#1 I hope you have the protection needed for seeing this diode in a safe manner
#2 I hope it it not a DLED >Dead
#3 It sounds like there may be alignment issues....not in the pump chamber, but lense in front of the diode. There should be some sort of focusing optic to pump all that I/R into a somewhat collimated beam. May also need the crystals set for that diode and it's character. They seem to be like the weather on a given day. Some are very different from others........
You are the only one that can make your dreams come true....and the only one that can stop them...A.M. Dietrich