Optical-mode transformer: a III-V circuit integration enabler

Further development in optical fiber communications at 1.3 and 1.5 μm not only requires the improvement of components, but also hinges on the capability to fabricate optoelectronic circuits on a mass scale. Hybrid and monolithic integration of these components are expected to yield the means to mass produce optoelectronic circuits with the required characteristics. Effort is currently deployed to find simplified ways to optically interconnect such diverse components as lasers, modulators, waveguides, switches, filters and detectors, either by fiber pigtailing, hybridization on a Si-motherboard; or by monolithic integration on a single chip of InP. In this paper, emphasis is placed on the efficiency of optical-mode transformer (OMT) as a versatile solution to overcome the main technological obstacles of optical interconnection between InP-based components. A few examples will highlight the enabling qualities for fiber pigtailing and photonic integration