Different designs of the optical cavities used to focus the pumping
light source to obtain laser action in Ruby rods and Neodymium doped glass were
investigated. Giant optical pulses were produced by Q-switching by
active and passive means.
Laser light at other frequncies was obtained using the stimulated Raman process. By
passing the laser beam and the other frequencies produced by the Raman process through
crystals with suitable non-linear
properties, a wide range of frequencies was produced.