Experimental and theoretical investigation of Mode Size Effects on Tilted Facet Reflectivity

Facet reflectivity from tilted devices has been investigated as a function of optical mode size. A theoretical approach is developed and completed by numerical simulation in order to calculate the effective facet reflectivity depending on optical mode size. The proposed approach is based on the plane wave expansion. Compared to other methods, the proposed one reveals clearly the physical insights and requires low computational effort and exhibits high reliability. We found that for a mode size of 4.5 µm and 7° of mirror tilt, a reflectivity of 1.34x10-2 % is obtained; for a mode size of 1.7 µm, a 7° tilt introduces a facet reflectivity of 6.25 %.