An eye-safe atmospheric aerosol lidar featuring high transmit pulse energy
to generate strong backscatter from long ranges in a single pulse
together with an optically efficient receiver is disclosed. The
transmitter employs a gas cell and non-focused laser beam geometry to
convert short wavelength laser light to substantially safer and longer
wavelength light by stimulated Raman scattering. The longer wavelength
light is substantially safer than the shorter wavelength light thereby
allowing the safe transmission of high energy pulses. The transmitter
also features a diode injection seed and a beam expander which are
effective to reduce the divergence of the long wavelength light below the
field-of-view of the receiver. The receiver employs a telescope,
collimating lens, interference filter, focusing lens, avalanche
photodiode detector, amplifier and analog to digital converter. The
transmit beam and receiver field of view are coaxial. Initial results
demonstrate the ability of such technology to elucidate the structure of
the atmosphere with high temporal and spatial resolution.