Optical switch

About: Optical switch is a research topic. Over the lifetime, 28538 publications have been published within this topic receiving 351176 citations.

Advanced optical fiber communications network

Abstract: An advanced optical fiber communications network comprises a multimode optical fiber connection (one fiber or two) from a central office to an intelligent interface device in the subscriber's premises The central office includes at least a narrowband switch and a broadband switch The narrowband switch provides voice grade telephone service routing The broadband switch provides routing for video services and may comprise an ATM switch, an optical switch or the like The intelligent interface device provides a connection to the optical fiber and performs two-way wavelength division multiplexing and demultiplexing as well as any necessary signal format conversions The network has media access control functionality and utilizes a dynamic media access control procedure The optical fiber loop to the subscriber's premises has the capacity to carry at least three different wavelengths Bandwidth on the optical fiber loop is dynamically allocated to individual services on demand, and the allocation of bandwidth includes wavelength selection as well as bit rate allocation

Inter-ring cross-connect for survivable multi-wavelength optical communication networks

Abstract: A cross-connect (92) for a multi-ring, multi-channel telecommunications network, especially for a wavelength-division multiplexed (WDM) optical network. Each of the interconnected rings (94 and (100) is self-healing by provision of a redundant counter-rotating ring (96 and 98)) or excess capacity on pairs of counter-rotating rings. Because an interconnect between self-healing rings (90) does not need to connect working to protection fibers, or similarly redundant fibers, the complexity of the interconnect can be substantially reduced. For several important architectures, the interconnect can be decomposed into one or two 3x3 interconnects. Further, a wide-sense non-blocking 3x3 interconnect can be advantageously implemented as four 2x2 switches, which may be a basic building block of optical switches. A novel algorithm is available to add new paths through such a 3x3 interconnect. The interconnect can be decomposed into one or two 4x4 interconnects when another pair of add (102)/drop (104) lines are added. Such an architecture provides full connectivity between user nodes connected to the add (102)/drop (104) lines and user nodes attached to the rings.

Optical add-drop multiplexers for WDM optical communication systems

Abstract: The present invention provides an optical add-drop multiplexer for wavelength division multiplexed optical communication systems which includes first and second optical couplers which optically communicate with each other through an optical filter. The first optical coupler includes a first input port and first and second output ports while the second optical coupler includes first and second input ports and an output port An optical path optically communicates with the first output port of the first optical coupler and with the first input port of the second optical coupler and includes an optical filter for selecting portions of a wavelength division multiplexed optical signal input to the first optical coupler. The portions of the wavelength division multiplexed signal which are not sent to an input port of the second optical coupler exit the add-drop multiplexer. An optical path communicating with the second output port of the first optical coupler includes wavelength selectors configured to select one or more optical wavelengths from the wavelength division multiplexed optical signal. Optical channels to be added are sent the second input port of the second optical coupler and combined with the "through" portion of the WDM optical signal such that the output is a new wavelength division multiplexed optical signal output by the second optical coupler.

Phase-sensitive Optical Time Domain Reflectometer Assisted by First-order Raman Amplification for Distributed Vibration Sensing Over >100 km

Abstract: In this study, the authors present an experimental and theoretical description of the use of first order Raman amplification to improve the performance of a Phase-sensitive optical time domain reflectometer (φOTDR) when used for vibration measurements over very long distances. A special emphasis is given to the noise which is carefully characterized and minimized along the setup. A semiconductor optical amplifier and an optical switch are used to greatly decrease the intra-band coherent noise of the setup and balanced detection is used to minimize the effects of RIN transferred from the Raman pumps. The sensor was able to detect vibrations of up to 250 Hz (close to the limits set by the time of flight of light pulses) with a resolution of 10 m in a range of 125 km. To achieve the above performance, no post-processing was required in the φOTDR signal. The evolution of the φOTDR signal along the fiber is also shown to have a good agreement with the theoretical model.

Atomic Scale Plasmonic Switch

Abstract: The atom sets an ultimate scaling limit to Moore's law in the electronics industry. While electronics research already explores atomic scales devices, photonics research still deals with devices at the micrometer scale. Here we demonstrate that photonic scaling, similar to electronics, is only limited by the atom. More precisely, we introduce an electrically controlled plasmonic switch operating at the atomic scale. The switch allows for fast and reproducible switching by means of the relocation of an individual or, at most, a few atoms in a plasmonic cavity. Depending on the location of the atom either of two distinct plasmonic cavity resonance states are supported. Experimental results show reversible digital optical switching with an extinction ratio of 9.2 dB and operation at room temperature up to MHz with femtojoule (fJ) power consumption for a single switch operation. This demonstration of an integrated quantum device allowing to control photons at the atomic level opens intriguing perspectives for a fully integrated and highly scalable chip platform, a platform where optics, electronics, and memory may be controlled at the single-atom level.