Abstract: A wavelength selective switching device comprises a plurality of input paths for receiving optical signals, a plurality of output paths for emitting the optical signals, and a switching unit for selectively directing the optical signals from the input paths to the output paths. The switching unit comprises a reflective area adapted to be concurrently illuminated by a first optical signal from a first input path among the plurality of input paths, and by a second optical signal from a second input path among the plurality of input paths, the second input path being different from the first input path, and to concurrently direct the first optical signal to a first output path among the plurality of output paths and the second optical signal to a second output path among the plurality of output paths, the second output path being different from the first output path. Said first output path and said second output path are spatially separated by said first input path and said second input path, or vice-versa.

Abstract: Disclosed herein is a method of transmitting data in an optical network (10, 100) from a first location to a second location, as well as a corresponding receiver unit and transceiver.

Abstract: The present invention relates to adding and dropping signals in a node of an optical network, wherein the node includes a reconfigurable optical add/drop multiplexer (ROADM). The reconfigurable optical add/drop multiplexer (ROADM) comprises output ports and at least one add port connectable to at least one line interface of the network and adapted to receive a modulated optical signal from the line interface. Selection units are connected to one of said add ports and adapted to forward the respective signals to a selected output terminal. A plurality of broadcast units is adapted to broadcast signals forwarded by the selection. Then a multiplexing and selecting device or apparatus selects and multiplexes the optical signals broadcast via broadcast unit output terminals into a plurality of wavelength-division multiplexing (WDM) optical signals and forwards the same to output ports of the reconfigurable optical add-drop multiplexer (ROADM).

Abstract: A wavelength selective switching device comprises a plurality of input paths for receiving optical signals, a plurality of output paths for emitting the optical signals, and a switching unit for selectively directing the optical signals from the input paths to the output paths. The switching unit comprises a reflective area adapted to be concurrently illuminated by a first optical signal from a first input path among the plurality of input paths, and by a second optical signal from a second input path among the plurality of input paths, the second input path being different from the first input path, and to concurrently direct the first optical signal to a first output path among the plurality of output paths and the second optical signal to a second output path among the plurality of output paths, the second output path being different from the first output path. Said first output path and said second output path are spatially separated by said first input path and said second input path, or vice-versa.

Abstract: The present invention relates to adding and dropping signals in a node of an optical network, wherein the node includes a reconfigurable optical add/drop multiplexer (ROADM). The reconfigurable optical add/drop multiplexer (ROADM) comprises output ports and at least one add port connectable to at least one line interface of the network and adapted to receive a modulated optical signal from the line interface. Selection units are connected to one of said add ports and adapted to forward the respective signals to a selected output terminal. A plurality of broadcast units is adapted to broadcast signals forwarded by the selection. Then a multiplexing and selecting device or apparatus selects and multiplexes the optical signals broadcast via broadcast unit output terminals into a plurality of wavelength-division multiplexing (WDM) optical signals and forwards the same to output ports of the reconfigurable optical add-drop multiplexer (ROADM).

Abstract: A photonic cross-connect arrangement is presented which is able to cope with the transmission of super-channels, wherein complete super-channels are dropped and added to change a direction of transport. At least a cyclic filter is used in a drop-branch of a cross-connect for dividing a super-channel into sub-channels and/or at least a further cyclic filter is used in an add-branch to configure a super-channel.

Abstract: Safety and power control arrangement and method for optical communication apparatus, where a first circuit pack emitting an optical signal (OS1) and at least a second and a third circuit pack (2, 3) are connected in series via optical fibers (4, 5). A power monitor (26) connected to an output (27) of the at least second circuit pack (2) reduces the signal power (PW2) output from the second circuit pack (2) to a pre-determined safe value if a loss-of signal monitor (34) of a next circuit pack (3) forwards a loss-of-signal control signal (LOC3). The advantage is that the maximum allowable value is achieved at the input of an interrupted fiber section and the non-interrupted circuits can still receive the optical signals with a reasonable power level.

Abstract: A photonic cross-connect arrangement is presented which is able to cope with the transmission of super-channels, wherein complete super-channels are dropped and added to change a direction of transport. At least a cyclic filter is used in a drop-branch of a cross-connect for dividing a super-channel into sub-channels and/or at least a further cyclic filter is used in an add-branch to configure a super-channel.

Abstract: A wavelength division multiplexer terminal with a multiplexer arrangement with a first switching matrix, and a demultiplexer arrangement with a second switching matrix allows flexibility for connection transceivers to ports of the wavelength division multiplexer and wavelength division demultiplexer respectively. Optical monitoring receivers are connected upstream the wavelength division multiplexer and downstream the wavelength division demultiplexer for managing and supervising connections.

Abstract: A photonic cross-connect includes a plurality of ingress WS-switches with drop outputs outputting WDM drop signals including odd channels and a plurality of egress WS-switches for receiving WDM add signals including add channels. Wavelength selective elements in a drop path and in an add path comply with a double frequency spacing and about a double bandwidth of the ingress WS-switches or egress WS-switches. If both odd and even channels are dropped and added, separate add and drop paths are provided for the odd and for the even channels.

Abstract: Safety and power control arrangement and method for optical communication apparatus, where a first circuit pack emitting an optical signal (OS1) and at least a second and a third circuit pack (2, 3) are connected in series via optical fibers (4, 5). A power monitor (26) connected to an output (27) of the at least second circuit pack (2) reduces the signal power (PW2) output from the second circuit pack (2) to a pre-determined safe value if a loss-of signal monitor (34) of a next circuit pack (3) forwards a loss-of-signal control signal (LOC3). The advantage is that the maximum allowable value is achieved at the input of an interrupted fiber section and the non-interrupted circuits can still receive the optical signals with a reasonable power level.

Abstract: A wavelength division multiplexer terminal with a multiplexer arrangement with a first switching matrix, and a demultiplexer arrangement with a second switching matrix allows flexibility for connection transceivers to ports of the wavelength division multiplexer and wavelength division demultiplexer respectively. Optical monitoring receivers are connected upstream the wavelength division multiplexer and downstream the wavelength division demultiplexer for managing and supervising connections.

Abstract: According to the invention, a very narrow-band transfer signal (LS) is generated by serially connecting a frequency modulator (2) and an amplitude modulator (4). The frequency modulator (2) is operated at a modulation index which at least largely suppresses the carrier signal (TS) while the amplitude modulator (4) suppresses the broadband portion of the spectrum by fading out the transfer signal (LS) during frequency-shift keying.

Abstract: According to the invention, a very narrow-band transfer signal (LS) is generated by serially connecting a frequency modulator (2) and an amplitude modulator (4). The frequency modulator (2) is operated at a modulation index which at least largely suppresses the carrier signal (TS) while the amplitude modulator (4) suppresses the broadband portion of the spectrum by fading out the transfer signal (LS) during frequency-shift keying.

Abstract: A photonic cross-connect includes a plurality of ingress WS-switches with drop outputs outputting WDM drop signals including odd channels and a plurality of egress WS-switches for receiving WDM add signals including add channels. Wavelength selective elements in a drop path and in an add path comply with a double frequency spacing and about a double bandwidth of the ingress WS-switches or egress WS-switches. If both odd and even channels are dropped and added, separate add and drop paths are provided for the odd and for the even channels.

Abstract: A wavelength multiplex signal (WDM1, WDM2) having a plurality of channels is supplied to a wavelength-selective switch (WSS1, WSS2) which has a tunable, optical band rejection filter (TUF1, TUF2) at least one input or output. In addition, a controller is provided which is designed such that before a switching operation by the switch (WSS1, WSS2) a channel to be switched is locked by means of the band rejection filter (TUF1, TUF2), the switching operation is performed and then the channel is unlocked.

Abstract: According to the invention, in add-drop devices of an optical cross-connect device for wavelength multiplex signals, tributary drop signals to be dropped are pre-selected in the drop branch by means of pre-selection elements. Only these signals are amplified, thus reducing the number and/or power of the optical amplifiers. The tributary drop signals are individually selected by means of drop routing elements and adjustable filters. The add branch is created correspondingly.

Abstract: According to the invention, in add-drop devices of an optical cross-connect device for wavelength multiplex signals, tributary drop signals to be dropped are pre-selected in the drop branch by means of pre-selection elements. Only these signals are amplified, thus reducing the number and/or power of the optical amplifiers. The tributary drop signals are individually selected by means of drop routing elements and adjustable filters. The add branch is created correspondingly.

Abstract: In the inventive arrangement, the core layers of two optical waveguides are arranged parallel to one another at a distance and overlap in an overlap region. In the overlap region, at least one of the waveguides comprises a cross-sectional taper. The effect thereof is that a wave guided in one waveguide couples completely over into the other in the overlap region.

Abstract: An optical fiber of the type makes it possible to guide light waves independently of their polarization at 1.55 .mu.m wavelength. The optical layer (12) and semiconductor material (11, 12) adjacent to both flat sides (121, 122) of the layer (12) have a crystal lattice constant (1) less than 1% lower than a determined crystal lattice constant (a1) of InP. In a preferred embodiment of the invention, a superlattic is provided on an InP substrate to widen the InP lattice constants.