(b) A step index fiber has a numerical aperture, NA 0.2588, core refractive index = 1.5 , cladding refractive index = 1.47 and a diameter 125µm. A light source is %3D coupled to this fiber which emits 75% of its light into a 60 degree full-cone angle, 50% into a 30 degree cone and 25% into a 15 degree cone. Calculate the following when this.source and fiber are connected: (i) Acceptance angle (ii} Coupling efficiency (iii) The critical angle at the core cladding interface [9]

(b) A step index fiber has a numerical aperture, NA 0.2588, core refractive index = 1.5 , cladding refractive index = 1.47 and a diameter 125µm. A light source is %3D coupled to this fiber which emits 75% of its light into a 60 degree full-cone angle, 50% into a 30 degree cone and 25% into a 15 degree cone. Calculate the following when this.source and fiber are connected: (i) Acceptance angle (ii} Coupling efficiency (iii) The critical angle at the core cladding interface [9]