The SiF chemical laser

Abstract

Strong emission signals in the micron region, derived from a confocal cavity and monitored in the time-domain following the pulsed irradiation of SiCl₄ in the presence of F₂ and excess of He, have been observed which are suggested to arise from stimulated emission, SiF(a⁴Σ^–)→ SiF(A²Σ⁺)+hv (λ= 1.4 µ); population of SiF(a⁴Σ^–) is considered to result principally from the reaction of the electronically excited silicon atoms, Si(3¹D₂, 3¹S₀)+ F₂ in the context of recent absolute rate measurements for these optically metastable atomic states.