Investigation of emission characteristics of a photodissociation thallium laser

Abstract

Results are reported of investigations of the spectral and energy properties of the emission of a thallium laser on the transitions 7S1/2-6P3/2 (λ = 535 nm) and 7S1/2-6P1/2 (λ = 377.6 nm). Excited thallium atoms are produced in dissociation of the TII molecule by radiation from an ArF laser (I = 193 nm). The experiments were performed with two cavity types, to make possible operation with lasing at one or two wavelengths. In the case of operation with one wavelength, the emission spectrum at λ = 535 nm consists of the hyperfine structure components of two isotopes T1203 and T1205 whose frequency difference depends on the emission flux density in the cavity. At the λ = 377.6−nm wavelength the isotopic structure of the line is not manifested, since the isotope shift is small compared with the Doppler width. When two wavelengths are generated, it is observed that when a certain flux density is reached the emission structure is qualitatively altered, with unequal changes in the character of the emission spectra of the different lines. The results are discussed.