Gain and continuous-wave laser power enhancement with a secondary discharge to predissociate molecular iodine in an electric oxygen-iodine laser

Abstract

Herein the authors report on the demonstration of a 50% enhancement in gain and 38% enhancement in continuous-wave laser power on the 1315nm transition of atomic iodine through the addition of a secondary discharge to predissociate the molecular iodine in an electric oxygen-iodine laser. In the primary discharge the O2(aΔ1) is produced by a radio-frequency-excited electric discharge sustained in an O2–He–NO gas mixture, and I(P1∕22) is then pumped using energy transferred from O2(aΔ1). A gain of 0.10%cm−1 was obtained and the total laser output power was 6.2W.

Recent advances in the development of discharge‐pumped oxygen‐iodine lasers

“…In the region of the laser cavity, the small signal gain increased from 0.067% cm to 0.1% cm when the I predissociation discharge was applied. The laser power was increased by 38% to 6.2 W. The efficiency advantage of using predissociation was illustrated by the observation that Benavides et al [89] obtained comparable laser powers by supplying 1000 W to the DSOG alone or 800 W distributed between the DSOG (700 W) and the predissociation discharge (100 W).…”

“…The advantages of I predissociation for DOIL were definitively demonstrated by Benavides et al [89] They used an RF discharge in a He/I mixture to generate I atoms immediately prior to injection into the primary flow. The DSOG for these experiments was driven using 700 W of RF power, and produced an O (a) yield of 15%.…”

Heterogeneous losses of externally generated I atoms for OIL

“…A dc discharge sustained in I 2 /N 2 gas mixture was used for iodine dissociation assistance in a supersonic COIL 3,4 . Discharge predissociated molecular iodine in an electric oxygen iodine 5,6 and all-gas-phase iodine laser 20 schemes provided significant increase in gain and laser power. Recently 11 , efficient dissociation of I 2 in a repetitively pulsed nanosecond discharge was reported.…”

“…Usage of an external iodine atom generator can improve energy efficiency of the oxygen-iodine laser (OIL) and expand its range of operation parameters [1][2][3][4][5][6][7] . Electric-discharge [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] and chemical [18][19][20] generators have been proposed as a source of iodine atoms for the use in OIL.…”

“…Electric-discharge [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] and chemical [18][19][20] generators have been proposed as a source of iodine atoms for the use in OIL. Dissociation of iodine-containing molecules in electric-discharge plasmas had been proved to be useful for external production of iodine atoms.…”