Abstract:
A PIN electro-optical traveling wave modulator (10) including diffraction gratings (34, 36) positioned at opposing sides of an optical waveguide (20) that act to change the propagation pattern of the waveguide (20). The modulator (10) includes an N-type layer (14), a P-type layer (18) and an intrinsic layer (16) acting as the waveguide (20). A metal electrode (26) is in electrical contact with the N-type layer (14), and a metal electrode (30) is in electrical contact with the P-type layer (18). The electrodes (26, 30) define an RF transmission line. An optical wave (22) propagates along the waveguide (20) and interacts with the gratings (34, 36) which slow the optical wave (22) to match its speed to the speed of the RF wave in the transmission line. In one embodiment, the gratings (34, 36) are 2-D gratings formed by vertical holes (38) in the waveguide (20).
Abstract:
A magneto-optic modulator 1 modulates signals from a superconducting circuit such as a single-flux-quantum SFQ logic system onto a carrier wave light beam. The modulator is formed by depositing a magneto-optic material 3 such as EuSe onto a superconducting ground plane 5 such as that of the circuit. A microwave microstrip line 7 is formed on the magneto-optic material and carries a signal from the circuit. The signal induces an H field in the magneto-optic material which causes the magneto-optic material to modulate the light.
Abstract:
An electro-optic modulator is provided. The electro-optic modulator includes: an optical splitter; a first optical waveguide and a second optical waveguide; traveling wave electrodes including a first grounding electrode, a first signal electrode, a second signal electrode, and a second grounding electrode; extension electrodes including at least one first signal sub-electrode and two second signal sub-electrodes, where the two second signal sub-electrodes are arranged on both sides of the at least one first signal sub-electrode and the first signal electrode is electrically connected to the first signal sub-electrodes, and the second signal electrode is electrically connected to the second signal sub-electrodes.
Abstract:
A velocity mismatch between optical signals and microwave electrical signals in electro-optic devices, such as modulators, may be compensated by utilizing different lengths of bends in the optical waveguides as compared to the microwave electrodes to match the velocity of the microwave signal propagating along the coplanar waveguide to the velocity of the optical signal. To ensure the electrode bends do not affect the light in the optical waveguide bends, the electrode may have to be rerouted, e.g. above or below, the optical waveguide layer. To ensure that the pair of optical waveguides have the same optical length, a waveguide crossing may be used to cross the first waveguide through the second waveguide.
Abstract:
Provided is a distributed optical phase modulator, comprising: a substrate (10); an optical waveguide (20) arranged on the substrate (10); a drive electrode (30) that is arranged on the substrate (10) and comprises a plurality of sub drive electrodes (31) arranged at intervals; and at least one shielding electrode (40), wherein at least some shielding electrodes and the sub drive electrodes (31) are arranged at intervals. The optical waveguide (20) sequentially passes through the sub drive electrodes (31) and the shielding electrodes (40). The length of each part of the drive electrode (30) is far less than the total length of an equivalent traditional modulator, and the drive signal voltage of each part is also far less than the drive signal voltage of the equivalent traditional modulator. In each part of the drive electrode (30), the propagation of an optical signal and the propagation of an electrical signal can be approximately synchronous, even synchronous. The phenomenon of walk-off between the optical signal and the electrical signal is minimized, and the upper limit of a modulation bandwidth is improved. The shielding electrodes (40) are respectively arranged between the sub drive electrodes (31), so that crosstalk between the sub drive electrodes (31) can be shielded, and crosstalk between the sub drive electrodes (31) can be greatly reduced.
Abstract:
A travelling wave electro-optic modulator comprising
a substrate; first and second parallel spaced apart electrode strips arranged on the substrate; first and second optical waveguides arranged on the substrate, the optical waveguides being positioned between the first and second electrode strips and extending parallel thereto; the first electrode strip comprising at least one portion extending proximate to the first optical waveguide; the second electrode strip comprising at least one portion extending proximate to the second optical waveguide; a semiconductive backplane layer arranged within the substrate and extending between the waveguides; and, a matched termination connected to the first and second electrode strips, the matched termination comprising
(a) a serpentine electrically conductive strip arranged on the substrate and connecting the first and second electrode strips together; and, (b) a semiconductive backplane matching element, the backplane matching element comprising a plurality of semiconductive backplane plates connected together by at least one semiconductive backplane arm, the plates and at least one backplane arm being arranged within the substrate, the plates being arranged proximate to the electrode strips such that each electrode strip is capacitively coupled to at least one backplane plate;
the serpentine electrically conductive strip being arranged such that at least a portion of its length is proximate to at least one backplane arm such that the two are electrically coupled together.
Abstract:
A distributed traveling-wave Mach-Zehnder modulator driver having a plurality of modulation stages that operate cooperatively (in-phase) to provide a signal suitable for use in a 100 Gb/s optical fiber transmitter at power levels that are compatible with conventional semiconductor devices and conventional semiconductor processing is described.
Abstract:
Provided is a substrate-type optical waveguide, having a phase modulation function, (i) in which a reflection of a signal to be inputted via a coplanar line is restrained and (ii) which consumes less power. In a case where the substrate-type optical waveguide is partitioned into a plurality of sections by cross sections orthogonal to a direction in which light propagates through a core, a local capacitance in each of the plurality of sections gradually increases as a distance from an entrance end surface increases.