Abstract: A device and method for multiplexing or demultiplexing M optical signals, each having a different wavelength ?m. An MMI waveguide has a length such that each optical signal that propagates into the MMI waveguide at an i:th access waveguide, where i?N, and N is greater than or equal to 2, produces N self-images inside the MMI waveguide at a respective distance Im from the access waveguides. Each of M wavelength selective reflectors is arranged near a respective distance Im, wherein the m:th reflector reflects the optical signal carried by the m:th wavelength, where 2?m?M, while being substantially transparent to all other wavelengths. Each of M phase adjustors is arranged relative to a corresponding reflector, wherein the m:th phase adjustor adjusts the phase of the self-images of the optical signal carried by the m:th wavelength to create a single self-image at a selected output access waveguide when reflected by the m:th reflector.

Abstract: An optical add/drop multiplexing (OADM) device includes two MMI structures connected by a MI/MZI waveguide structure comprising a wavelength selector that includes phase shifted Bragg gratings. The OADM multiplexer transmits a wavelength channel selected in advance and reflects all other channels to achieve a drop functionality. Simultaneously, a further channel may be added to the multiplexer at the same side as the channel selected in advance is output. The further channel preferably is centered around the same wavelength as the channel selected in advance. The further channel is transmitted through the Bragg gratings and is superimposed with the other channels to achieve an add functionality.

Abstract: The present invention relates to device for space selective switching of an optical signal from an input access waveguide to a first selected output access waveguide. Said device comprising a multi-mode interference (MMI) waveguide having at a first side a number, N, of accesses for connection of access waveguides. Said MMI waveguide having a length, in light propagating direction, so that an image at the i:th, i?N access waveguide propagating into said MMI waveguide will produce N self-images at a second side opposite to said first side, where N is an integer than 1. Said device further comprises reflective means located in said MMI waveguide close to said second side, arranged to reflect said N self-images towards said first side of said MMI waveguide, and means, arranged at said second side, for adjusting the phase of each of said self-images to create a single self-image at said selected output access waveguide.

Abstract: The present invention relates to device for space selective switching of an optical signal from an input access waveguide to a first selected output access waveguide. Said device comprising a multi-mode interference (MMI) waveguide having at a first side a number, N, of accesses for connection of access waveguides. Said MMI waveguide having a length, in light propagating direction, so that an image at the i:th, i?N access waveguide propagating into said MMI waveguide will produce N self-images at a second side opposite to said first side, where N is an in ter than 1. Said device further comprises reflective means located in said MMI waveguide close to said second side, arranged to reflect said N self-images towards said first side of said MMI waveguide, and means, arranged at said second side, for adjusting the phase of each of said self-images to create a single self-image at said selected output access waveguide.

Abstract: A device for multiplexing or demultiplexing M, M being an integer and greater than or equal to 2, optical signals each having a different wavelength ?m. Said device comprising a multi-mode having at a first side a number, N, of accesses for connection of waveguide having a length, in light propagating direction, so that an image at the i:th, i?N access waveguide propagating into said MMI waveguide will produce N self-images for each of said M wavelengths ?m, at M positions separated in light propagation direction, at first distances lm, lm>lm+1, from said access waveguides where N is an integer greater than or equal to 2, and where each of said positions corresponds to a wavelength.

Abstract: The present invention relates to a device and a method for optical add/drop multiplexing (OADM) and comprises two MMI structures (3, 23) connected by a MI/MZI waveguide structure (13) comprising wavelength selective means (19, 21, 37, 39), in particular phase shifted Bragg gratings or Bragg gratings of lowpass and highpass type in combination, such that the OADM multiplexer transmits a wavelength channel (&lgr;i) selected in advance and reflects all other channels, wherein a drop functionality is achieved. Simultaneously, a further channel (&lgr;j,) may be added to the multiplexer at the same side as the channel selected in advance is output, where said further channel preferably is centered around the same wavelength as the channel selected in advance. The further channel is transmitted through the Bragg gratings and is superimposed with the other channels, wherein an add functionality is achieved.

Abstract: The present invention relates to a device for wavelength selective phase control of a signal at a predetermined wavelength in a wavelength multiplexed optical signal, which comprises an input port for inputting the wavelength multiplexed optical signal, a splitting means for splitting the input wavelength multiplexed optical signal into the signal at the predetermiend wavelength and a signal comprising of substantially the remaining wavelengths in the multiplex, a phase control element for phase control of one of the two splitted signals, a combining device for combining the splitted phase-controlled signal and the other splitted signal in order to achieve a wavelength multiplexed wavelength selectively phase-controlled optical signal, and an output port for outputting the wavelength multiplexed wavelength selectively phase-controlled optical signal. A switch comprising at least one device of said kind and a method for wavelength selective phase control are likewise comprised in the present invention.

Abstract: The present invention relates to a device and a method for wavelength selective filtration of optical wavelength channels. The wavelength selective filter (1) includes one or more wavelength selective add-drop elements (10, 12, 14 and 16) and one or more on-off switches (20, 22, 24 and 26), wherein a first and a second side of the wavelength selective add-drop elements (10, 12, 14 and 16) includes an input and an output, wherein said on-off switches (20, 22, 24 and 26) are disposed between said input and output on the second side of the wavelength-selective add-drop elements (10, 12, 14 and 16), and wherein in the event of more than one wavelength selective add-drop element said elements are interconnected by means of a connecting waveguide between respective outputs and inputs on the first side of respective wavelength selective add-drop elements.

Abstract: The present invention relates to an apparatus and a method for wavelength selective switching of a plurality of optical wavelength channels. The apparatus comprises two MMI waveguides interconnected by at least two Mach-Zehnder waveguide structures arranged in parallel, of which each is arranged to transmit a respective portion of the intensity of said plurality of optical wavelength channels.

Abstract: A device for multiplexing a wavelength multiplexed optical signal (25) comprising at least a first and a second optical wavelength channel centered around respective predetermined wavelengths (&lgr;1, &lgr;2), comprising an MMI coupler (2), at least of the size 2×2, for inputting the wavelength multiplexed optical signal at an input (3) and for splitting the multiplexed signal into components and imaging these at several ports (13-21), Michelson waveguides (27-31) for receiving and transporting the components imaged at the port of the MMI coupler, reflecting means (33-41) for reflecting the components received and transported in the Michelson waveguides back to the ports of the MMI coupler, wherein the MMI coupler is arranged for inputting the reflecting components, and the respective lengths of the Michelson waveguides are adapted so that said MMI coupler combines the components in a manner such that the first and the second optical wavelength channels are imaged substantially at separated outputs (5-1

Abstract: An apparatus for add/drop multiplexing of a wavelength channel multiplex comprises an MMI coupler and MI arm section. The MMI coupler includes a multiplex input, an add channel input, a drop channel output, a multiplex output, and at least four input/output terminals. The MI arm section includes four waveguides, wherein each waveguide is optically connected to a respective one of said input/output terminals of the MMI coupler; and is at least provided with a first phase control element, a reflection grating, a second phase control element, and a wide frequency range reflection means. Further, each of the reflection gratings are provided with a heater means for tuning the respective reflection grating to the wavelength channel to be added/dropped and the wide frequency range reflection means reflect all other channels.

Abstract: The present invention relates to a device and to a method for the wavelength selective filtration of optical wavelength channels. The device includes at least one 3 dB-coupler or at least one Q port circulator (40), where Q≧3, a 1×N WDM-(de)multiplexer (30), where N≧2, N number of waveguides (31, 32, 33, 34, 35, 36, 37 and 38), at least N number of reflection sections (61, 62, 63, 64, 65, 66, 67 and 68) and at least N number of variable optical attenuators (71, 72, 73, 74, 75, 76, 77 and 78). One of the ports on the circulator (40) or on the 3 dB-coupler is connected to a first side of the WDM-(de)multiplexer (30).

Abstract: The present invention relates to an arrangement and to a method for wavelength selecting transmission, said arrangement comprising two N×N MMI waveguides (10 and 20), where N≧2, 2 (N−1) number of lasers (1 and 2) and N-number of Mach-Zehnder waveguides (31, 32, 33, 34 and 35). A first N×N MMI waveguide (10) is coupled with N−1 number of lasers (1) and a free access waveguide (15) on a first side, and N-number of Mach-Zehnder waveguides (31, 32, 33, 34 and 35) of mutually different lengths on a second side. The free access waveguide (15) is coupled with a last port (a15) on the first side of the first MMI waveguide (10). A second N×N MMI waveguide (20) is coupled with said N-number of Mach-Zehnder waveguides (31, 32, 33, 34 and 35) on a second side and N−1 number of lasers 82) and a free access waveguide (21) on a first side, where N−1 number of Mach-Zehnder waveguides (31, 32, 33 and 34) include a trimming section (41, 42, 43 and 44).

Abstract: The present invention relates to an arrangement and a method relating to optical channel equalizers. The channel equalizer includes at least one Q-port direction-dependent router (40), where Q≧3, one N-channel WDM (de)multiplexer (30), where N≧2, N-number of amplifying waveguides (31, 32, 33, 34, 35, 36, 37 and 38), at least N-number of fiber amplifiers (51, 52, 53, 54, 55, 56, 57 and 58), at least N-number of Bragg gratings (61, 62, 63, 64, 65, 66, 67 and 68), at least N-number of variable optical pump laser attenuators (71, 72, 73, 74, 75, 76, 77 and 78), at least one optical splitter (20 and 22) and at least one pump laser (10, 12, 14 and 16) per optical splitter (20 and 22). At least one of the ports (42, 44 and 46) on the direction-dependent router (40) is disposed on a first side of the WDM (de)multiplexer (30).

Abstract: A device for reflecting light waves to used when building optical systems for various applications and special devices, is built on a substrate and has a planar structure. It comprises a light power coupler of the MMI-type, configured as a rectangular plate at or in the surface of the substrate. The coupler splits light incoming on an input terminal into two equal portions, each portion delivered on an output terminal. Also the coupler combines light incoming on two output terminals into combined light delivered on the input terminal. A loop is connected to the two output terminals for conducting light delivered on each one of these output terminals back into the other one of these output terminals. The loop is a planar waveguide built on the substrate, connected to an edge surface of the coupler. The loop has an outer contour comprising a multitude of linear segments and it can also have an inner contour having a polygon shape.

Abstract: The present invention relates to a tuneable add/drop demultiplexer. The add/drop multiplexer includes at least one N×N MMI-waveguide (10), where N≧3, at least N-number of Michelson waveguides (31, 32, 33 and 34), at least one Bragg grating (62, 64 and 66) per Michelson waveguide (31, 32, 33 and 34) and at least one phase control element (51, 53, 55 and 57) in at least N−1 number of Michelson waveguides (31, 32, 33 and 34). The Michelson waveguides (31, 32, 33 and 34) include said phase control elements (51, 53, 55 and 57) and said Bragg gratings (62, 64 and 66) and are coupled to at least one MMI-waveguide (10). Each Michelson waveguide (31, 32, 33 and 34) can be provided with a broadband reflection section (70). The invention also relates to a method for tuneable add/drop multiplexing, the use of a wavelength selective switch as a tuneable add/drop multiplexer and the use of a tuneable add/drop multiplexer as a wavelength selective switch.

Abstract: An apparatus for add/drop multiplexing of a wavelength channel multiplex comprises an MMI coupler (1) and MI arm section (3). The MMI coupler includes a multiplex input (7), an add channel input (9), a drop channel output (13), a multiplex output (17), and at least four input/output terminals (21, 23, 25, 27). The MI arm section includes four waveguides (29, 31, 33, 35), wherein each waveguide is optically connected to a respective one of said input/output terminals of the MMI coupler; and is at least provided with a first phase control element (37), a reflection grating (39), a second phase control element (49), and a wide frequency range reflection means (51). Further, each of the reflection gratings are provided with a heater means for tuning the respective reflection grating to the wavelength channel to be added/dropped and the wide frequency range reflection means reflect all other channels.

Abstract: The present invention relates to an apparatus and a method for wavelength selective switching of a plurality of optical wavelength channels. The apparatus comprises two MMI waveguides interconnected by at least two Mach-Zehnder waveguide structures arranged in parallel, of which each is arranged to transmit a respective portion of the intensity of said plurality of optical wavelength channels.

Abstract: The present invention relates to a device and to a method for modulating optical wavelength channels. The optical wavelength channels are switched to at least one access waveguide arranged on a first side of a first multimode waveguide (10). The wavelength channels are then transmitted through the multimode waveguide (10) and imaged on at least two connecting waveguides provided on an opposite side. The optical wavelength channels are then transmitted through the connecting waveguides.

Abstract: The invention relates to a device and a method for switching optical wavelength channels. Said optical wavelength channels are introduced into at least one access waveguide provided on a first side of a first multi-mode waveguide (10). Subsequently, the wavelength channels are transmitted through said multi-mode waveguide (10) and projected on at least two connection waveguides provided on the opposite side. Subsequently, the optical wavelength channels are transmitted through the connection waveguides. For each wavelength selective cross-connection structure (2, 4, 6, 8) the phase is changed for a reflecting wavelength of two phase control elements (C1, C2, D1, D2, E1, E2, F1, F2) arranged in a first and a second connection waveguide on a first side of said wavelength selective cross-connection structure (2, 4, 6, 8), simultaneously as at a second side of said wavelength selective cross-connection structure (2, 4, 6, 8) said reflecting wavelength phase remains relatively unchanged.