of which may be phase-shifted) returned through the first and second waveguides by the first and second loop mirrors to form a modulated optical signal. A compound optical modulator, a modulated or modulatable laser, and methods of using and manufacturing the optical modulators, are also disclosed.

An optical transmitter, an optical receiver, and an optical transmission method are disclosed. The optical transmitter includes an optical signal generator, N spreaders, N pairs of data modulators, and a combiner, where the optical signal generator generates N optical carriers; an i.sup.th spreader spreads an i.sup.th optical carrier, to obtain a spread optical signal having two subcarriers; splits the spread optical signal into a first optical signal and a second optical signal; and delays the second optical signal to obtain a third optical signal; an i.sup.th pair of data modulators modulate the first optical signal and the third optical signal to obtain a pair of modulated optical signals, transmit the pair of modulated optical signals to the combiner, where the pair of modulated optical signals reaching the combiner differ by 1/(4 fsi) in time domain; and the combiner combines, into one optical signal, N pairs of modulated optical signals.

A system including at least one input optical waveguide configured to receive an optical wave, at least one digital input port configured to receive a series of digital input values, each digital input value including two or more bits, and an optical modulator coupled to the input optical waveguide. The optical modulator includes an optical waveguide portion that includes multiple optical waveguide segments associated with diode sections positioned along the optical waveguide segments, in which the diode sections are configured to apply different respective modulation contributions to an optical wave propagating through the optical waveguide portion.

An optical modulator according to embodiments includes a first MZI and a second MZI each including a first optical coupler that splits CW light into two, a second optical coupler that couples the CW light split by the first optical coupler and outputs the CW light, and a bias electrode that adjusts a phase of the CW light split by the first optical coupler, a third optical coupler that couples outputs of the first MZI and the second MZI with at a predetermined ratio and outputs the light, and a bias adjustment circuit that adjusts an output voltage of a bias power supply applied to a bias electrode so that an optical path length difference between the CW light beams split by the first optical coupler is a predetermined times a carrier wavelength under a condition that an output of a differential output amplifier is a zero level, in accordance with an operating mode of the own apparatus.

An optical transceiver including a submount, a Mach-Zehnder Modulator (MZM), bonding wires, and a low pass filter type matching network is provided. The MZM includes an input port and an output port and disposed on the submount. The bonding wires are coupled to the submount and the MZM. The low pass filter type matching network is coupled to the bonding wires and is configured to absorb inductance of the bonding wires at a high frequency.