Abstract: An apparatus and method for minimizing gas density perturbation within an optical region of a gas dynamic laser to improve the optical quality of the output laser is disclosed. Gas disturbance generators disposed intermediate the throat region of the nozzle and the optical region are adapted for producing a disturbance to the flow to oppose flow density disturbances resulting from shock or expansion waves emanating from the intersection of the ends of the nozzle and side walls. In one embodiment the gas disturbance generator is a protrusion into the gas path. A further embodiment utilizes a jet of gas into the gas path to produce the disturbance. A further embodiment utilizes suction along the side wall to produce the disturbance. The optical quality of the laser energy passing across the gas flow is significantly improved.

Abstract: A high power gas dynamic mixing laser capable of having an energizing gas formed by an exothermic decomposition process is disclosed. The laser includes a housing having a reaction chamber in which an excitation gas is formed by thermal decomposition of a starting material, a nozzle connected to the housing for expanding the excitation gas to supersonic velocity, means for injecting a lasing gas into the supersonic stream of excitation gas to produce an inversion of populated energy levels of the lasing gas, optical means for extracting a laser beam and exhaust means for passing the gas mixture to the atmosphere. An embodiment of the present invention includes a return duct attached at one end to the exhaust means and at the other end to the housing for circulating the gas through the laser and a lasing gas capable of thermal decomposition downstream the optical means to form the excitation gas.

Abstract: This device includes an expander open cycle gas dynamic laser wherein the majority of the gas dynamic laser flow is recirculated while a fraction of the flow is removed in a boundary layer bleed removal system. This device includes a combustor for providing the proper gas constituents which then flow downstream of a nozzle means in a laser cavity to permit lasing to occur. The flow from the lasing cavity is directed into a diffuser which in turn directs its flow into the inlet of a compressor after flowing over a heat exchanger which cools the flow. One heat exchanger is in the bleed flow while the other is in the flow from the diffuser. The flow from the compressor is directed into the combustor.