Hypersonic gasdynamic laser system

Abstract

A visible, or near to mid infra-red, hypersonic gasdynamic laser system incorporated in a hypersonic vehicle which provides high enthalpy ram air for thermodynamic excitation of the laser gases. The hypersonic vehicle defines therein a laser cavity, and ram air directed therethrough supports gasdynamic lasing operations at wavelengths less than 10.6 .mu. meters. An optical train collects the laser radiation from the laser cavity and directs it as a substantially collimated laser beam to an output aperture defined by an opening in the hypersonic aircraft too allow the laser beam to be directed against a target. The present invention is particularly applicable to a hypersonic vehicle powered by a supersonic combustion ramjet engine. Electrical energy is also produced on-board the vehicle, using ram air, or ram air plus fuel combustion, as the power source and an electrical turbogenerator (or another equivalent electrical generator) connected to a supersonic turbine. Electrical energy from the electrical generator is supplied to a plurality of excitation electrodes positioned along the laser cavity walls of the laser cavity, to provide an electric field for electrical excitation of the lasing gases flowing through the laser cavity. A laser frequency agility control circuit is coupled between the electrical generator and the excitation electrodes, for controlling the electrical power and voltage supplied to the electrodes and the electric field generated thereby. This in turn controls the energy of the electrons introduced into the laser cavity, and thereby the wavelengths of laser radiation produced therein. Another significant feature of the subject invention is the provision of gas additive injection nozzles positioned near the entrance to the laser cavity to inject a lasing influencing gas, such as CO, NO, HCl or CS, into the airflow through the laser cavity, to influence lasing operation in the laser cavity.