US 12,736,752 B2 · Contradirectional-filter architecture having low back-reflection

Abstract

The teachings of the present disclosure enable wavelength-agile WDM systems comprising wavelength drop ports based on contra-DC wavelength filters, where back-reflections at each drop port are mitigated by virtue of the system architecture. The contra-DC filters are arranged in a series along a common bus waveguide such that the operating wavelengths of the filters change in monotonic fashion through the series. As a result, back-reflections arising at each filter is suppressed by the contra-DC filter that precedes it in the series. In some embodiments, each contra-DC filter is configured such that its filter bandwidth is large enough to accommodate both its drop signal and back-reflections arising from the grating element of the preceding contra-DC filter in the series. In some embodiments, conventional back-reflection approaches are used in concert with the system-architecture approach of the present disclosure.

Claims19

Dependent claims

A wavelength division multiplexed (WDM) system comprising:

a bus waveguide for receiving a WDM signal that includes a plurality of wavelength signals, wherein the bus waveguide includes a plurality of bus-waveguide portions;
and
a plurality of contra-directional coupler (contra-DC) filters that is optically coupled with the bus waveguide, wherein each contra-DC filter of the plurality thereof is characterized by a different filter bandwidth and different drop signal that includes a drop wavelength, and wherein the plurality of contra-DC filters is arranged in a series along the bus waveguide such that the plurality of filter bandwidths are non-overlapping and the plurality of drop wavelengths changes monotonically along the series;
wherein each contra-DC filter includes a grating element that is optically coupled with a different bus-waveguide portion of the plurality thereof, the grating element comprising a periodic arrangement of teeth and a grating waveguide that extends through the entire length of the grating element, the grating waveguide including a drop port.

1 more element

A method for dropping at least one wavelength signal from a wavelength divisional multiplexed (WDM) signal that includes a first plurality of wavelength signals, the method comprising:

providing the WDM signal on a bus waveguide that is operatively coupled with a plurality of contra-directional coupler (contra-DC) filters, wherein each contra-DC filter of the plurality thereof is characterized by a different filter bandwidth and different drop signal that includes a drop wavelength, and wherein the plurality of contra-DC filters is arranged in a series along the bus waveguide such that the plurality of filter bandwidths are non-overlapping and the plurality of drop wavelengths changes monotonically along the series;
dropping a first drop signal to a first drop port of a first contra-DC filter of the plurality thereof;
and
dropping a second drop signal at a second drop port of a second contra-DC filter of the plurality thereof.

1 more element

Dependencies are inferred from the claim text.

Contradirectional-filter architecture having low back-reflection

Life of this patent

Contradirectional-filter architecture having low back-reflection

Life of this patent

Abstract

Claims19