In this work we propose and fabricate a novel low cost wavelength stable single mode laser for uncooled WDM applications using hybrid semiconductor-polymer diode structures. A ridge waveguide Fabry-Perot laser with an integrated spot size convertor on the output is modified for athermal single frequency operation. The prototype device consists of an active section and an athermalized polymer grating structure. The latter is etched by focused ion beam (FIB) and filled with a negative temperature coefficient polymer material to compensate thermal wavelength drift. The active region thermal drift is thereby partially compensated by the polymer grating without requiring active wavelength or temperature control. This potentially facilitates low-cost, low-footprint, low-power-consumption packaging.