General Instrument Corporation

Freescale Semiconductor,inc.

Timothy J Brophy

Robert L Howald

Shutong Zhou

Richard A Meier

Barbara Foley Barenburg

Erik C Metz

Amarildo J C Vieira

Daniel Charles Fiorella, Iii

Brian T Harte

High quality epitaxial layers of monocrystalline materials can be grown overlying monocrystalline substrates such as large silicon wafers by forming a compliant substrate for growing the monocrystalline layers. An accommodating buffer layer comprises a layer of monocrystalline oxide spaced apart from a silicon wafer by an amorphous interface layer of silicon oxide. The amorphous interface layer dissipates strain and permits the growth of a high quality monocrystalline oxide accommodating buffer layer. The accommodating buffer layer is lattice matched to both the underlying silicon wafer and the overlying monocrystalline material layer. Any lattice mismatch between the accommodating buffer layer and the underlying silicon substrate is taken care of by the amorphous interface layer. In addition, formation of a compliant substrate may include utilizing surfactant enhanced epitaxy, epitaxial growth of single crystal silicon onto single crystal oxide, and epitaxial growth of Zintl phase materials. A wavelength locker for stabilizing a wavelength of an optical output signal from an optical transmitter is formed overlying the silicon wafer.

Fabrication of a wavelength locker within a semiconductor structure

An optical transmitter is provided that includes a laser subassembly generating an optical signal having a plurality of operating characteristics. A controller, which drives the laser subassembly by applying at least one control parameter thereto, includes a predetermined, empirically derived database relating the plurality of operating characteristics of the laser subassembly to the control parameters. The controller adjusts at least one control parameter based at least in part on data extracted from the database so that the operating characteristic is substantially optimized.

Return path transmitter having a closed laser control loop that is employed in a hybrid fiber / coax transmission

An in-line distortion generator for coupling in-line with a non-linear device (NLD) produces an output signal of useful amplitude, but with low composite triple beat and cross modulation distortions. The distortion generator comprises an instant controlled non-linear attenuator which utilizes the non-linear current flowing through a pair of diodes to provide the proper amount of signal attenuation over the entire frequency bandwidth. The distortion generator circuitry is always matched to the NLD, thereby ensuring a frequency response that is predictable and predefined. The distortion generator may also include a temperature compensation circuit to ensure consistent operation throughout a wide temperature range.

Non-linear distortion generator

An HFC return path system uses digital conversion and transport at the fiber optic node, so as to replace analog laser technology with a high-speed baseband digital technology, thereby providing immunity from the troublesome analog laser impairments, enabling longer distances to be covered, potentially avoiding the need for hub repeater hardware required in analog systems, among other benefits.

Growing community of inventors

Holland, PA, United States of America

Timothy J Brophy