A third InP layer 160 is then grown over areas not covered by the areas 158 of masking material, including over the areas where the MMI 144 and gain section 146 are formed and over the parallel areas 138 a, 138 b of 1.3Q InGaAsP. The third InP layer 160 is then planarized and the DBR sections 142, MMI 144, and gain section 146 are formed.