Gas-lens type deflection structure for light beams

The efficient transmission along a curved path represents a problem which has to be solved before the application for long-distance communication can be further considered. Small changes of the direction of propagation can be achieved directly by curved gas lenses. It is the purpose of this letter to describe a method by which a light beam can be deflected with low losses. The method is based on the effects of thermal gradients in gases. The study carried out in our laboratory actually has a two-fold purpose, namely, a) the design of a test section in whch the effects of thermal gradients on light beams can be investigated under well defined experimental conditions; and b) to show the possibility of using such a structure for the beam deflection separated from the focusing gas lenses.