AIM :- Determination of N. A. & Energy Losses Related To Optical Fiber Experiment . AIM 1 :- Determination of Numerical Aperture . THEORY :- The numerical aperture of an optical system is a measure of the light collected by the optical system . It is the product of the refractive index of the incident medium and Sin of the maximum ray angle. Numerical Aperature (N. A.) = ni Sin max . (1) For ni = 1, N. A. = Sin max (2)Table a :-Sl. No.L (mm)W (mm)N. A. max (degree)

AIM 2 :- Determination of the light propagation losses in the given Optical Fiber .THEORY :- In this experiment, we study the attenuation (losses) which occurs on an optical fiber cable itself . The optical power at a distance L in an optical fiber is given by Bougers Law, PL = Pi e LWhere, Pi = the optical power launched at the input of a fiber = the attenuation co-efficient L = Fiber lengthThis is due to transmission through the length of the cable of meter L1 P01 = -10 log (PL1 P0)Similarly, the loss due to transmission due to L2 m length of the cable is P02 = -10 log (PL2 P0)Computing both equations, we can write = (P02 - P01) (L2 - L1) db/m Table b :-Sl. No.Length of the cable (mm)Power Loss (db) = (P02 - P01) (L2 - L1) db/m

AIM 3 :- Determination of the losses with air gap attenuation .THEORY :- Another marginal cause of loss in the optical fibre is the air gap in between two cables, because the total internal reflection does not occur at that air gap. So a huge amount of energy will be lost. In this experiment we will study the loss due to the air gap attenuation. Table b :-Sl. No.L air gap (mm)OpticalPower Loss (db)Attenuation (db)

So, Average Power Loss = Discussions :-