Abstract: An optical signaling header technique applicable to optical networks wherein packet routing information is embedded in the same channel or wavelength as the data payload so that both the header and data payload propagate through network elements with the same path and the associated delays. The technique effects survivability and security of the optical networks by encompassing conventional electronic security with an optical security layer by generating replicated versions of the input data payload at the input node, and the transmission of each of the replicated versions over a corresponding one of the plurality of links. Moreover, each of the links is composed of multiple wavelengths to propagate optical signals or optical packets, and each of the replicated versions of the data payload may be propagated over a selected one of the wavelengths in each corresponding one of the plurality of links.

Abstract: An optical signaling header technique applicable to optical networks wherein packet routing information is embedded in the same channel or wavelength as the data payload so that both the header and data payload propagate through network elements with the same path and the associated delays. The technique effects survivability and security of the optical networks by encompassing conventional electronic security with an optical security layer by generating replicated versions of the input data payload at the input node, and the transmission of each of the replicated versions over a corresponding one of the plurality of links. Moreover, each of the links is composed of multiple wavelengths to propagate optical signals or optical packets, and each of the replicated versions of the data payload may be propagated over a selected one of the wavelengths in each corresponding one of the plurality of links.

Abstract: An optical signaling header technique applicable to optical networks wherein packet routing information is embedded in the same channel or wavelength as the data payload so that both the header and data payload propagate through network elements with the same path and the associated delays. The technique effects survivability and security of the optical networks by encompassing conventional electronic security with an optical security layer by generating replicated versions of the input data payload at the input node, and the transmission of each of the replicated versions over a corresponding one of the plurality of links. Moreover, each of the links is composed of multiple wavelengths to propagate optical signals or optical packets, and each of the replicated versions of the data payload may be propagated over a selected one of the wavelengths in each corresponding one of the plurality of links.

Abstract: A communications network has a plurality of nodes interconnected by an optical transmission medium. The transmission medium is capable of a carrying a plurality of wavelengths organized into bands. A filter at each node for drops a band associated therewith and passively forwards other bands through the transmission medium. A device is provided at each node for adding a band to the transmission medium. Communication can be established directly between a pair of nodes in the network sharing a common band without the active intervention of any intervening node. This allows the network to be protocol independent. Also, the low losses incurred by the passive filters permit relatively long path lengths without optical amplification.

Abstract: A communications network has a plurality of nodes interconnected by an optical transmission medium. The transmission medium is capable of a carrying a plurality of wavelengths organized into bands. A filter at each node for drops a band associated therewith and passively forwards other bands through the transmission medium. A device is provided at each node for adding a band to the transmission medium. Communication can be established directly between a pair of nodes in the network sharing a common band without the active intervention of any intervening node. This allows the network to be protocol independent. Also, the low losses incurred by the passive filters permit relatively long path lengths without optical amplification.

Abstract: An apparatus for positioning an end effector and associated position controller. The apparatus comprises a plurality of bimorph members, generally elongated in shape, that are coupled end-to-end. In one embodiment, each bimorph member includes a pair of elongated piezoelectric bimorph elements that cause a localized deformation in the bimorph member when driven with an input voltage. Accordingly, each bimorph member can be caused to bend in opposite directions, as well as twist, depending on its drive voltages. In one configuration, four bimorph members are connected end-to-end, with the last bimorph member operatively coupled to the end effector, providing a five-degree of freedom positioner. A multi-channel position controller that provides a pair of correlative feedback loops for each channel is used to generate appropriate drive voltages based on a global feedback signal and a local feedback signal corresponding to a measured position of each channel's corresponding piezoelectric bimorph element.

Abstract: Optical transmission being performed by frequency modulating frequency-division-multiplexed multi-channel signals as a single unit, distortion that is caused by a ripple-shaped group delay deviation in a transmitter 2, a receiver 4 and an optical link 3 is reduced by providing a level adjuster 2a for adjusting the level of frequency-division-multiplexed multi-channel signals input to the FM modulator 2b, and by increasing the input level of multi-channel signals to the FM modulator 2b by level adjusting means 2a to enlarge the bandwidth of FM signal, in the case where the number of channels is small.

Abstract: An object of this invention is to improve transmission characteristics in WDM transmission. An optical transmitter (10) wavelength-multiplexes signal lights of wavelengths &lgr;1 through &lgr;n and outputs them onto an optical transmission line (12). Optical powers of the signal lights of the respective wavelength &lgr;1 through &lgr;n are identical or become smaller proportional to the wavelength. One repeater span of the optical transmission line (12) is composed of an optical fibers (20, 22) and an optical amplifier (24), and a gain equalizer (26) is dispersed every several repeater spans. The optical amplifier (24) in the repeater span amplifies each signal light so that optical power of a signal on the shorter wavelength side becomes smaller than that of a signal on the longer wavelength side. The gain equalizer (26) equalizes optical powers of the respective signal lights.

Abstract: A method and apparatus is provided that yields improved performance of both single channel and WDM long-distance optical transmission systems by synchronously modulating of the transmitted signal's amplitude. An amplitude modulator receives an optical signal onto which data has been modulated at a predetermined frequency. The modulator re-modulates the amplitude of the optical signal in a continues fashion with a waveform that is periodic, whose fundamental frequency is equal to the same predetermined frequency at which the data is modulated onto the optical signal. The resulting signal (which is neither a pure NRZ or RZ signal) is more tolerant to the distortions usually found in lightwave transmission systems, thus giving superior transmission performance.

Abstract: The synchronous digital communications system according to the invention serves to transmit electric signals optically. The electric signals to be transmitted are converted from electrical to optical form (E/O1, E/O2, E/On) and then transmitted using wavelength division multiplexing (WDM) or dense wavelength division multiplexing (DWDM). A synchronization manager and a connection manager are provided. The synchronization manager is adapted to configure dedicated optical synchronization links. The connection manager is adapted to configure switched optical communication links from a pool of wavelengths, taking account of the dedicated synchronization links only. This has the advantage that independently of the switched communication links, synchronization is constantly ensured throughout the system. Each network element (NE1, NE2, NE3) has at least one interface unit that is reserved for synchronization and that continuously receives signals at the wavelength (&lgr;1) reserved for synchronization.

Abstract: An interleaver comprises a serial array of optical elements to which a multichannel, continuous spectrum, composite signal is input and two multichannel, non-continuous spectrum, composite signals are output. Two embodiments are disclosed. One such embodiment provides output composite signals which are spectrally symmetric in that each such non-continuous spectrum contains the same number of channels albeit of alternating center wavelengths. The other such embodiment provides output composite signals which are spectrally asymmetric in that each such non-continuous spectrum contains either a different number of channels or an equal number of channels of narrower or wider passband. Each of the preferred embodiments comprises an array of optical elements which split the input composite signal into components of different polarization states, selectively add phase shifts to some of these components and recombine them a number of times.

Abstract: A method for communicating data over a network having a plurality of nodes thereupon is discussed. A time slot clock signal is transmitted from one node of the plurality of nodes to other nodes of the plurality of nodes. After each of the other nodes of the plurality of nodes receives the time slot clock signal, the time slot clock signal is recalculated to achieve an integer number of slots on the network. The recalculated time slot clock signal is transmitted from the one node of the plurality of nodes to the other nodes of the plurality of nodes.

Abstract: The synchronous digital communications system according to the invention serves to transmit electric signals optically. The electric signals to be transmitted are converted from electrical to optical form (E/O1, E/O2, E/On) and are transmitted using wavelength division multiplexing (WDM) or dense wavelength division multiplexing (DWDM). At least one optical connection is configured as a nonswitched connection using at least one wavelength per transmission section between optical network elements or optical and electrical network elements, and serves to transmit synchronization and information signals. This has the advantage that independently of the switched communication links, synchronization is constantly ensured throughout the network. Each network element (NE1, NE2, NE3) has at least one interface unit that is reserved for synchronization and that continuously receives signals at the wavelength (&lgr;1) reserved for synchronization.

Abstract: A method and apparatus are disclosed for terminating optical links in an opticalnetwork based on performance requirements. The present invention forces the termination of the received optical signals at each node only on the protection ring and does not force termination on the working ring, unless necessary to satisfy performance requirements. A signal on an end-to-end light path on the working ring is terminated only when required by engineering rules, such as signal-to-noise requirements. Specifically, the present invention does not force terminate an end-to-end light path on the working ring at a given node (or on a link between two nodes) unless the signal will fail to meet certain criteria, such as a minimum optical signal-to-noise ratio, at the next node.

Abstract: A multichannel WDM transmission system incorporates a plurality of WDM optical sources with stabilized wavelengths and light intensity. Efficient stabilization of these characteristics is achieved by modulation of WDM sources by distinguishing low frequency electrical signals in a range between 1 and 4 kHz and modulation depth in a range between 1% and 5% that are used as WDM source identifiers. After the modulated outputs of the WDM sources are multiplexed and filtered, a Fourier transform of total light intensity may be obtained. Digital feedbacks provide stabilization of both the wavelength and light intensity of each WDM optical source.

Abstract: To diminish the risk of interruption of traffic in a submarine optical cable system in the region of the shore where damage is most likely to occur, the landing-stage of the system has duplicated spaced-apart cables between a submerged branching unit and an onshore submarine line terminal endstation. Various changeover modes are disclosed, including those where both cables are coupled to signals at all times and changeover is accomplished by blocking amplifiers.

Abstract: A free space communication system includes first and second terminals, and the first terminal includes a transmitter to transmit an input signal. The transmitter has plural laser sources, at least one optical delay line and a telescope. Each laser source modulates the input signal onto a wavelength that is distinct from a wavelength of each other laser source. The plural laser sources include a first laser source and at least one other laser source, and the at least one optical delay line is coupled to a respective output of the at least one other laser source. The telescope projects an output of the first laser source and an output of each of the at least one optical delay line toward the second terminal. Alternatively, a free space communication system includes first and second terminals, and the first terminal includes a transmitter to transmit an input signal. The transmitter has at least one electrical delay line, plural laser sources and a telescope.

Abstract: An optical transmission system accomplishes optical transmission to a long distance by combining a multiplexing line terminal with optical amplifiers, linear repeaters, and regenerators with optical amplifiers combined together. The system also accomplishes the optical transmission to a short distance by directly connecting the linear terminals therebetween, with an electric-to-optic converter replaced by an electric-to-optic converter having a semiconductor amplifier, with an optic-to-electric converter by an optic-to-electric converter having an avalanche photodiode as light receiver, an with no use of any optical booster amplifier and optical preamplifier in the multiplexing line terminal. With these, the optical transmission system can be easily constructed depending on the transmission distance required.

Abstract: A system to adapt the MAC rules of the IrLAP specification to accomodate various IR transceiver devices with media sense utilizes an IrDA protocol stack having a series of layers including: IR Protocol OSI Model Layers Transaction Service 3. Link Management Protocol Network Connection-less LSAP; LMP Connection-less data. 2. Link Access Protocol Data Link Connection-less data; LAP Framing: Rx & Tx; MAC. 1. Connectivity Physical IrDA-SIR, where LSAP is the Link Service Access Point. This kind of protocol stack can be applied to a very large variety of devices, such as, remote controllers with feedback for tuners; can be used for data transactions by request, e.g., pager reporting of received numbers; and is applicable to data acquisition systems, such as, portable GPS reporting of changes of location and medical systems.

Abstract: A SONET framer with multiple clock-crossing capability for use in an optical cross-connect system. The input stage of the cross-connect includes a framer ASIC that performs both frame alignment of multiple data streams and retimes them with a system clock at a same frequency. The ASIC processes multiple clocks from PLL's and retimes the data with the system clock at the same frequency. The present invention nests the clock crossing function in the frame alignment function in order to align all the incoming data streams with the system clock. Advantages include reduced chip area and reduced power consumption.