Gain on the green excimer band (λ∼504 nm) of the iodine dimer has been observed in electron-beam-pumped mixtures of Ar (or Ne), and hydrogen iodide. A peak gain coefficient of γ>1.1% cm-1 is measured at 506 nm with a tunable dye laser and the full width at half-maximum (FWHM) of the gain spectrum in Ar diluent is 13 nm. Temporally resolved gain and fluorescence measurements show that the green emission originates from an I2 ion pair state other than D′. However, strong collisional coupling between the upper states of the UV (λ=342 nm) and green bands and superfluorescence on the UV band (I34 2∼2 MW cm-2) appear to limit the green gain coefficient to <20% of its small-signal value. Consequently, suppression of superfluorescence on the UV D′→A′ bands of the homonuclear halogens should lead to a new family of excimer lasers with wavelengths extending from the green into the ultraviolet.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)