laser diode variable driver

Hi i've a 150mW blue(405nm) laser diode...
I've already done a 150mA power supplier, but I want to
make another one that is variable from 10mA to 500mA...

1. Can i do it usin the LM317 and using a trimmer?
2. Does the diode work at a lower level of power (like 80mA)

thank

Yes to both, see this thread, still on the same page as yours.
It has schematics, too, just re-calculate the resistances for your purpose.

http://laserpointerforums.com/f42/help-custom-driver-47311.html