Abstract: An optical space communications device includes a transmitter circuit which assigns an idle code indicating that the device is transmitting no data so that the idle code differs from an idle code for another device and which, when the transmitter circuit continuously transmits such idle codes, inserts, between the idle codes, a random code having a different random pattern from a pattern of the idle codes. Thus, light from another device is distinguished from stray light based on the idle codes. A disconnection of the other device is reliably detected. The insertion of random codes reduces effect of crosstalk jitter.

Abstract: A network is protected against interruption of service while one or more faulty switches or optical fiber transmission lines are repaired or replaced, by an interconnecting configuration of small N×N optical input/output switches, where N is 2 or greater than 2. The switches are configured among protection and working transmission lines. The small number of fibers for each switch improves repair and installation connection reliability and permits configurations that flexibly meet differing requirements. Also the fault is monitored with a fault check signal.

Abstract: A light emitting section outputs an optical signal having an intensity corresponding to a transmission timing signal, the optical signal modulated based on a radio transmission signal. A received photocurrent detection section detects an intensity of an optical signal received by a light receiving section. In accordance with the detected intensity, a high frequency amplification section amplifies the output signal of the light receiving section, and a transmission timing signal reconstruction section reconstructs the transmission timing signal.

Abstract: An optical transceiver is equipped with at least one coupling lens which condenses reception signal light from an optical medium and condenses transmission signal light to the optical medium, an optical plate which passes the reception signal light and reflects the transmission signal light, a light receiving element which receives the reception signal light passed through the optical plate, and a light emitting element which transmits the transmission signal light so as to be reflected by the optical plate, wherein an emission port of the transmission signal light of the light emitting element is arranged at a position to enable the transmission signal light from the light emitting element to form an image in the optical medium via the optical plate and the coupling lens, and wherein the emission port of the transmission signal light of the light emitting element is arranged in a direction that makes the incident angle formed on the optical plate by the beam center line of the transmission signal light trans

Abstract: The invention relates to an intelligent network element for optical networks, comprising: at least one back-plane with a plurality of electrical transmission lines running across the back-plane and a plurality of electrical terminals connected to the transmission lines; a plurality of line-card slices having electrical terminals, each line-card slice being attached to the back-plane directly or in the form of a plug-in module such, that the electrical terminals of the line-card slice are electrically connected to selected ones of the terminals of the back-plane, with at least one of the line-card slices comprising at least one optical receiver for receiving of optical signals from the network and at least one opto-electrical converter integrated in or optically connected to the optical receiver with electrical terminals, and at least one of the line-card slices comprising at least one optical transmitter for transmitting of optical signals to the network and at least one electro-optical converter integrate

Abstract: A multiband wavelength multiplexed optical device for bidirectional communication over one light path. The device may use dichroic filters or reflectors, or other mechanisms for wavelength or bandwidth separation or discrimination of sent or received light signals. It may have a multitude of light sources and detectors for sending and receiving light signals such as those for optical-based communications, controls and so forth. For instance, the optical device may be utilized in transceiver systems.

Abstract: The invention pertains to an electro-optical connector module comprising a connection part, at least one optical transmitter circuit and/or optical receiver circuit and at least one electro-optical converter for respectively converting electrical signals into optical signals or vice versa. The module further comprises at least two substantially flat and substantially parallel electrically insulating sheets on which the transmitter circuit and/or receiver circuit and the converter are mounted. It is preferred that the connector module according, comprises at least one optical transmitter circuit, at least one optical receiver circuit and at least two electro-optical converters for respectively converting electrical signals into optical signals and vice versa, wherein the optical transmitter circuit and a first converter are mounted on a first sheet and the optical receiver circuit and a second converter are mounted on a second sheet.

Abstract: An optical communication apparatus in which bidirectional communication may be made over a sole optical fiber. A light emitting device (132) radiates light through an optical system (133) to an optical fiber (76). The light transmitted from the optical fiber (76) is received over optical system (133) by a light receiving device (136). In the optical system (133), such a relationship S?2QN?M>S/2Q?N is set, where M is the light volume of the stray light emitted, Q is the value of a Q-value representing the communication quality as required, S is the light volume of a received signal from a communication partner and N is the sum total of the Gaussian noise.

Abstract: Wavelength interleaving cross-connects pass a first optical signal including a first set of optical frequencies in a first direction and a second optical signal including a second set of optical frequencies in a second direction. In one embodiment, the first optical signal, when input to a first input/output (I/O) port, is routed from the first I/O port to a third I/O port. The first optical signal, when input to a fourth I/O port, is routed from the fourth port to a second I/O port. The second optical signal, when input to the second I/O port, is routed from the second I/O port to the third I/O port. The second optical signal, when input to the fourth I/O port, is routed from the fourth I/O port to the first I/O port. Thus, by coupling an optical device (e.g., amplifier, filter) between the third port and the fourth port, the optical device can be used for bi-directional communications thereby reducing the number of devices required for a bi-directional optical network architecture.

Abstract: An optoelectronic transceiver including an optoelectronic transmitting unit disposed along an optical axis and having a radiation-emitting layer region and an active radiation-sensitive layer region. The optoelectronic transceiver further including an optoelectronic receiving unit disposed along the optical axis and is disposed in bridge-like fashion above the optoelectronic transmitting unit. The optoelectronic receiving unit having an active radiation-sensitive layer region disposed perpendicular to the optical axis and located in a thin membrane, which is disposed immediately in front of the radiation-emitting layer region of the optoelectronic transmitting unit, and a radiation-emitting layer region.

Abstract: A divider/combiner unit combines RF signals, then converts the combined signal into an optical signal and sends it over an optical fiber. N radio access units each convert the optical signal received from the optical fiber into an RF signal and transmits it from an antenna, and each radio access unit converts an RF signal received by the antenna into an optical signal and sends it over an optical fiber to the divider/combiner unit. The divider/combiner unit converts the received optical signal into RF signals and outputs them. This system is operated as plurality of communication systems in common to them in correspondence to a plurality of input/output terminals of the divider/combiner unit.

Abstract: A method of transmitting and rapidly recovering a burst of data without first having to establish a timing or phase lock. The signals are transmitted as modified Manchester coded signals having pulse transitions at a clocking pulse rate which is a multiple of the clocking pulse rate at which the signals are originally generated, and wherein the MOOSE coded signal is modified by ON-OFF keying.

Abstract: A bi-directional optical transmission system according to the present invention provides transport of x optical channels over n nodes. The system supports two-way transport of the x channels over a single fiber connecting each of the nodes in sequence. The system is advantageous in that only two optical transmission bands are utilized in order to achieve minimal loss in the separation of bands. The use of only two bands permits the utilization of low-loss wide band thin film optical filters to combine and separate the signals at each node. A reflection port of this filter is used to carry oppositely directed signals of the second band from the bi-directional fiber to an optical amplifier for the second band. An alternate arrangement of the optical filters in the two separate bands is chosen to maximize the optical performance of the overall system and significantly reduce insertion losses.

Abstract: A bi-directional communication assembly is provided with commonly available optoelectronic components in a compact package. Diplex functionality is achieved by orienting the receiving detector at an angle with respect to the transmitting beam. An interference coating inside the detector, on the detector surface, or on a surface in intimate contact with the detector, reflects the transmitted beam while simultaneously allowing the receiving beam to pass through the coating to the light absorbing region. The combined function of the receiving detector, providing advantages of a common beam path and close proximity of the components, enable a compact package that can be placed within the space usually occupied by the transmitter light source alone.

Abstract: The present invention provides an improved full-duplex optical communications system. The system includes: at least one office, where the at least one office provides a plurality of channels, the plurality of channels comprising a plurality of signal channels and a plurality of continuous wave (CW) channels; at least one optical add/drop multiplexer (OADM) optically coupled to the at least one office; and a subscriber premises optically coupled to the at least one OADM, where at least one of the plurality of signal channels and at least one of the plurality of CW channels are dropped from the plurality of channels to the subscriber premises by the at least one OADM, where the subscriber premises modulates the dropped at least one of the plurality of CW channels, where the modulated at least one of the plurality of CW channels is added to the plurality of channels by the at least one OADM.

Abstract: Methods and apparatus for multiplexing and demultiplexing optical signals. An interleaver having a modified Mach-Zehnder interferometer as a first stage is used as a wavelength division multiplexer. This first stage is combined with one or more cascaded stages, each having a beam splitter and an optical delay element. A light beam including a number of signals at different wavelengths is received. The beam is split such that approximately half of each signal is contained in one of two sub-beams. One of the two sub-beams passes through a delay element, which provides a phase shift. The two sub-beams are recombined and split again. Each wavelength adds constructively or destructively in the new sub-beams such that the signals are separated—some wavelengths are in one of the new sub-beams, some are in the other. One of these sub-beams is delayed, and the two are combined and split again, improving the separation.

Abstract: A compact enclosure for interchangeable SONET multiplexer cards and a method for using the same. The present invention further provides a compact enclosure for receiving one or more reduced size SONET multiplexer cards having front panel access to electrical and optical connectors, along with other cards such as DS1-DS3 multiplexer cards and wave division multiplexing cards, which is adapted for use in a reduced size enclosure, and a method for using the same.

Abstract: The invention relates to a bidirectional transmitting and receiving device having a transmitting component having an emission area of a first size, that emits light at a first wavelength, and a receiving component having a receiving area of a second size, that receives light at a second wavelength. The device further includes coupling optics for coupling a light between the transmitting component and the receiving component on the one hand and an optical waveguide that is to be coupled thereto on the other hand.

Abstract: A PON (Passive Optical Network) and method employing CDMA for upstream communications to avoid complicated systems such as Machine Access Control. The downstream communications are broadcast in a non-CDMA protocol such as TDM.

Abstract: Described is a transmission system (10) for transmitting an information signal (21) via a plurality of subchannels from a transmitter (12) to a receiver (16). The transmitter (12) comprises a demultiplexer (20) for demultiplexing the information signal (21) into a plurality of information subsignals (23). The transmitter (12) further comprises a channel encoder (8) for encoding the information subsignals (23) into encoded information subsignals (25). Each encoded information subsignal (25) is transmitted via one of the subchannels to the receiver (16). The receiver (16) comprises a channel decoder for successively decoding the received encoded information subsignals. The transmission system (10) is characterized in that the demultiplexer (20) is arranged for demultiplexing the information signal (21) into a plurality of partly overlapping information subsignals (23) comprising shared and non-shared information elements.

Abstract: A method of full-duplex electromagnetic communication wherein a pair of data modulation formats are selected for the forward and return data links respectively such that the forward data electro-magnetic beam serves as a carrier for the return data. A method of encoding optical information is used wherein right-hand and left-hand circular polarizations are assigned to optical information to represent binary states. An application for an earth to low earth orbit optical communications system is presented which implements the full-duplex communication and circular polarization keying modulation format.

Abstract: The present invention is directed to a bi-directional optical monitor interconnect. The bi-directional monitor interconnect of the present invention includes an optical conductor with a first and second end. Disposed on the first end of the optical conductor is a first optical communication device and a first optical receiving device. Disposed on the second end of the optical conductor is a second optical communication device and a second optical receiving device. The first and second optical communication devices are capable of transmitting data over an optical connection. The first optical communication device is suitable for communicating via a first wavelength and the second optical communication device is capable of communicating over a second wavelength. The first receiving device is capable converting the second wavelength into electrical signals and the second receiving device is capable of converting the first wavelength into electrical signals.

Abstract: An optical transmission system is provided in which the signals are transmitted at different wavelengths between terminals of a transmission network and only those signals are regenerated whose quality parameters require regeneration. A management system, when deciding about the location of regeneration, takes the design and the properties of the transmission network including the existing regeneration possibilities and the possible routing into consideration.

Abstract: A method and system for multi-level power management in an optical network is provided. They include three levels of power equalization. The first level of power management equalizes the powers of channels in a band of channels. The second level of power management equalizes the average powers of bands of channels on a fiber. The third level of control equalizes the powers of bands of channels on working and protection fibers for a path in the optical network. As a result, this multi-level power management in the network provides a dynamic, automatic method for the network to adjust to changing operating conditions and configurations and to maintain relatively stable network powers. Each level of power management may be implemented jointly or independently, and operates autonomously so that, for example, one modification comprises continuous first level control and only periodic second level control.

Abstract: To support interleaving of optical channels and to provide sufficient isolation between such interleaved channels, a circulator (60-62) receives, on an optical fiber (16-18), a broadband signal containing a plurality of adjacent channels. The circulator selectively routes the broadband signal through a filter (64, 66) to isolate, on an individual basis, at least one desired channel. A filtered signal, corresponding to the at least one desired channel, is then output from the filter (64-66) and reflected back into the filter by a mirror (68-70) such that the at least one desired channel is subjected to a second filtering process that further improves isolation of the at least one desired channel. Following this second filtering process, the at least one desired channel is applied to the circulator (60-62) for re-inserting into the optical fiber (16-18), as illustrated in FIG. 6.

Abstract: An all-optical reference node in an optical communication network detects the power in each channel and, using an optical power monitor and a series of voltage-controlled attenuators connected in a feedback loop, adjusts the power in each channel so as to equalize the power in all channels. The optical reference node also removes amplified spontaneous emissions. Likewise, the power of each channel added at an add/drop node is equalized to the power in the channels that pass through the add/drop node. Thus the power in the respective channels is equal through the network, and amplifiers located at intervals on the network are not driven into saturation as they attempt to amplify weaker signals. According to another embodiment, a simplified optical communication network contains only passive components.

Abstract: An optical add/drop multiplexing (OADM) apparatus and method are disclosed for detecting pilot tones, removing ghost tones, and re-inserting pilot tones on WDM signals in an optical network. The OADM apparatus comprises a smart processing and control unit (PCU) for detecting pilot tones used for channel identifications, including identifying and removing ghost tones associated with respective optical channels, and re-inserting the processed pilot tones into the respective optical channels. The OADM apparatus and method may incorporate digital PCU or analog PCU for processing pilot tones and removing ghost tones.

Abstract: The invention concerns a method for call or connection admission control, in a telecommunication system in particular of the digital type. For each current connection and each requested connection, the method consists in determining a parameter which depends on the bandwidth and the power of the connection and in summing the parameters for all the connections. The requested connection is granted if the sum of said parameters does not exceed a predetermined threshold. In one embodiment, the parameter for each connection is homogeneous with a power level. The parameter is, for example, the product of a terminal or a base station power by a dimensionless coefficient proportional to a bandwidth. The invention is applicable to a telecommunications system wherein terminals (141, 142, 143) communicate with a base station (12), for example via satellites.

Abstract: The present invention provides an optical demultiplexer and an optical multiplexer the transmission characteristics of which are unlikely to be affected by fabrication errors and which have small group delay dispersion. A cross output port (X-OUT) of a second optical demultiplexer element (DEMUX) is selected, and a through output port (T-OUT) of a third DEMUX is selected. A T-OUT of a first DEMUX has a passband equal to the X-OUT of the second DEMUX, and a X-OUT of the first DEMUX has a passband equal to the T-OUT of the third DEMUX. The T-OUT of the first DEMUX has group delay characteristics opposite to those of the X-OUT of the second DEMUX, and the X-OUT of the first DEMUX has group delay characteristics opposite to those of the T-OUT of the third DEMUX.

Abstract: A device for interactively transmitting optical signals in a first wavelength and receiving optical signals in a second wavelength both through a one-core optical fiber, includes a first photodiode that converts a received optical signal into a first electric signal, a second photodiode that converts an optical signal into a second electric signal, a first amplifier connected between the second light-electricity signal converter and the coherent light remover, a second amplifier connected to the second light-electricity signal converter, and a differential amplifier that subtracts the second electric signal from the first electric signal.

Abstract: An optical network element comprising a plurality of subscriber line connections, a WDM unit having a plurality of WDM channel connections, a plurality of subscriber line interface cards and a plurality of trunk line interface cards for optical interfacing between the subscriber line connections and the WDM channel connections, and a switch arranged, in use, in a manner such as to be capable of switching transmission directions between the WDM channel connections and individual ones of the subscriber line connections by suitable switching of an optical path configuration between transmitter ports and receiver ports of the subscriber line interface cards and the WDM channel connections.

Abstract: A method of transmitting bidirectional telephony communication signals on a single optical fiber. The bidirectional signals are transmitted in one direction as NRZ coded signals at a first clocking pulse rate, and in the other direction as modified a hybrid form of ON-OFF keying coded signals having pulse transitions at a second clocking pulse rate which is a multiple (preferably eight times (8×)) of the first clocking pulse rate, wherein the modified Manchester coded signal is modified by ON-OFF keying.

Abstract: An optical communication system is formed by connecting a base station to user stations. Each user station has a transmitting section for upstream communication. The base station has a light source which supplies transmission light used for upstream communication.

Abstract: Disclosed is a bidirectional optical link and method to facilitate bi-directional optical communications with a single optical fiber. Briefly described, the bi-directional optical link comprises a thin film detector having an upper surface facing a predetermined direction to receive incident light. Also, the link includes a thin film emitter stacked over the upper surface and oriented to direct a beam of light toward the predetermined direction. The thin film detector is relatively wide and flat, where the thin film emitter can be placed on the thin film detector while occluding only a portion of the thin film detector. Thus, the thin film detector can receive incident light from a single optical fiber facing the emitter/detector from the predetermined direction while at the same time emitting a beam of light into the same single optical fiber.

Abstract: The bidirectional dispersion compensator comprises at least one circulator (Z,Z1,Z2,Z4) and at least one filter-coupler element (F1, etc.). The optical signals (S1,S2) that are emitted in opposite directions are merged and sent to a compensation fiber (LK,LK1, etc.) together, are reflected at the ends of this fiber, and are forwarded in the respective directions of transmission as dispersion-compensated optical signals (SK1 and SK2).

Abstract: A method of increasing capacity on a long-haul undersea cable system having at least one optical fiber, said method comprising interleaving counter-propagating forward-propagating and backward-propagating signals in forward and backward channels on a common optical fiber, wherein the wavelength offset between said forward and backward channels is typically half of the channel spacing of co-propagating signals.

Abstract: A method of splitting an optical data signal starting with an optical data signal split into n equal data sub-signals, and an optical binary auxiliary signal with the same bit rate and phase is added to each optical data sub-signal. Each nth bit of the optical binary auxiliary has a higher level, with the phases of each of the n optical auxiliary signals showing a relative displacement of one bit. As a result, n aggregate signals are generated, each of which is fed to a decision-maker. A decision-maker threshold is set above the amplitude of the data sub-signal and below the amplitude of the aggregate signal. Each decision-maker, therefore, emits an electrical data signal with 1/n times the bit rate of the data signal.

Abstract: Disclosed is a broadcast/communication unified passive optical network system.

Abstract: An optical wireless transceiver for communicating broadband signals through free space includes an input, a regenerator, a splitter and a plurality of lasers in transmitter modules. A very fast (low f-number) optical receiver module includes a reflector aligned with an input aperture. A photodiode receives the signal from the reflector for subsequent demodulation. A background rejection filter is disposed between the reflector and the photodiode at the focal point of the mirror. The transceiver provides signal regeneration and switchable data rates. Connections are made to optical or electrical digital inputs and outputs bearing signals of various protocols. The plurality of lasers includes adjustable-beamwidth collimating lenses. An efficient high-current, high power laser driver capable of modulating a laser between 100 and 1500 mA at data rates greater than 10 Mbits/sec is provided. A highly efficient thermoelectric cooler operates to cool the laser diode, or other components requiring cooling.

Abstract: The invention relates to an intelligent network element for optical networks, comprising:

Abstract: The present invention aims to provide a WDM optical communication system that can arrange efficiently optical signals of a plurality of bit rates at different wavelength spacing.

Abstract: A prism 11 is formed which has a first face 11a opposing an end face of an optical fiber 21 and receiving a light-to-be-received from the optical fiber, second and third faces 11b and 11c adjoining opposite ends of the first face 11a at right angles and opposing each other, a fourth face 11d for reflecting the light-to-be-received from the face 11a toward the face 11b, and a fifth face 11e reflecting a light-to-be-transmitted as projected from a light source through the face 11c toward the face 11a. First and second light-to-be-received converging lenses 12 and 13 are disposed on the faces 11a and 11b of the prism 11 and first and second light-to-be-transmitted converging lenses 14 and 15 are disposed on the faces 11a and 11c. The tilt angles &bgr;1 and &bgr;2 of the faces 11d and 11e with respect to the optical fiber axis 21a are less than 45°.