Optical mode converter integration with InP-InGaAsP active and passive waveguides using a single regrowth process

A new method for integration of optical mode converters with InP-based photonic integrated circuits is described and demonstrated. The mode converter is integrated to a Sampled Grating DBR (SG-DBR) laser to demonstrate integration and to facilitate accurate fiber-coupling loss measurements. The entire fabrication process requires a single MOCVD regrowth, making it compatible with low-cost integration with other photonic components. The mode converter utilizes a vertically tapered geometry and yields a record 86% coupling efficiency using a lensed, uncoated, single-mode fiber. Cleaved fiber to InP-based waveguide coupling loss sensitivity is measured to be better than 1 dB with /spl plusmn/ 1.85-μm lateral fiber misalignment and /spl plusmn/1.5-μm transversal fiber misalignment.