Abstract: A Mach-Zehnder optical modulator with a series push-pull traveling wave electrode uses a balanced coplanar stripline with lateral ground planes. Two signal electrodes extend along the center of the optical modulator adjacent and parallel to the optical waveguides in a series push-pull configuration. The ground planes run parallel to the signal electrodes, but are spaced laterally outward from the signal electrodes.

Abstract: An electrical waveguide transmission device accepts a differential electrical input signal (e.g., S+ and S?) propagating along two separate signal conductors with grounded electrical return paths, and outputs the differential input signal to a series push-pull traveling wave electrode Mach-Zehnder optical modulator over a pair of output conductors that act as a return path for each other and provide a desired characteristic impedance matching that of the Mach-Zehnder optical modulator.

Abstract: A Mach-Zehnder modulator has an optical splitting element splitting an input optical signal into two optical signals that are conveyed by two optical waveguide arms, and an optical combining element combining the two optical signals into an output optical signal. Two traveling wave electrodes (TWEs) carry an electrical modulation signal to induce a change in phase of these two optical signals, and include a number of pairs of modulation electrodes positioned adjacent to the waveguide arms. At least some of the electrodes in one waveguide arm have a different shape (e.g., length or width) than the electrodes in the other waveguide arm to alter the effectiveness of the electrodes in inducing a phase change in the two optical signals.

Abstract: A tunable laser has a gain material and a mirror defining an external resonant cavity. A tunable Fabry-Perot etalon disposed along the optical path between the mirror and the gain material includes a liquid crystal layer having a variable refractive index to tune the transmission peaks of the etalon and the resonant frequency of the laser resonant cavity. A second etalon having a fixed set of transmission peaks can also be included in the laser resonant cavity. The tunable etalon is then tuned to select a resonant frequency corresponding to one of the transmission peaks of the fixed etalon.

Abstract: A monolithic optoelectronic device has a spot-size converter optically connected to a waveguide. The overclad extending over the core of the waveguide is thinner and more highly doped that the overclad of the spot-size converter. This structure can be made by applying a process of selective etching and enhanced regrowth to create selective regions of the overclad of different thickness or doping.