Methods for spectral selection in the region of the 2P1/2–2P3/2 transition in an iodine atom under conditions of lasing in a Zeeman inhomogeneous gain profile

An experimental and theoretical analysis was made of several possible frequency selection methods suitable for the ²P_1/2–²P_3/2 transition in an ¹²⁷J atom under lasing and amplification conditions. The application of an inhomogeneous magnetic field gave rise to a spectral inhomogeneity of the gain. It was found that a relatively stable single-frequency emission of laser radiation was possible in an inhomogeneous magnetic field. A proposal was made for a selection cell based on resonant absorption by atomic iodine in the ²P_3/2 state when subjected to a magnetic field. An experimental study was made of the spectral selection properties of the active medium under lasing conditions. Relative (compared with Ar) values were obtained for the broadening constants of a luminescence line amounting to 1.3±0.1 for Xe and 2.0±0.3 for CO₂ and SF₆.