Realisation of Multi-Wavelength Phased Array Laser by Hybrid Coupling of Active and Passive Waveguide Chips

Abstract

For many novel integrated WDM-devices such as multi-wavelength lasers (MWL), the integration of passive waveguides and active devices is required. Several techniques such as butt coupling, shadow mask growth or selective area growth have been proposed for realising monolithic integrated photonic integrated circuits (PIC). Whatever integration scheme is used, it requires a lot more processing steps compared to the realisation of a standard laser or a passive waveguide device. As a consequence the fabrication of PICs is much more time consuming and expensive at the development stage, which leads to long iteration cycles to realise optimised devices. Moreover, since the passive devices are often rather big, it is generally not possible to put many variations of the device on one wafer. We propose and demonstrate a hybrid solution that allows to test and evaluate new devices, using a standardised array of amplifier stripes and a passive waveguide chip coupled together on an optical bench. This approach allows for rapid testing and optimisation of new passive waveguide designs as part of an active device. To avoid reflections at the passive-active interface amplifiers and passive wave guides are angled at the facet and a standard AR-coating is applied.