Disc Laser Cavity With Zig-Zag Optical Path for Compact High Power

The patent transitions from a two-dimensional slab geometry to a three-dimensional folded cavity geometry within a cylindrical volume. The beam path is folded multiple times between spherical mirrors, creating a compact volumetric structure that achieves long optical paths without requiring large planar dimensions. This dimensional transformation allows high power output while maintaining compactness.

The patent embeds multiple beam passes and optical reflections within a single cylindrical cavity volume. The folded cavity design nests the optical path length within the physical structure by having the beam traverse the cavity multiple times in a folded pattern, effectively packing a long optical path into a compact volume similar to nested dolls.

The patent segments the optical path into multiple discrete passes between the spherical mirrors. Each pass contributes to the total optical length, and the segmented approach allows the long path to be achieved through repetition of a simple mirror-to-mirror traversal rather than a single complex optical element.

The spherical mirrors serve multiple functions: they define the cavity geometry, provide the folding surfaces for the beam path, and act as the optical resonator elements. This multi-functionality reduces the need for additional specialized components, thereby managing complexity while achieving the long optical path.

The patent employs RF (radio frequency) excitation instead of static DC excitation, introducing dynamic electromagnetic fields to drive the laser medium. This dynamic excitation mechanism enables much higher power output compared to DC excitation, while the resonant nature of RF coupling allows efficient energy transfer.

The RF excitation operates at periodic radio frequency cycles, creating oscillating electromagnetic fields that resonate with the laser medium. This periodic action at high frequency enables continuous energy deposition and sustains high power output, overcoming the limitations of static DC excitation.