because lasers are very inefficient, Mr. Crapo described how to determine battery capacity/power and infer efficiency, typically 2–3%. read more
A green laser, for instance, uses an IR laser pump (at 5–10 %), which then, the IR is converted into green (by secondary harmonic generator, (4) 1064 nm NIR photons in, (2) 532 nm out IF it is 100% efficient, which it is not even 50%, so >8 in 2 out) so, you are getting only a few percent, of a few percent, of the power in, to laser light out. read more
Think about what your phone is doing all day. If it’s constantly lighting up, vibrating, or playing notification sounds, you’ve probably figured out why the battery dies so quickly. A constant stream of notifications is hard on your phone’s battery life. read more