An optical modulator includes: an optical modulation element which includes signal electrodes; lead pins; and a relay substrate in which a conductor pattern which electrically connects each of the lead pins and each of the signal electrodes to each other are formed, and the optical modulator is configured such that the amount of radiation of a high frequency at a connection portion between the conductor pattern and the signal electrode is increased compared to a portion other than the connection portion.

The bias error in a fiber optic system comprising a fiber optic gyroscope can be determined by determining of at least two different values for rotation rate by an evaluation unit of the fiber optic gyroscope for almost constant rotation rate applied to the fiber optic gyroscope and/or can be reduced by a linear combination of the at least two different values for the rotation rate. A fiber optic system that is suitable for carrying out this method comprises besides the fiber optic gyroscope a control device that is configured to control at least one element of the fiber optic gyroscope such that at least two different values for the rotation rate are determined by the evaluation unit of the fiber optic gyroscope for almost constant rotation rate applied to the fiber optic gyroscope.

An optical module includes a substrate with a plurality of pairs, which are parallel to each other, spaced in a width direction of the substrate, of optical waveguides formed thereon, each pair being made up of a first optical waveguide that guides a first beam and a second optical waveguide that guides a second beam that monitors the first beam, and a lens that has an incident surface facing at least one pair of the plurality of pairs, collimates, for each of the at least one pair, the first and second beams that emerge from the pair and that differ from each other in at least any one of their incident positions and incident directions on the incident surface, and directs the first and second beams having been collimated and leaving the lens in different directions that depend on the incident positions or the incident directions.

A silicon photonics transmitter and a method therefor are disclosed. The silicon photonics optical transmitter includes a Mach-Zehnder modulator, a plurality of optical couplers, a plurality of photodetectors, a monitor configured to measure an input optical power based on a sum of photocurrents or photovoltages corresponding to the plurality of photodetectors, and a modulator controller configured to control a voltage supplied to the Mach-Zehnder modulator based on a difference between the photocurrents or the photovoltages corresponding to the plurality of photodetectors.

A pluggable electric connector can communicate a communication data signal and a control signal with an optical communication apparatus. An optical signal output unit includes a Mach-Zehnder type optical modulator including a phase modulation area and outputs an optical modulation signal modulated according to the communication data signal. An optical power control unit can control optical power of the optical modulation signal. A pluggable optical receptor can output the optical modulation signal to an optical fiber. A control unit controls a modulation operation of the optical signal output unit and the bias voltage applied to the phase modulation area. The control unit determines the bias voltage applied to the phase modulation area according to phase angle information of the control signal. The optical signal output unit applies the bias voltage determined by the control unit to the phase modulation area.

Modulation electrodes, bias electrodes, and bias electrodes are disposed in this order in a light wave-travelling direction in an optical modulation region modulating light having a wavelength. On the other hand, in an optical modulation region modulating light having a wavelength, the bias electrodes, the bias electrodes, and the modulation electrodes are disposed in this order in the light wave-travelling direction. That is, an order of the modulation electrodes and the bias electrodes in a longitudinal direction of a substrate is changed for each of the wavelengths.

An example photonic integrated circuit (PIC) includes a plurality of input ports to input light, such as a quantum state of light that comprises one or more photons, into the PIC. In addition, the PIC may include a waveguide network that includes a crossing network to combine light, and optical couplers that are coupled to the crossing network. The PIC can further include output ports to output the light.

The various embodiments described herein include a phase shifter that can have a first electrode that has a distributed shape. The phase shifter can include a second electrode. The phase shifter can include an optical waveguide between the first electrode and the second electrode. Further, the phase shifter can include an active electro-optical material that propagates light, and phase shifts the light.

An example integrated generalized Mach-Zehnder Interferometer (GMZI) to process a quantum state of light is described. A quantum state of light comprising one or more photons can be received by a first coupler network in the GMZI. Using the first coupler network, the quantum state of light is distributed to one or more of a plurality of waveguide arms in the GMZI. The phase of the quantum state of light is adjusted using a plurality of phase shifters in the GMZI. The phase is adjusted for portions of the quantum state of light in one of the plurality of waveguide arms. The phase-adjusted quantum light is received by a second coupler network in the GMZI. Using the second coupler network, the quantum state of light is combined onto one or more outputs of the waveguide arms. The combined quantum light is outputted.

An optical module includes: a substrate; a first terminal; a plurality of second terminals; a plurality of third terminals; and a plurality of wirings. The plurality of second terminals are on the substrate. The plurality of third terminals are disposed closer to an electrode than the plurality of second terminals on the substrate. The plurality of wirings extend from the plurality of second terminals through a side opposite to the first terminal and reach the electrode.