Abstract: An optical external modulator includes an optical waveguide having a first interferometer section and a second interferometer section formed on an electro-optic substrate. An electrode structure disposed on the substrate transmits an RF drive signal that is applied to the first and second interferometer sections in series. A reflector optically coupled to the substrate redirects light away from the first interferometer section to the second interferometer section and provides an optical fold region that introduces an optical time delay between the first and second interferometer sections. The optical time delay is used for at least partially compensating for a velocity mismatch between the light and the RF drive signal.

Abstract: An optical external modulator includes an optical waveguide having a first interferometer section and a second interferometer section formed on an electro-optic substrate. An electrode structure disposed on the substrate transmits an RF drive signal that is applied to the first and second interferometer sections in series. A reflector optically coupled to the substrate redirects light away from the first interferometer section to the second interferometer section and provides an optical fold region that introduces an optical time delay between the first and second interferometer sections. The optical time delay is used for at least partially compensating for a velocity mismatch between the light and the RF drive signal.

Abstract: An optical digital external modulator having a cascaded arrangement of interferometers is provided. The optical modulator includes an electrode structure for applying an electric field to each interferometer in the cascade and biasing circuitry coupled to the electrode structure for biasing each interferometer at a predetermined bias point. In particular, each predetermined bias point is selected to be above quadrature and for providing improved transmission performance of digital data signals. Preferably, the modulator has a reflective design that helps to increase the modulation bandwidth, lower the drive voltage, and reduce size.

Abstract: An optical digital external modulator having a cascaded arrangement of interferometers is provided. The optical modulator includes an electrode structure for applying an electric field to each interferometer in the cascade and biasing circuitry coupled to the electrode structure for biasing each interferometer at a predetermined bias point. In particular, each predetermined bias point is selected to be above quadrature and for providing improved transmission performance of digital data signals. Preferably, the modulator has a reflective design that helps to increase the modulation bandwidth, lower the drive voltage, and reduce size.

Abstract: An electro-optic device including an optical waveguide formed in an electro-optic material that propagates an optical signal along a first direction of propagation is described. The device also includes an electrical waveguide formed in the electro-optic material and positioned co-linear relative to the optical waveguide and in electromagnetic communication with the optical waveguide, where the electrical waveguide also propagates the electrical signal in the first direction of propagation. A compensation network is electrically coupled to the electrical waveguide at a junction and propagates the electrical signal in a second direction of propagation that is substantially non-co-linear with the first direction of propagation.

Abstract: A co-planar waveguide interferometric electro-optic modulator that reduces the bias point sensitivity of the modulator to ambient temperature and to applied RF is described. The modulator includes a first and second waveguide that are formed in an electro-optic substrate. A RF electrode is positioned on the electro-optic substrate between the first and the second waveguide. A ground electrode that may include a slot is positioned proximate to the second waveguide. A guard ground electrode is positioned proximate to the first waveguide to sink heat from the RF electrode and may also balance the thermal stress in the two waveguides. A dielectric material may also be positioned proximate to the first waveguide to balance the thermal stress in the two waveguides.