Low-ripple optical device

1. A low-ripple optical device comprising:

an optical demultiplexing structure;

an optical multiplexing structure, optically cascaded to the optical demultiplexing structure by one or more connecting optical paths;

CHARACTERIZED IN THAT:

one of the structures exhibits n passband maxima in each connecting optical path while the other structure exhibits n+1 passband maxima in each connecting optical path wherein the overall optical device exhibits a low net passband ripple.

2. The optical device of claim 1 further CHARACTERIZED IN THAT one of the structures includes an auxiliary interferometer optically coupled to an input of that one structure while the other structure includes an auxiliary interferometer optically coupled to an output of that other structure.

3. The optical device of claim 2 further CHARACTERIZED IN THAT one of the auxiliary interferometers has n optical paths while the other auxiliary interferometers has n+1 optical paths.

4. The optical device of claim 3 further CHARACTERIZED IN THAT one of the auxiliary interferometers exhibit a Mach-Zehnder geometry.

5. A method of generating a low-ripple optical signal comprising the steps of:

applying an optical signal to the input of an optical device comprising an optical demultiplexer structure and an optical multiplexer structure cascaded together by one or more connecting optical paths; and

receiving a low-ripple optical signal output from the device;

wherein one of the optical structures exhibits n passband maxima in each connecting optical path and the other one of the optical structures exhibits n+1 passband maxima in each connecting optical path.

6. The optical device of claim 1 wherein said optical demultiplexing structure comprises:

a first frequency routing device having at least one input port and P output ports;

a second frequency routing device having at least P input ports and at least one output port, each output port of the second frequency routing device being connected to the one or more connecting optical paths; and

P optical paths coupling the output ports of the first frequency routing device to the input ports of the second frequency routing device;

and said optical multiplexing structure comprises:

a third frequency routing device having at least one input port and P output ports, wherein each input port of the third frequency routing device is connected to the one or more connecting optical paths;

a fourth frequency routing device having at least P input ports and at least one output port; and

P optical paths coupling the output ports of the third frequency routing device to the input ports of the fourth frequency routing device.

7. The optical device of claim 5 wherein said optical demultiplexing structure comprises:

a first frequency routing device having at least one input port and P output ports;

a second frequency routing device having at least P input ports and at least one output port, each output port of the second frequency routing device being connected to the one or more connecting optical paths; and

P optical paths coupling the output ports of the first frequency routing device to the input ports of the second frequency routing device;

and said optical multiplexing structure comprises:

a third frequency routing device having at least one input port and P output ports, wherein each input port of the third frequency routing device is connected to the one or more connecting optical paths;

a fourth frequency routing device having at least P input ports and at least one output port; and

P optical paths coupling the output ports of the third frequency routing device to the input ports of the fourth frequency routing device.