Field Intensity and Power Confinement of Four-layer Slab Waveguides with Various Refractive Index Profiles in the Guiding Region

Abstract

Relative field intensity distributions in three differenttypes of structures, i.e. Step index Slab Waveguide(SSW), Semi-parabolic index Slab Waveguide (SPSW)and Parabolic index Slab Waveguide (PSW) have beenanalytically derived and computed. It is found that thefield in the guiding region is maximum in case of thePSW structure. Analytical expressions for the relativepower confinement factors have also been obtained.The applicability of these results in the estimation ofcoupling coefficient of some of the Distributed FeedBack (DFB) lasers have also been briefly shown.