Topic
Optical modulator
About: Optical modulator is a research topic. Over the lifetime, 14068 publications have been published within this topic receiving 196932 citations.
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Patent•
18 May 2005TL;DR: In this paper, a reverse biased lateral PN diode (PN) is constructed in a silicon rib optical waveguide and the depletion region at the PN junction overlaps with the center of a guided optical mode propagating through the waveguide.
Abstract: High speed optical modulators (100) can be made of a reverse biased lateral PN diode (105) formed in a silicon rib optical waveguide (112) disposed on a SOI or other silicon based substrate (100). A PN junction is formed at the boundary of the P and N doped regions (120, 130) The depletion region at the PN junction (106) overlaps with the center of a guided optical mode propagating through the waveguide (110). Electrically modulating a reverse biased lateral PN diode (105) causes a phase shift in an optical wave propagating through the waveguide (110). Prior art forward biased PN and PIN diode modulators have been relatively low speed devices.
68 citations
Patent•
24 Mar 1978TL;DR: In this article, the authors have shown that the different electric field orientations electrooptically induce different changes in the index of refraction for waves of different polarization in the guides, this permits improved electrooptic control over both TM-like and TE-like modes.
Abstract: Optical channel waveguide switches/modulators having polarization-independent operation are disclosed. Electrodes are disposed in proximity to the waveguide channels to provide an electric field that is primarily horizontally directed in at least one channel and an electric field that is primarily vertically directed in at least one channel. Since the different electric-field orientations electrooptically induce different changes in the index of refraction for waves of different polarization in the guides, this permits improved electrooptic control over both TM-like and TE-like modes. Embodiments of both modal interference switches/modulators and branching waveguide switches/modulators are disclosed.
68 citations
Patent•
05 Apr 1984TL;DR: In this article, a data gathering system comprising a single optical fiber having one or more modulators formed thereon, means for launching into the fiber an interrogating light pulse which propagates in a first direction, and means for generating at each modulator an optical return signal which has an intensity which is variable in response to variations in an external signal incident at the modulator.
Abstract: A data gathering system comprising a single optical fiber having one or more modulators formed thereon, means for launching into the fiber an interrogating light pulse which propagates in a first direction, means for generating at each modulator an optical return signal which propagates in the fiber in a second direction opposite the first direction and which has an intensity which is variable in response to variations in an external signal incident at the modulator, and means for detecting and processing each such return signal. The return signal comprises a portion of the interrogating light pulse which is coupled into the fiber in the second direction via evanescent coupling. The return signal from each modulator (or array of modulators) is identified via time division multiplexing. A signal processing means may be coupled to the fiber for generating a unique return signal from each of one or more modulator arrays, each array comprising a selected subset of the modulators. In a preferred embodiment, each modulator comprises a looped section of the fiber having a coupling region in which the distance between adjacent fiber segments is variable in response to variations in an external signal incident thereon. In another embodiment, each modulator comprises a short fiber segment positioned adjacent to the main fiber and separated therefrom by a distance variable in response to pressure changes incident on the modulator.
68 citations
TL;DR: In this paper, the effects of dispersion in material properties, occurring near the acoustic resonance, on bandwidth and drive voltage were investigated in a Mach-Zehnder interferometer with and without etched ridges.
Abstract: Frequency dependent drive voltage is reported in velocity matched, packaged, Mach-Zehnder interferometers, made on Z-cut, Y-propagating LiNbO/sub 3/, with and without etched ridges. Drive voltages of /spl sim/7 V at 40 GHz are demonstrated, with the etched ridge device showing a 1/2-1 V advantage. Microwave modeling allowed the extraction of the effects of dispersion in material properties, occurring near the acoustic resonance, on bandwidth and drive voltage.
68 citations
TL;DR: Various optical information processing architectures are described for applications such as database retrieval, neural network implementation, and image correlation, and selected systems are experimentally demonstrated.
Abstract: We describe the use of optical memory disks as elements in optical information processing architectures. The optical disk is an optical memory devicew ith a storage capacity approaching 1010b its which is naturally suited to parallel access. We discuss optical disk characteristics which are important in optical computing systems such as contrast, diffraction efficiency, and phase uniformity. We describe techniques for holographic storage on optical disks and present reconstructions of several types of computer-generated holograms. Various optical information processing architectures are described for applications such as database retrieval, neural network implementation, and image correlation. Selected systems are experimentally demonstrated.
68 citations