External cavity laser array with monolithically integrated glass waveguide and Rowland circle grating for WDM applications

Wavelength division multiplexing (WDM) is rapidly becoming a mainstream technology for high capacity optical communications. One of the critical components needed in WDM systems is a multi-wavelength laser array. The external cavity laser array configuration, which exhibits accurate channel spacing control, is particularly appealing for many WDM systems. Up to now all integrated external laser array processes require one or more steps or semiconductor regrowth and/or alloy disordering to produce the passive elements. These greatly limit the materials and devices which can be used. In this paper we present an integrated WDM laser array based on an external glass cavity Rowland circle spectrometer which does not require a regrowth process. The laser array process is fully compatible with the conventional ridge laser process and, thus, can be implemented in all materials systems.