Research on the phase-locking and beam characteristics of a new axisymmetric-fold-combination CO2 laser

A new type of axisymmetric-fold-combination CO2 laser, which is constituted by several axisymmetric four-mirror cavities, is studied theoretically in this paper. The mutual energy coupling occurring within the communal discharge region of the unstable resonator to inject seed signals into each sub-resonator is demonstrated by theoretical deduction. The numerical results have proved that phase-locking could be achieved in this cavity, and the beams with phase-locking have both a higher intensity and a smaller light spot than the ones without phase-locking.

► We model a new kind of axisymmetric-fold-combination CO2 laser with phase-locking. ► The output beam of the CO2 laser is fundamental transverse mode. ► We explain and calculate the effect of phase-locking in this CO2 laser. ► The overall efficiency and the beam quality of this CO2 laser are excellent.