Analysis of CW Oxygen-Iodine Laser Performance Using Similarity Criteria

A simplified single-frequency two-level model for predicting power extraction from a CW oxygen-iodine laser (OIL) considering relaxation losses has been developed. The model predicts that the energy efficiency of CW OILs with stable resonators depends on three similarity criteria. Criterion γ_d is the ratio of the residence time of active medium in the resonator to the singlet oxygen O₂(¹triangle) energy extraction time at an infinite intraresonator intensity. Criterion Π is small-signal gain to the threshold ratio. Criterion Λ is the relaxation to excitation rate ratio for the electronically excited iodine atoms I(²P_1/2). The analysis of the calculated and experimental data show that effective power extraction from the CW OIL active medium is achieved when the values of the similarity criteria are in the ranges: γ_d=4-6, Π = 3-8, and Λ ≤ 0.01.