Abstract:
A method for fabricating an optical modulator includes forming n-type layer, a first oxide portion on a portion of the n-type layer, and a second oxide portion on a second portion of the n-type layer, patterning a first masking layer over the first oxide portion, portions of a planar surface of the n-type layer, and portions of the second oxide portion, implanting p-type dopants in the n-type layer to form a first p-type region and a second p-type region, removing the first masking layer, patterning a second masking layer over the first oxide portion, a portion of the first p-type region, and a portion of the n-type layer, and implanting p-type dopants in exposed portions of the n-type layer, exposed portions of the first p-type region, and regions of the n-type layer and the second p-type region disposed between the substrate and the second oxide portion.
Abstract:
A phase shifter includes an optical waveguide, a plurality of impurity regions and a plurality of electrodes. The optical waveguide receives an optical input signal and outputs an optical output signal. The impurity regions include respective charge carriers. The impurity regions are disposed in contact with the optical waveguide at respective contact surface, where at least one of the contact surfaces has a zigzag pattern. The electrodes are connected to the respective impurity regions. Application of an electrical signal to at least one of the electrodes phase-shifts the optical output signal with respect to the optical input signal. Therefore, the phase shifter may efficiently vary a magnitude of the phase shift of the optical output signal.
Abstract:
Method and apparatus are provided for displaying an image to a viewer with reduced visual artifacts. The apparatus comprises a display panel for forming the image using an array of pixels with distributed active regions, and a viewing arrangement optically situated between the display panel and the viewer for transferring the image formed on the display panel to the viewer with limited angular pixel subtense. The distributed active regions of the pixels are desirably divided into at least two simultaneously switched portions at least partly separated by or surrounding a significant portion of the non-switchable region. First order spatial harmonics and associated artifacts are reduced by the distributed apertures and second order and higher harmonics are reduced by limiting the pixel subtense angle seen by the viewer. A significant reduction in visual artifacts arising from the periodic structure of the display panel is obtained.
Abstract:
The present invention relates to a device for velocity matching between optical and electrical signals in a waveguide structure comprising first waveguiding means for optical signals and second waveguiding means for electrical signals. The cross-section of the waveguide structure varies dielectrically in the direction of the propagation.