Aerodynamic windows utilize gas flows to provide pressure and gas species isolation interfaces which are transparent to laser radiation. The feasibility of using a shock tube generated pulsed flow field as a single-shot window for short, high-energy laser pulses was investigated. A primary application of such a window would be for the single pulse gas laser driven inertial confinement fusion test facility currently planned by DoE. Experiments were performed to define operating conditions which cause a minimal degradation in the quality of a laser beam transmitted through the window. In the experiments a scribed dia-phragm shock tube with glass endwalls was used to simulate the window, and a ruby laser pulse was transmitted along the tube axis after the diaphragm burst. The optical quality of the nearly one-dimensional pressure wave field and the turbulent contact interface was recorded holographically at different delay times for a variety of pressures and gas compositions in the driver and driven sections of the shock tube. Interferograms were interpreted using digital techniques to determine beam quality degredations. A beam quality of 1.33, at the ruby laser wavelength, was routinely obtained after transmission through the window flow-field. This performance is more than adequate to meet the laser fusion requirements.

Date Published: 30 December 1981
PDF: 11 pages
Proc. SPIE 0288, Los Alamos Conf on Optics '81, (30 December 1981); doi: 10.1117/12.932032

Published in SPIE Proceedings Vol. 0288:
Los Alamos Conf on Optics '81
Donald H. Liebenberg, Editor(s)