Tunable Wavelength Filter
AssigneeOctrolix BV
InventorsEdwin Jan Klein, Rene Gerrit Heideman
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Abstract
A wavelength filter based on a symmetric PLC circuit comprising an MZ filter-based demultiplexer, a waveguide resonator, and an MZ filter-based multiplexer is presented. The wavelength filter is tuned using pulse width modulated drive signals that enable fine wavelength control resolution. Embodiments in accordance with the present invention attain narrow spectral filtering capability over a wide wavelength tuning range. Further, embodiments in accordance with the present invention mitigate chromatic dispersion.
Claims27
A wavelength filter, the wavelength filter comprising:
- a wavelength demultiplexer comprising first vernier filter comprising a first lattice filter that is a Mach-Zehnder filter and a second lattice filter that is a Mach-Zehnder filter;
- a waveguide resonator;
- and
- a wavelength multiplexer comprising a second vernier filter comprising a third lattice filter that is a Mach-Zehnder filter and a fourth lattice filter that is a Mach-Zehnder filter;
- wherein the wavelength demultiplexer, the waveguide resonator, and the wavelength multiplexer collectively define a planar lightwave circuit that is substantially symmetric about a line of symmetry through the waveguide resonator, and wherein the planar lightwave circuit is wavelength tunable over a wavelength range.
The wavelength filter 4 wherein the first vernier filter is characterized by a filter response having a plurality of nulls, and wherein the waveguide resonator is characterized by a fourth free spectral range that is substantially equal to the third free spectral range.
A wavelength filter, the waveguide filter comprising:
- a first vernier filter comprising a first lattice filter that is a surface-waveguide-based Mach-Zehnder filter and a second lattice filter that is a surface-waveguide-based Mach-Zehnder filter, wherein the first lattice filter is wavelength-tunable;
- a second vernier filter comprising a third lattice filter that is a surface-waveguide-based Mach-Zehnder filter and a fourth lattice filter that is a surface-waveguide-based Mach-Zehnder filter, wherein the third lattice filter is wavelength-tunable;
- and
- a waveguide resonator, wherein the first vernier filter and second vernier filter are substantially symmetric about a line of symmetry through the waveguide resonator;
- wherein the first vernier filter, second vernier filter, and waveguide resonator are optically coupled.
A method comprising:
- receiving a first light signal at a first vernier filter comprising a first lattice filter that comprises a wavelength-tunable Mach-Zehnder filter, the first light signal being characterized by a first wavelength range;
- providing a second light signal from the first vernier filter, the second light signal being a portion of the first light signal characterized by a second wavelength range that is narrower than the first wavelength range;
- receiving the second light signal at a waveguide resonator;
- and
- providing a third light signal from the waveguide resonator, the third light signal being a portion of the second light signal characterized by a third wavelength range that is narrower than the second wavelength range.
Dependencies are inferred from the claim text.