The invention relates to the technical field of lasers, and discloses a dynamic thermal
focal length controllable module and a disc
laser, and the dynamic thermal
focal length controllable module comprises a
deformable mirror which is arranged on a light path of emergent
laser after being pumped by a
laser crystal and is used for generating a compensation
surface shape conjugated with aberration of the laser
crystal; the imaging
assembly is arranged on a reflection light path of the
deformable mirror, and
light intensity distribution of the emergent laser is obtained by measuring the emergent laser reflected by the
deformable mirror; and the closed-
loop control module calculates the variable quantity of the deformable mirror according to the
light intensity distribution, adjusts the deformable mirror according to the variable quantity, and compensates the thermally induced
surface shape error of the laser
crystal. According to the invention, the deformable mirror is used as a
phase compensation element, and the comprehensive aberration generated by a transmission element is converted into the
surface shape error of a single reflecting surface for characterization based on the self-adaptive optical principle. The surface shape of the deformable mirror is changed in a piezoelectric mode, it is ensured that the
surface type of the deformable mirror can accurately correct
wavefront distortion, introduced by the
surface type, of the disc laser crystal, and the problem of error accumulation in multi-interface interference measurement is solved.