[Laser] pulsed laser comms

[glennt at charter.net]

Hi all.

I'm not sure I've read  on this thread anything that describes how the pulsed laser comms works and why we should expect better SNR with a pulsed laser than with a CW laser and FFT processing.

The difference is that instead of a CW laser with a few milliwats of power, the pulsed laser will have peak amplitudes of tens to hundreds of watts - a 40dB to 50dB improvement. The trick is to look at the received signal only when it might be there and ignore the noise the rest of the time. The available bandwidth of the modulation will be something like half the laser PRF. The SNR of the signal will be improved because the pulsed laser is 40dB to 50dB  more than a typical CW laser.

73 de Glenn wb6w