Series of liquids are proposed for use as optical components, and as l
aser cavities and waveguides. Pulsed pumping of such cavities at lambd
a = 532 nm resulted in lasing in the range 630-640 nm, which was inves
tigated. Special features of liquid optical components used as sensors
and employed in investigations of a variety of nonlinear processes we
re considered. The use of volatile fluoro-organic compounds, which red
uce the surface tension when in contact with liquids, induced a self-o
rganising capillary instability of optical and laser components with c
onstant wave-like or chaotic motion of their surface layers.