The invention discloses a
pyramid annular
resonant cavity, and solves technical problems in the prior art that a traveling wave cavity exerts precise requirements for the installation angle of a cavity mirror and cannot meet the application requirements in a severe environment. The main points of the technical scheme of the invention are that the
resonant cavity comprises a cavity, an active
laser material, a
pyramid prism and a unidirectional operation control device, wherein the active
laser material, the
pyramid prism and the unidirectional operation control device are disposed in the cavity; the interior of the cavity also comprises a high-reflection mirror for reflecting
fundamental frequency light, a cavity mirror for the output of modulated light and the reflection of
fundamental frequency light, a nonlinear
crystal, and a right-angle
prism; light beams, emitted by the active
laser material when the active laser material is activated by external pumping, vertically enter the right-angle prims and are reflected in a parallel manner; the light beams enter the nonlinear
crystal and then enter the cavity mirror at an angle of 45 degrees, and are reflected to the unidirectional operation control device; emergent light is reflected by the pyramid prism to return to the active laser material. The
resonant cavity reduces the requirements of the installation precision of all elements in a wall through the adjustment of the elements in the cavity, and meets the application requirements in a severe environment.