ABSTRACT
An advanced annular resonator is studied both theoretically and experimentally. This resonator has a Cassegrain mirror configuration and is designed to extract circular and high-quality beams from annular gain media. We carried out beam propagation in this resonator, calculating the intensity distributions of the laser beam. We also proved the performance experimentally by applying the resonator to a CO2 laser. The operation of the new resonator is demonstrated successfully. The quality of the output beam is in good agreement with theoretical calculations of laser output power of 20 W.
ABSTRACT
A novel resonator, the Gauss-core resonator, based on a stable resonator configuration designed to yield a highly focusing beam operating in a large-volume TEM(00) mode, is presented. A 6.2 kW linearly polarized output beam with an M(2) factor of 1.7 is obtained experimentally for a high-power cw CO(2) laser. The capability of the Gauss-core resonator to process laser materials is also studied. We can cut 1-mm-thick mild (soft) steel with a maximum cutting speed of 58 m/min at 5.6 kW and 0.2-mm-thick steel 145 m/min at 2.8 kW.
ABSTRACT
A novel cavity design based on a stable resonator configuration is presented. The output coupler of the new stable resonator has a circular partial-reflection region in the center that is surrounded by an antireflection region. This resonator operates in a large-volume TEM(00) mode that is mainly determined by the partial-reflection region of the output coupler and is characterized by the use of an additional laser beam that is spread from the optical path in the cavity because of diffraction and is amplified by a laser medium. By combining part of a beam transmitted from the partial-reflection region with the amplified diffraction beam, a laser beam having a large diameter is obtained. A diffraction-limited output beam with the M(2) factor of 1.3 is obtained, as predicted theoretically when the new stable resonator is applied to a high-power cw CO(2) laser.
ABSTRACT
A polarization-sensitive two-dimensional wave-optics simulation was constructed to handle the birefringence of strongly pumped solid-state rods. The simulation showed that 1.2 times diffraction-limited high-quality beams can be generated from a strongly pumped solid-state rod by use of an unstable resonator without degradation of the beam quality by the thermally induced birefringence in the rod.
