Laser Safety

This project is based on SPL PL90_3 laser diode. Its maximum pulsed optical power is 75W. Its wavelength is 905 nm.
BE CAREFUL - LASER IS EMITTING INVISIBLE LASER RADIATION, IT COULD BE DANGEROUS FOR YOUR EYES!

The value of maximum pulsed power in my LIDAR is smaller because of smaller laser current (less that 20A in peak).
Approximate value of the pulse length is 20-30ns (at 16V).
The capacity of C17 is 20 nF which gives theoretical energy that capacitor could store - 2,5 uJ. Lasers energy conversion efficiency is near 30%, which means that maximum optical energy of the single pulse is 0.75 uJ.

There is no risk of continuous laser light - all energy for the laser is stored in C17 capacitor, current from power source to the laser is limited by R18 at 0.1A level. So laser would not emit light if some problem happens with MOSFET.

I had measured average power of the laser diode in 1 kHz mode (with "not_scanning_fw"), laser collimating lens was installed. It was near 0.4 mW. That means that real pulse energy is ~0.4 uJ. This mismatch with theory can be produced by additional losses in electronics and in lens.
This 0.4 mW of invisible laser radiation can be dangerous, so
DO NOT WORK WITHOUT PROTECTION GLASSES IN NOT SCANNING MODE! PROTECTION GLASSES MUST BLOCK IR LIGHT. AVOID DIRECTING LASER TO REFLECTING SURFACES!

Scanning mode

Measurement rate can reach 11 kHz at 15 rotations/s (for 720 points per rotation). That means that average power could be 4.4 mW. That could be dangerous in "not scanning" mode, but in scanning mode laser beam is moving continuously, which decreases average power in single direction. Average optical power for every 0.5 deg sector is ~6 uW.

DO NOT LOOK TO THE LASER THROUGH MAGNIFYING OPTICS IN ANY CASE!