The question might be very basic, but I could not conclude it after thinking and searching about a couple of hours.
If a light in fiber optics is launched in an SMF, therefore, it is connected to an MMF with a connector, then how to calculate the transmitted light in dBm or mW or in any other unit provided that the radius of both fibers are given?
If I transmit the light just from opposite direction, then what would be the calculation of light transmission?
Note that, I have experimented both SMF to MMF and MMF to SMF light transmission and found that SMF to MMF gives better light transmission than MMF to SMF. But I want to find that why it is? what is the actual calculation behind it?
Thanks in advance.