I am a laser diode packaging process, although not necessarily correct, but have reference significance:
1. The luminescent area is the key part, and in principle, it is forbidden to contact with anything. If the luminous area is polluted or damaged, it will directly affect his power. The situation is not very serious and it may not be bad.
2. Poor heat dissipation
3. Static electricity (basically 100% burnt out)
4. Instantaneous voltage or current is too high (mainly reflected in the moment when it was first lit)
For power, adjust the current too large, reduce the laser diode service life.
Or it may be caused by damage to the head or water that causes the instantaneous voltage to be too large and the diode is burned.