Abstract: An adaptive gas lens provides a radial flow of gas that makes phase corrections on a distorted annular wavefront passing therethrough. A flexible flange controlled by precision actuators provides for variation in gas stream width yielding variations in the optical path difference over a range of azimuthal periods.

Abstract: A process for simulating the infrared radiation in wave length and intensity and the spatially extended characteristics of the plumes of turbojet engines comprising burning fuel-rich solid gas generator compositions, comprising an organic binder, an oxidizer, and dispersed inorganic particles, of a character such that venting of the combustion products directly into the atmosphere or venting them into the inadequate plume of a separate gas generator to provide a combined plume, produces a plume having the size and radiating characteristics of the turbojet plume being simulated.