1
vote
2answers
56 views

Why would mode-hopping occur as the current is changed?

If some diode laser is given an input current, why should we see mode-hopping if the current is changed?
9
votes
7answers
4k views

Why is a 1mW laser dangerous?

In our Physics lab we have a 1 milliwatt (0.001W) helium neon laser. Despite the low power, we were cautioned not to even look at reflections of the beam as it could cause permanent eye damage - why ...