Tuneable optical filter

A wavelength selective filter for tuneable filtration of one or more wavelength channels from a stream of Q-number of wavelength channels, characterised in that the filter includes one or more devices for filtering out a specific wavelength channel, wherein each device includes an input and an output, a part through which solely said specific wavelength channel passes through and which includes at least one on-off switch which when in an off-mode prevents said specific wavelength channel from passing through said device for filtering out a specific wavelength channel, wherein in the event of more than one device for filtering out a specific wavelength channel, said devices are interconnected by a connecting waveguide between the output of one device and the input of another device, so as to enable several channels to be filtered out independently of each other, wherein

• the device for filtering out a specific wavelength channel includes first and second Multi Mode Interference Bragg-grating (MMIBg) circuits, wherein an output on a first side of an MMI-waveguide (210 and 240) in the first MMIBg (10 and 14) is connected to an input on a first side of an MMI-waveguide (220 and 260) in the second MMIBg (12 and 16) via a connecting waveguide (62 and 64) which includes said on-off switch (20 and 22), and wherein a second side of said MMI-waveguide (210 and 240) in the first MMIBg (10 and 14) is connected to a second side of said MMI-waveguide (220 and 260) in the second MMIBg (12 and 16) via a connecting waveguide (60 and 61).

A wavelength selective filter for tuneable filtration of one or more wavelength channels from a stream of Q-number of wavelength channels, characterised in that the filter includes one or more devices for filtering out a specific wavelength channel, wherein each device includes an input and an output, a part through which solely said specific wavelength channel passes through and which includes at least one on-off switch which when in an off-mode prevents said specific wavelength channel from passing through said device for filtering out a specific wavelength channel, wherein in the event of more than one device for filtering out a specific wavelength channel, said devices are interconnected by a connecting waveguide between the output of one device and the input of another device, so as to enable several channels to be filtered out independently of each other, wherein

• the device for filtering out a specific wavelength channel includes an MMI-waveguide (215, 225, 245 and 265), a total reflection section (70, 72, 74 and 76), a first Michelson waveguide (112, 122, 142 and 162) which includes a phase-shifted Bragg grating which will only allow one wavelength channel to pass through and a first on-off switch (20A, 22A, 24A and 26A), a second Michelson waveguide (114, 124, 144, 164) which includes a phase-shifted Bragg grating that will only allow one wavelength channel to pass through and a second on-off switch (20B, 22B, 24B and 26B), wherein the MMI-waveguide and the total reflection section (70, 72, 74, 76) are interconnected via said first Michelson waveguide (112, 122, 142 and 162) and said second Michelson waveguide (114, 124, 144 and 164) in which said phase-shifted Bragg gratings are arranged closer to said MMI-waveguide than to said on-off switches (20A, 20B, 22A, 22B, 24A, 24B, 26A and 26B).

A wavelength selective filter for tuneable filtration of one or more wavelength channels from a stream of Q-number of wavelength channels, characterised in that the filter includes one or more devices for filtering out a specific wavelength channel, wherein each device includes an input and an output, a part through which solely said specific wavelength channel passes through and which includes at least one on-off switch which when in an off-mode prevents said specific wavelength channel from passing through said device for filtering out a specific wavelength channel, wherein in the event of more than one device for filtering out a specific wavelength channel, said devices are interconnected by a connecting waveguide between the output of one device and the input of another device, so as to enable several channels to be filtered out independently of each other, wherein

• the device for filtering out a specific wavelength channel includes an MMI-waveguide (215, 225, 245 and 265), a first Michelson waveguide (112, 122, 142 and 162) which includes a phase-shifted Bragg grating that will only allow one wavelength channel λi to pass through, a first on-off switch (20A, 22A, 24A and 26A) and a Bragg grating which solely reflects said wavelength channel λi, a second Michelson waveguide (114, 124, 144, 164) which includes a phase-shifted Bragg grating that will only allow one wavelength channel λi to pass through, a second on-off switch (20B, 22B, 24B an 26B), and a Bragg grating which solely reflects said wavelength channel λi, wherein said Michelson waveguides are connected to a second side of the MMI-waveguide and wherein the on-off switches are disposed between the phase-shifted Bragg gratings that solely allow one wavelength channel λi to pass through and the Bragg gratings which solely reflect said wavelength channel λi, and wherein the phase-shifted Bragg gratings are disposed nearest the MMI-waveguide (215, 225, 245 and 265).

A wavelength selective filter for tuneable filtration of one or more wavelength channels from a stream of Q-number of wavelength channels, characterised in that the filter includes one or more devices for filtering out a specific wavelength channel, wherein each device includes an input and an output, a part through which solely said specific wavelength channel passes through and which includes at least one on-off switch which when in an off-mode prevents said specific wavelength channel from passing through said device for filtering out a specific wavelength channel, wherein in the event of more than one device for filtering out a specific wavelength channel, said devices are interconnected by a connecting waveguide between the output of one device and the input of another device, so as to enable several channels to be filtered out independently of each other, wherein

• the device for filtering out a specific wavelength channel includes an MMI-waveguide (215, 225, 245 and 265), a first Michelson waveguide (112, 122, 142 and 162) which includes a Bragg grating that allows only wavelength channels whose wavelengths are longer than λi−1 to pass through, a Bragg grating that allows only wavelength channels whose wavelengths are shorter than λi+1 to pass through, a first on-off switch (20A, 22A, 24A and 26A), and a Bragg grating which reflects solely said wavelength channel λi, a second Michelson waveguide (114, 124, 144, and 164) which includes a Bragg grating that will only allow wavelength channels whose wavelength is longer than λi−1 to pass through, a Bragg grating that will only allow wavelength channels whose wavelengths are shorter than λi+1 to pass through, a second on-off switch (20B, 22B, 24B and 26B) and a Bragg grating that reflects solely said wavelength channel λi, wherein the Michelson waveguides are connected to a second side of the MMI-waveguide and wherein the on-off switches are disposed between the Bragg gratings that solely allow wavelength channels whose wavelengths are shorter than λi+1 to pass through and the Bragg gratings that reflect solely said wavelength channel λi.

A wavelength selective filter for tuneable filtration of one or more wavelength channels from a stream of Q-number of wavelength channels, wherein the filter includes one or more devices for filtering out a specific wavelength channel, wherein each device comprises:

• an input;
• an output;
• and
• a part through which solely said specific wavelength channel passes through and which includes an on-off switch which when in an off-mode prevents said specific wavelength channel from passing through said device for filtering out a specific wavelength channel,
• wherein the device for filtering out a specific wavelength channel includes first and second Bragg-grating assisted Mach-Zehnder Interferometers (MZI), wherein an output on a first MMI-waveguide in the first Bragg-grating assisted Mach-Zehnder Interferometer is connected to an input on a first MMI-waveguide in the second Bragg-grating assisted Mach-Zehnder Interferometer via a first connecting waveguide in which said on-off switch is included, and
• wherein a second MMI-waveguide in the first Bragg-grating assisted Mach-Zehnder Interferometer is connected to a second MMI-waveguide in the second Bragg-grating assisted Mach-Zehnder Interferometer via a second connecting waveguide.

A wavelength selective filter for tuneable filtration of one or more wavelength channels from a stream of Q-number of wavelength channels, wherein the filter includes one or more devices for filtering out a specific wavelength channel, wherein each device comprises:

• an input;
• an output;
• and
• a part through which solely said specific wavelength channel passes through and which includes an on-off switch which when in an off-mode prevents said specific wavelength channel from passing through said device for filtering out a specific wavelength channel,
• wherein the device for filtering out a specific wavelength channel includes first and second Multi Mode Interference Bragg-gratings (MMIBg), wherein an output on a first side of an MMI-waveguide in the first MMIBg is connected to an input on a first side of an MMI-waveguide in the second MMIBg via a first connecting waveguide which includes said on-off switch, and
• wherein a second side of the MMI-waveguide in the first MMIBg is connected to a second side of the MMI-waveguide in the second MMIBg via a second connecting waveguide.

A wavelength selective filter for tuneable filtration of one or more wavelength channels from a stream of Q-number of wavelength channels, wherein the filter includes one or more devices for filtering out a specific wavelength channel, wherein each device comprises:

• an input;
• an output;
• and
• a part through which solely said specific wavelength channel passes through and which includes an on-off switch which when in an off-mode prevents said specific wavelength channel from passing through said device for filtering out a specific wavelength channel,
• wherein the device for filtering out a specific wavelength channel includes a first MMI-waveguide and a second MMI-waveguide which are interconnected via a first Mach-Zehnder waveguide and a second Mach-Zehnder waveguide which each include a respective Bragg grating,
• wherein an output and an input on a side of the second MMI-waveguide are interconnected via said on-off switch.

A wavelength selective filter for tuneable filtration of one or more wavelength channels from a stream of Q-number of wavelength channels, wherein the filter includes one or more devices for filtering out a specific wavelength channel, wherein each device comprises:

• an input;
• an output;
• and
• a part through which solely said specific wavelength channel passes through and which includes an on-off switch which when in an off-mode prevents said specific wavelength channel from passing through said device for filtering out a specific wavelength channel,
• wherein the device for filtering out a specific wavelength channel comprises
• an MMI-waveguide,
• a total reflection section,
• a first Michelson waveguide which includes a first phase-shifted Bragg grating which will only allow one wavelength channel to pass through and a first on-off switch, and
• a second Michelson waveguide which includes a second phase-shifted Bragg grating that will only allow one wavelength channel to pass through and a second on-off switch,
• wherein the MMI-waveguide and the total reflection section are interconnected via the first Michelson waveguide and the second Michelson waveguide, and
• wherein the first and second phase-shifted Bragg gratings in the first and second Michelson waveguides are arranged closer to the MMI-waveguide than to the on-off switches.

A wavelength selective filter for tuneable filtration of one or more wavelength channels from a stream of Q-number of wavelength channels, wherein the filter includes one or more devices for filtering out a specific wavelength channel, wherein each device comprises:

• an input;
• an output;
• and
• a part through which solely said specific wavelength channel passes through and which includes an on-off switch which when in an off-mode prevents said specific wavelength channel from passing through said device for filtering out a specific wavelength channel,
• wherein the device for filtering out a specific wavelength channel comprises
• an MMI-waveguide,
• a first Michelson waveguide which includes a first phase-shifted Bragg grating that will only allow one wavelength channel λi to pass through, a first on-off switch, and a first Bragg grating which solely reflects said wavelength channel λi, and
• a second Michelson waveguide which includes a second phase-shifted Bragg grating that will only allow one wavelength channel λi to pass through, a second on-off switch, and a second Bragg grating which solely reflects said wavelength channel λi,
• wherein said Michelson waveguides are connected to a side of the MMI-waveguide,
• wherein the on-off switches are disposed between the phase-shifted Bragg gratings that solely allow one wavelength channel λi to pass through and the Bragg gratings which solely reflect said wavelength channel λi, and
• wherein the phase-shifted Bragg gratings are disposed nearest the MMI-waveguide.

A wavelength selective filter for tuneable filtration of one or more wavelength channels from a stream of Q-number of wavelength channels, wherein the filter includes one or more devices for filtering out a specific wavelength channel, wherein each device comprises:

• an input;
• an output;
• and
• a part through which solely said specific wavelength channel passes through and which includes an on-off switch which when in an off-mode prevents said specific wavelength channel from passing through said device for filtering out a specific wavelength channel,
• wherein the device for filtering out a specific wavelength channel comprises
• an MMI-waveguide,
• a first Michelson waveguide which includes a first Bragg grating that allows only wavelength channels whose wavelengths are longer than λi−1 to pass through, a first Bragg grating that allows only wavelength channels whose wavelengths are shorter than λi+1 to pass through, a first on-off switch, and a first Bragg grating which reflects solely said wavelength channel λi,
• a second Michelson waveguide which includes a second Bragg grating that will only allow wavelength channels whose wavelength is longer than λi−1 to pass through, a second Bragg grating that will only allow wavelength channels whose wavelengths are shorter than λi+1 to pass through, a second on-off switch and a second Bragg grating that reflects solely said wavelength channel λi,
• wherein the Michelson waveguides are connected to a side of the MMI-waveguide,
• wherein the on-off switches are disposed between the Bragg gratings that solely allow wavelength channels whose wavelengths are shorter than λi+1 to pass through and the Bragg gratings that reflect solely said wavelength channel λi.