Design of adaptive piezo mirrors

Motivation

Deformable unimorph mirrors are successfully applied compensating thermal lensing for many years. This success is based on the simple mirror setup constructed from a piezoelectric disk, adhesively bonded on the rear of a passive mirror substrate on the one hand, and also on the utilization of standardized high-power compatible optical coatings.

Application of this deformable mirror in high power laser systems is enabled by compound loading. Compound loading relies on the homogeneous heating of the mirror assembly that compensates the laser induced membrane deformation.

Technology - thermo-mechanical design

• The deformable mirror is constructed on the basis of an LTCC multilayer substrate.
• The contact electrodes and the piezoelectric layer are applied to the rear side of the substrate using screen printing and then fused with the substrate.
• Connection of the activatable mirror membrane with the mirror mount using solderjet bumping.
• Use of parallel wafer-level technologies (screen printing, electroplating, LTCC substrate).
• Substitution of complex manual processes with more efficient production methods.
• Processing of the mirror surface using ultra-precise turning process.