An apparatus and method for increasing efficiency of grating couplers are disclosed. The apparatus through the use of a defect or a reflective element allows coupling of light around a normal or nearly normal angle with a high efficiency. The method disclosed teaches how to increase the efficiency of a grating coupler through the use of a defect or a mirror. The apparatus and method can be of particular utility in the context of optical clocking implemented with a III-V chip flip-chip bonded on a CMOS chip.