US 3,946,332 A · High power density continuous wave plasma glow jet laser system

Abstract

A high power density continuous wave (c. w.) gas dynamic laser system is described which includes a non-equilibrium plasma jet for generating excited gaseous species having high vibrational temperature and low gas temperature. Gas flow through the plasma jet is reduced to highly turbulent subsonic flow by an expanding nozzle. Lasing in an optical cavity oriented transversely with resspect to the flow of the gaseous plasma extracts vibrational energy from the excited gaseous species as the emerge from the expansion nozzle. The described system also includes, immediately upstream from the optical cavity, an injection system which introduces and uniformly mixes a lasing gaseous species into the highly turbulent subsonic gaseous plasma flow from the plasma jet. Gas sweeps are established in the arms of the optical cavity to cool and sweep high temperature unexcited gas species therefrom in order to reduce absorption in the optical cavity. The described laser system can be adapted for either open cycle or closed cycle operation depending upon the gaseous mediums utilized. A particular carbon dioxide - nitrogen gas dynamic laser system is described which has a gain coefficient of 32/m at 20 torr of carbon dioxide and 40 torr of nitrogen with an estimated power density of approximately 1000 W/cm.sup.3, a saturation parameter of approximately 2000 W/cm.sup.2 and an estimated overall efficiency of approximately 24 percent..

Claims53

Dependent claims

A high power density laser comprising in combination,

a. a gaseous medium,
b. means for inducing axially symmetrical supersonic flow of said gaseous medium,
c. means for establishing an electrical glow discharge having axial symmetry across said supersonic flow for converting said gaseous medium into supersonically flowing plasma and excited gaseous species having low translational temperatures and a population inversion therein, and,
d. means for stimulating the emission of radiation energy from said flowing plasma and excited gaseous species for producing a laser beam.

1 more element

A high power density laser comprising in combination,

a. a gaseous medium,
b. a cylindrical plenum having a structure defining an annular throat at one end axially aligned with the longitudinal axis thereof,
c. means tangentially introducing said gaseous medium into said plenum for inducing circular flow of said gaseous medium around the longitudinal axis of said plenum,
d. means for pumping said gaseous medium from said plenum through said throat at supersonic velocities, whereby a stable supersonic vortex flow of said gaseous medium is established,
e. means for establishing an axially symmetric electrical glow discharge across said stable supersonic vortex flow of said gaseous medium for converting said flowing gaseous medium into flowing plasma and excited gaseous species having low translational temperatures and a population inversion therein,
f. means for stimulating the emission of radiation energy from said flowing plasma and excited gaseous species for producing a laser beam.

3 more elements

A high power density laser comprising in combination,

a. a gaseous medium,
b. a cylindrical plenum having a structure defining an annular throat at one end, axially aligned with the longitudinal axis thereof,
c. means tangentially introducing gaseous medium into said plenum for inducing circular flow of said gaseous medium around the longitudinal axis of said plenum,
d. means for pumping said gaseous medium from said plenum through said throat at supersonic velocities, whereby, a stable supersonic vortex flow of said gaseous medium is established.
e. means for establishing an axially symmetric electrical glow discharge across said stable supersonic vortex flow of said gaseous medium for converting said flowing gaseous medium into flowing plasma and excited gaseous species having low translational temperatures,
f. a gaseous lasing species,
g. means for introducing said lasing species into said flowing plasma and excited gaseous species, whereby, a population inversion is excited in a lasing energy state of said lasing species by collisional interaction with said plasma and excited gaseous species,
h. means for stimulating the emission of radiation energy from said excited lasing species for producing a laser beam.

5 more elements

Dependencies are inferred from the claim text.

High power density continuous wave plasma glow jet laser system

Life of this patent

High power density continuous wave plasma glow jet laser system

Life of this patent

Abstract

Claims53