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.