An optical fibre transmission system consists of a circular LED source, a 2-metre length of optical fibre and a circular PIN diode detector. Both the source and detector are positioned 100 µm from the ends of the fibre. Detailed data for the source, a glass fibre, a polymer fibre and the detector are given below. Use this data to perform the following calculations.

(a) The total power Ps emitted by the source in all directions (use eqn [15.23b]).

(b) The numerical aperture and maximum angle of acceptance of the glass fibre.

(c) The numerical aperture and maximum angle of acceptance of the polymer fibre.

(d) The source and detector are linked by the glass fibre; calculate the power input to the fibre, the fibre transmission factor, and power output from the fibre.

(e) The source and detector are now linked by the polymer fibre; calculate the power input to the fibre, the fibre transmission factor, and power output from the fibre.

(f) For both the glass system of (d) and the polymer system of (e), calculate the power incident on the detector and the detector output current.