Carbon dioxide laser with sequential transitions and a composite resonator

An analysis is made of the problem of selection of sequential transitions (00⁰v₃→[10⁰v₃–1, 02⁰v₃–1]) in CO₂ lasers. A new method is proposed in which sequential transitions are selected using a composite resonator formed by a diffraction grating and a diffraction reflecting interferometer. In contrast to a CO₂ laser with a heated cell, the use of a composite resonator makes it possible to construct a more compact sequential CO₂ laser and to ensure rapid switching of lasing between the main and sequential transitions. Measurements are reported of the gain for the main and sequential transitions and of the populations of the CO₂ molecular levels.