Understanding Modes in Fibre: Equations for Allowed Angles of Propagation

[Jon.G]

So I've got the equation for 'allowed angles of propagation':
SinΘ_p = pλ / 2πdn_f
With p is the mode, λ the wavelength, d the width and n the refractive index.

I'm just not sure what to do with this equation, and my lecture notes don't go into any more detail.
For example, if I knew the the max number of modes (p) and I put this into the equation, would the value I get for the angle be the maximum value for propagation in this fibre?
I know this is probably something simple I should be able to figure out, but my mind is all over the place atm and I seem to be struggling to think things through and make simple connections :P

Thanks

 

[gtoguy97]

for any help!Yes, the value you get for the angle is the maximum value for propagation in this fibre. If the refractive index and wavelength are fixed, then the angle of propagation is determined by the number of modes (p) and the width of the fibre (d). The more modes allowed, the larger the angle of propagation, and vice versa.