Discussion is never a problem ....;-}
The issue is that the signal is "too loud" and is distorted (or, more correctly, is so loud it overloads the receiver).
The operational envelope for nearly every receiver of any kind includes a bottom number (too weak to hear) and a top number (too loud to understand).
As an example, think about an system where you have a hearing aid that would let you hear someone speaking in a normal voice from 100 feet away ... then having someone scream the same words into the hearing aid from 6 inches away ... the sound would be distorted and you would have difficulty understanding them ... after a while, you'd begein to go deaf and eventually, it would sound normal (until you became completely deaf).
So, what you need to do is look at the transmitter power, and the envelope/range of acceptable power the receiver can hear.
Normally that difference is the optical budget ... given the loss numbers of the media between the two, you can determine if you have enough power to make the trip.
In a Lab environment, you still have to hit the receiver's budget number, but from the other end (the "too high" side).
If you know the transmitter puts out X, and the receiver can accept from Y to (X-50), then you need to add enough attenuation to get X down to (X-50)or lower (but still more than Y).
When you have a transmitter powerful enough to drive tens of kilometers, putting one two meters away from the receiver will pretty much guarantee a burnout (unless you install optical attenuation).
Good Luck
Scott
