Y-Junction Power Divider in InGaAsP/InP Photonic Integrated Circuits.

We demonstrate an InGaAsP/InP asymmetric waveguide Y-junction with a controlled power dividing ratio which is independent of the polarization of the input light. The Y-junction is monolithically integrated with an active optical gain section by metalorganic chemical vapor deposition (MOCVD). The integrated chip represents a fundamental building block for photonic integrated circuits. Experimental results are in agreement with a theoretical analysis of the Y-junction. Our theory also shows a low power loss (1 dB) and negligible power reflection (-63 dB) at the Y-junction which is ideal for monolithic integration with active devices.