Abstract:
A circuit that allows the control of a parameter in each arm of a Mach-Zehnder interferometer or modulator in push-pull mode using a single control terminal and a ground (or a differential driving circuit). The parameter that is controlled can be a phase shift, a modulation or an attenuation. The magnitude and the frequency of the parameter can be adjusted.
Abstract:
One example of a system includes an optical modulator, a push-pull driver, and a compensation circuit. The optical modulator has a nonlinear capacitance. The push-pull driver is electrically coupled across the optical modulator. The push-pull driver charges the capacitance in response to a logic '1' of a level-shifted differential signal and discharges the capacitance in response to a logic '0' of the level-shifted differential signal. The compensation circuit increases the speed of the discharge of the capacitance in response to the level-shifted differential signal transitioning from a logic '1 ' to a logic '0'.
Abstract:
A Mach-Zehnder optica! modulator with a series push-pull traveling wave electrode uses a balanced coplanar stripline with lateral ground planes (G1,G2). Two signal electrodes (13A,13B) extend along the center of the optical modulator adjacent and parallel to the optical waveguides (15A,15B) in a series push-pull configuration. The ground planes (G1, G2) run parallel to the signal electrodes (13A,13B), but are spaced laterally outward from the signal electrodes (13A,13B).
Abstract:
The invention relates to a Mach-Zehnder modulator arrangement, comprising - at least one electro-optic Mach-Zehnder modulator (1) comprising a first optical waveguide (11) forming a first modulator arm and a second optical waveguide (12) forming a second modulator arm; - a travelling wave electrode arrangement (2) comprising a plurality of first waveguide electrodes (21) for applying a voltage across the first optical waveguide (11) and a plurality of second waveguide electrodes (22) for applying a voltage across the second optical waveguide (12), wherein the first waveguide electrodes (21) are capacitively coupled to the second waveguide electrodes (22); and - a driver unit (41) for supplying an alternating voltage to the travelling wave electrode arrangement (2), wherein - the driver unit (41) comprises a first output port (441) coupled to the first waveguide electrodes (21) and a second output port (442) coupled to the second waveguide electrodes (22), wherein the driver unit (41) is configured to supply a first varying signal (S+) to the first waveguide electrodes (21) via the first output port (441) and to supply a second varying signal (S-) to the second waveguide electrodes (22) via the second output port (442). The invention further relates to a method for operating a Mach-Zehnder modulator arrangement.
Abstract:
A silicon-based optical modulator structure includes one or more separate localized heating elements for changing the refractive index of an associated portion of the structure and thereby providing corrective adjustments to address unwanted variations in device performance. Heating is provided by thermo-optic devices such as, for example, silicon- based resistors, suicide resistors, forward-biased PN junctions, and the like, where any of these structures may easily be incorporated with a silicon-based optical modulator. The application of a DC voltage to any of these structures will generate heat, which then transfers into the waveguiding area. The increase in local temperature of the waveguiding area will, in turn, increase the refractive index of the waveguiding in the area. Control of the applied DC voltage results in controlling the refractive index
Abstract:
A method and apparatus is provided for controlling the bias point of a Mach-Zehnder modulator. The method begins by applying a dither signal to a DC bias that is applied to a Mach-Zehnder modulator. A component of an optical output signal provided by the Mach-Zehnder modulator that is synchronous with the dither signal is detected. The dither signal is adjusted to maintain the detected component of the optical output signal at a substantially constant value.
Abstract:
A process is given to project polymer electro-optical modulators during push-pull poling employing high voltages to the electrodes, where a thin layer of dielectric material is applied to the electrodes prior to poling, the direct current high voltage is applied, and the dielectric is removed after completion of poling.
Abstract:
A push-pull device (10) comprises: a first waveguide (W1) arranged between its first and second electrode (S11, S12) and a second waveguide (W2) arranged between its first and a second electrode (S21, S22). Electrically conductive structures (T11, T12, T21, T22) extend away from one or more of the electrodes (S11, S12, S21, S22) for electrically connecting at least two of the electrodes (S11, S12, S21, S22). The waveguides (W1, W2) and the electrodes (S11, S12, S21, S22) originate from a pre-fabrication process. The waveguides (W1, W2) are poled by a poling (P) originating from a poling process. The electrically conductive structures (T11, T12, T21, T22) originating: from the pre-fabrication process, wherein one or more of the electrically conductive structures (T11, T12, T21, T22) extend to one or more electrically non-conductive gaps (G1, G2), and wherein the device (10) further comprises one or more electrically conductive elements (C1, C2) for electrically connecting two of the electrodes (S11, S12, S21, S22), the electrically conductive elements (C1, C2) being related to the electrically non-conductive gaps (G1, G2) and originating from a post-fabrication process; and/or from a post-fabrication process.