US 11,309,965 B2 · Efficiently combining multiple taps of an optical filter

Abstract

An optical filter comprises an array of waveguides fabricated on an optical integrated circuit (PIC). The array comprises individual waveguides, each of which receive light inputs, e.g., individual taps of a multi-tap optical filter used in an interference cancellation circuit. Typically, the output(s) of the individual waveguides are located at an exit (edge) of the PIC. At least one second waveguide in the array is patterned on the PIC in a converged configuration such that the light transiting these waveguides co-propagates and interacts across given portions of the respective waveguides before exiting the waveguide array along a common facet, thereby generating or inhibiting one of intermodulation products, and harmonics. This structural configuration enables the generation of various modes of transmission at the PIC exit, enabling more efficient transfer of the energy, e.g., to an associated photodetector (PD) that provides conversion of the energy to the RF domain.

Claims18

Dependent claims

A waveguide structure for optically coupling a first tap output of an optical filter assembly to a photodetector and a second tap output of the optical filter assembly to the photodetector, the waveguide structure comprising:

a substrate defined by a length;
a first optical waveguide disposed at least partially on the substrate and comprising:
a first inlet optically coupled to the first tap output;
a first linear region extending at least partially across the length of the substrate;
and
a first transition region optically coupling the first linear region to a common output optically coupled to the photodetector;
and
a second optical waveguide disposed at least partially on the substrate and comprising:
a second inlet optically coupled to the second tap output;
a second linear region extending at least partially across the length of the substrate parallel to the first linear region of the first optical waveguide;
and
a second transition region converging toward the first transition region, the second optical waveguide optically coupling the second linear region to the common output;
wherein:
a distance separating the first optical waveguide from the second optical waveguide at a location along the length of the substrate facilitates a supermode of photons traversing the first optical waveguide and a supermode of photons traversing the second optical waveguide.

11 more elements

Dependencies are inferred from the claim text.

Efficiently combining multiple taps of an optical filter

Life of this patent

Efficiently combining multiple taps of an optical filter

Life of this patent

Abstract

Claims18