SWAP DM: preliminary design and schematics of a DM for extreme adaptive optics

Transcription

1 SWAP DM: preliminary design and schematics of a DM for extreme adaptive optics Funding: Teresa Kopf, M.Eng. Claudia Reinlein 1, Teresa Kopf 1, Andreas Kamm 1, Christoph Damm 1, Oliver Dietzel², Benjamin Dargatz 2, Stefan Richter², Klaus Süßmuth², Mathias Bach², Bernd Broich² 1 Fraunhofer Institute for Applied Optics and Precision Engineering, Germany ² Physik Instrumente GmbH & Co. KG, Germany

2 Fraunhofer Institute for Applied Optics and Precision Engineering IOF About 7000 m² floor space 204 Employees + 72 Students Budget 2014: 25,0 mn. (45 % industry projects) Design & Simulation Optical & Precision Engineering Components Manufacturing Optomechanical Systems Integration Application Page 2

3 1. Background Active and Adaptive Optics Group Design and manufacturing of various deformable mirrors 40 actuator high power DM for laser communication > 6 kw cw focussing DM DM for cryogenic applications AO system design Design and implementation of a real-time portable AO box for laser communication WFS design Long term stable Giant DM Cylindrical Mirror High Power Focus Mirror HP endurance DM Page 3 HP: High Power DM: Deformable Mirror

4 Structure 1) Requirements 2) Schematics 3) Preliminary Design 4) Breadboards 5) Summary and Outlook Page 4

5 Structure 1) Requirements 2) Schematics 3) Preliminary Design 4) Breadboards 5) Summary and Outlook Page 5

6 Requirements Mirror surface Ring-shaped mirror Activated outer diameter 450 mm Passive inner diameter 108 mm Reflectivity nm nm Mirror roughness < 1.5 nm rms Mirror surface flatness Defocus <2 µm PtV High order modes Σ (Z5-Z11) <2 µm PtV after subtraction of modes with PZT activation 10 nm rms Page 6

7 Requirements Actuation Capability 11,000 actuators within the aperture Actuator pitch of 3.7 mm Bidirectional activation ±1.5 μm Interactuator stroke 1.2 µm Compensation for hysteresis and non-linearity Initial failure rate 5 stacks (out of 11,000) Replaceable actuator units SWAP DM Page 7

8 Structure 1) Requirements 2) Schematics 3) Preliminary Design 4) Breadboards 5) Summary and Outlook Page 8

9 Schematics Actuator selection Usage of PICMA stack actuators High force generation High resolution Full-ceramic insulation for long lifetime and increased reliability Small foot prints avaliable Exchangeability of actuator modules Repairable with minimum disassembly Page 9

10 Schematics Technical Principle Mirror 3.7 mm Pin Support structure 1.2 µm 1.2 µm >1.2 µm Spring Piezoelectric stack Bottom plate Wiring Page 10

11 Schematics Schematic System Design Front view Side view 3 x 120 Bipod flexures Mirror Shell Page 11

12 Structure 1) Requirements 2) Schematics 3) Preliminary Design 4) Breadboards 5) Summary and Outlook Page 12

13 Preliminary Design Actuator Properties Increasing module size fewer modules need to be installed Number of actuator modules over the actuators per module larger force acting on the bottom plate and its fixation thickness of the support structure vs. degree of acentricity Actuator modules of 4 x 4 actuators Acentricity of < 60% Page 13

14 Preliminary Design Actuator Properties Calculation of the working point at 48 V 7,2 µm 0 N force down to 0 µm at 125 N 2 µm bias-stroke 2.2 µm additional stroke to initially flatten mirror surface Page 14

15 Structure 1) Requirements 2) Schematics 3) Preliminary Design 4) Breadboards 5) Summary and Outlook Page 15

16 Breadboards Manufacturing Process of Modules Top Piezo stack Holder Module base plate Page 16 Goals: Evaluation of: Manufacturing accuracy Gluing process of piezo stack with holder Handling and alignment procedure Electrical contacting

17 Breadboards Gluing of the mirror surface Pulling direction Tool for tensile test Substrate fixation Glass substrate Plate Soft layer Table of pulling machine Goals: Evaluation of: Dosing parameters Adhesive tensile strength Gluing process (alignment, processing time, ) Page 17

18 Breadboards Assembling, testing and exchanging of modules Goals: Evaluation of manufacturing, alignment and assembly procedures Functional demonstration of stroke Swap modules Page 18

19 Structure 1) Requirements 2) Schematics 3) Preliminary Design 4) Breadboards 5) Summary and Outlook Page 19

20 Summary Analysis of the requirements Development of the technical principle based on requirements Further development from the technical principle to the preliminary design Identification of critical technologies Definition of breadboards Outlook Tests of the breadboards until end of 2017 Assembly of a mirror demonstrator with 3 x 3 modules Technology is available from mid-2018, could be adapted to your needs! Page 20

21 Thank you for your attention! SWAP DM: Ø 450 mm 11,000 actuators Actuator pitch 3.7 mm Interactuator stroke 1.2 µm Update rate 4 khz Visit us at our info-table! Page 21