ns impulse source

i hope to get the information which company can supply controllable ns- impulse source.
i hope to implement ppm.

There are several manufacturers of impulse generators. Some examples:

www.avtechpulse.com/impulse/avh/
www.highlandtechnology.com/DSS/T200DS.html
http://www.picosecond.com/objects/35...EC-4040010.pdf
http://www.picosecond.com/objects/10...EC-4040006.pdf

Another one

www.multispectral.com

D.