As the lens is turned, the laser becomes focused, but after it has become as focused as it can become, it starts becoming unfocused again. Try turning the lens out little by little and the laser should become smaller.
Well, it's my first post after lurking here for a while, so why not start with a question?
Would there be a formula to calculate the wattage of the output of a LD by knowing the voltage and current?
Simple P=IV doesn't seem to work (or am I just doing the math wrong?).
I have a modified (ok...