Abstract: The spatial distribution of gain has been investigated on the Research Assessment and Device Improvement Chemical Laser, a supersonic chemical oxygen-iodine laser (COIL). A frequency-stabilized, narrow linewidth diode laser system operating on the F $EQ 3 $YLD F $EQ 4 hyperfine levels of the ($+2$/P$-$HLF$/) to ($+2$/P$-3/2$/) spin-orbit transition in atomic iodine was used as a small signal probe. A peak gain of 1.2%/cm was measured along the horizontal centerline of the single-slit, supersonic nozzle is about two times greater than measurements made on ReCOIL and compares favorably with measurements made on the Rotating Disk Generator (RotoCOIL) device. Gain distribution was investigated under three I$-2$/ flow conditions. Scans across the supersonic expansion indicate a gradient in gain distribution due to higher gas temperatures along the walls and mixing phenomena.!12
展开▼
