Patent ID: 7072557

Claim:
A photonic integrated circuit (PIC) formed in a chip a plurality of such chips are formed in an InP-based wafer, each chip comprising a plurality of sequentially coupled, monolithic InP-based optical components forming the integrated circuit having an input to or an output from the circuit or both and including a Al-containing waveguide core extending through the sequentially coupled optical components to provide a common waveguide core where optical components in the circuit contain a different section of the waveguide core, the Al-containing waveguide core comprising InAlGaAs, combined layers of InGaAs/InAlAs, InGaAs/InAlGaAs or InAlAs/InAlGaAs or stacks of such layers in lieu of InGaAsP so that a birefringence variation, expressed as Δλ TE-TM , for InAlGaAs (±1 nm) is about ±3 GHz whereas the birefringence variation for InGaAsP (±10 nm) is about ±30 GHz, the deployment of the aluminum-containing waveguide core results in higher bandgap uniformity across the waveguide core-sequentially coupled optical components in the photonic integrated circuit (PIC) compared to InGaAsP-based waveguide cores that extend beyond a single optical component and providing for high uniform photoluminescent (PL) emission wavelength across the InP-based wafer from which the chips were part thereof.