91Ó°ÊÓ

Consider a step index fiber with \(n_{1}=1.5, \Delta=0.015\) and \(a=\) 25 Um placed in air. Calculate \(n_{2}\) and the maximum acceptance angle \(\left(i_{m}\right)\). If the fiber tip is immersed in water \((n=1.33)\), calculate the maximum acceptance angle (t) [Ans: \(1.477 ; 0.26 ; 15^{\circ} .11 .3^{\circ}\)

A step index optical fiber with \(n_{1}=1.46, n_{2}=1.44\), and core radius \(a=50 \mu \mathrm{m}\) is placed in air. Calculate the maximum acceptance angle. If the fiber is now immersed in water \((n=1.33)\), calculate the maximum acceptance angle [Ans: \(13.9^{\circ}: 10.4^{\circ}\)