CO Laser

A molecular CO laser was the first laser to be pumped with nuclear radiation in experiments outside Russia with a pulsed reactor [143]. As with gas-discharge CO lasers, lasing was observed on vibrational-rotational transitions of the CO molecule with X = 5.1-5.6 qm. The pumping of carbon monoxide at a pressure of 0.13 atm and temperature of a 77 K was carried out using uranium fission fragments. The neutron source was an SPR-II pulsed reactor (see Chap. 2, Sect. 2.7). The output laser power was 2-6 W; the efficiency, determined in [143] with respect to the energy deposition to the volume of the principal mode, was 0.1-0.3 %. The small — signal gain at transitions 10-9, 9-8, and 7-6 of the CO molecule reached 5 x 10-3 cm-1 [144]. Study [51] reports that later on, the authors of [143, 144] obtained output power of around 100 W for CO NPLs using a multiple-path cavity with a 120-cm active length (see Fig. 2.2a).

Lasing at X ~ 5 qm of the CO molecule was also obtained in study [145] on exciting the mixture 3He-CO with nuclear reaction products 3He(n, p)3H. The output power at a mixture pressure of 3 atm was >200 W from an active volume of 300 cm3. The laser threshold was reached at ФгА = 3 x 1016 cm-2 s-1.