*Communication* **State-of-the-Art Technologies in Piezoelectric Deformable Mirror Design**

**Vladimir Toporovsky 1,\* , Alexis Kudryashov <sup>1</sup> , Arkadiy Skvortsov <sup>2</sup> , Alexey Rukosuev <sup>1</sup> , Vadim Samarkin <sup>1</sup> and Ilya Galaktionov <sup>1</sup>**


**Abstract:** In this work, two advanced technologies were applied for manufacturing a bimorph wavefront corrector: laser ablation, to vaporize conductive silver coating from piezoceramic surface, and parallel-gap resistance microwelding, to provide a reliable electrical contact between the piezodisk surface silver electrodes and copper wires. A step-by-step guide for bimorph mirror production is presented, together with the 'bottlenecks'. Optimization of the laser ablation technique was carried out using an Nd:YAG laser with an output power of 4 W and a frequency of 20 kHz. A comparison of the ultrasonic welding and parallel-gap resistance microwelding methods was performed. The tensile strength in the first case was in the range of 0.2 . . . 0.25 N for the system 'copper wire–silver coating'. The use of resistance welding made it possible to increase the value of this parameter for the same contact pair by almost two times (0.45 . . . 0.5 N).

**Keywords:** adaptive optics; deformable mirror; laser ablation; parallel-gap resistance microwelding; wavefront control
