Part A from problem 1
Using the modesolver now. Changed \(n_{SiO2}=n_2=1.4456\) from problem 1. Kept m=3 just to show what modes arent guided for l=0. We know that when effective index vs wavelength falls below the index chosen for \(n_{SiO2}\) that occurs for radiative modes and aren’t guided. Figure 3 shows that \(\lambda=850 nm,1550 nm\) are guided for the \(LP_{01}\) mode.
Figure 4 shows that for \(LP_{11}\) mode, only \(\lambda=850 nm\) is guided.