If that was a pic with the lens, then that beam profile would be more f*cked than those blonde hookers you find on street corners. Terrible analogy, yes, I know.
Anyway.
This phenomena is observable in quite a handful of diodes, including red and 445nm diodes running below threshold (so laser emission doesn't drown out these fluorescence lines).
It's not caused by contaminants in the can, nor is it a 'problem'. Rather, it is caused by contaminants in the diode's die itself, left during manufacturing. Although the manufacturing process is pretty damn good for what it is, it isn't perfect, and impurities do make their way into the dies. These emissions don't affect the operation of the laser diode itself, and are completely swamped by the resonant wavelength in normal operation.
One of the veterans here who works with laser diodes, pullbangdead, may be able to shed some more light on this (pun intended).
There have been multiple threads about this, and references in the FAQ too, but seeing as the forum search function is downright horrible, it's not worth the time trying to find those many-year old threads.
