Paragraph:

Light guidance in an optical fiber can be understood by considering a structure comprising of thin solid glass cylinder of refractive index \(n_{1}\) surrounded by a medium of lower refractive index \(n_{2}\). The light guidance in the structure takes place due to successive total internal reflections at the interface of the media \(n_{1}\) and \(n_{2}\) as shown in the figure. All rays with the angle of incidence \(i\) less than a particular value \(i_{m}\) are confined in the medium of refractive index \(n_{1}\). The numerical aperture (NA) of the structure is defined as \(\sin i_{m}\).





Question:

For two structures namely \(S_{1}\) with \(n_{1}=\sqrt{45} / 4\) and \(n_{2}=3 / 2\), and \(S_{2}\) with \(n_{1}=8 / 5\) and \(n_{2}=7 / 5\) and taking the refractive index of water to be \(4 / 3\) and that of air to be \(1\) , the correct option(s) is(are)