High-contrast power resonances in a linear two-mode He–Ne/J2 laser

The first report is given of the attainment of high-contrast resonances in a linear two-mode ³He–²²Ne laser (λ = 0.63 μ) with an internal ¹²⁹J₂ absorption cell. The maximum contrast ratio of these resonances was 25% and their width was the same as that of similar resonances in the single-mode regime within the measurement error.