This paper presents the simulation results of top nano-grating on solar cell using rigorous coupled wave analysis (RCWA) method. However, compared to other simulation results, we calculated weighted total transmission of solar cell according to Sun spectrum and Silicon photo detector responsivity. Our optimization shows that the top grating with period 200nm, width 40nm, and height 150nm is the optimization structure. This case has 0.45544 total weighted transmission powers and is about 70.9% improvement compared to the non-grating case.

This paper focuses on the optical mode analysis of laser diodes to improve light emission. Under the mode analysis, we compare the optical confinement factor (OCF) percentage of the emitting light from the LDs. There are two structures which we analyze: a basic GaN waveguide structure and an InGaN waveguide structure. The second structure has additional InGaN waveguides and is analyzed under two additional design variations: the concentration of Indium and the thickness of the top waveguide layer. The results of this study indicate introducing InGaN waveguide layers correlates with lower order modes (zero and first order) and increase the OCF values. The top InGaN waveguide layer, which has a higher concentration of Indium, appears to increase the OCF. However, the increased thickness of the InGaN layer causes the lower modes’ OFC to decrease. Over all, in the best case, InGaN LD has an OCF of 1.8896%, which is about a 312% improvement compared to that of GaN LD ( OCF=0.4535%).