Two-frequency passive mode locking in an iodine photodissociation laser

Partially summed Maxwell-Bloch equations were used to estimate the ultimate potentialities of the passive mode-locking regime in an iodine laser under single-frequency and two-frequency lasing conditions. In the case of two-frequency passive mode locking an experimental discovery was made and an explanation was given of the appearance, in the laser emission spectrum, of the combination frequencies ν₂₂ – Δν and ν₃₄ + Δν, where Δν is the spectral interval between ν₂₂ and ν₃₄.