RAMAN COVERTED MID-IR LASER

THE OBJECTIVE OF THIS PROPOSAL IS THE DEVELOPMENT OF A PULSED MID-IR LASER IN THE 3.5 TO 4.1 MICROMETER ATMOSPHERIC TRANSMISSION WINDOW. SUCH SPECTRAL SOURCE IS RELEVANT TO A VARIETY OF TACTICAL APPLICATIONS. THE DF CHEMICAL LASER HAS BEEN THE CHOICE, BUT SUFFERS FROM WASTE FUEL MANAGEMENT PROBLEMS. NO OTHER EFFICIENT DIRECT LASING SOURCE IS AVAILABLE. TO OBTAIN SUCH A SOURCE, WE PROPOSE THE USE OF 1.06 MICROMETER (ND LASER) AND A COMBINATION OF RAMAN SHIFTING GASES SUCH AS HYDROGEN, HYDROGEN HALIDES AND THEIR ISOTOPIC MEMBERS. THIS APPROACH IS FEASIBLE DUE TO CURRENT IMPROVEMENTS IN THE EFFICIENCY OF ND ION LASING IN GGG HOST CO-DOPED WITH CR ION, AND THE DEMONSTRATED EFFICIENCY OF THE RAMAN SHIFTING PROCESS. THE KEY TO THE ATTAINMENT OF THE DESIRED WAVELENGTH BAND IS THE MAGNITUDE OF THE GAIN COEFFICIENTS OF THE PROPOSED HALIDE GASES. THE PRIMARY TASK OF THIS PHASE I EFFORT IS THE DEMONSTRATION OF POTENTIAL EFFICIENT CONVERSION IN THESE GASES. SYSTEM DESIGN FOR A PHASE II PROTOTYPE SYSTEM WILL ALSO BE CONDUCTED.