OOFELIE::Multiphysics 2014 INDUSTRIAL MULTIPHYSICS DESIGN FOR OPTICAL DEVICES
INTRODUCTION 2
High precision opto-mechanics A VERY HIGH ACCURACY IN THE PRODUCTION OF MIRRORS AND LENSES IS NOW VERY OFTEN AVAILABLE THE SAME KIND OF ACCURACY IS MANDATORY IN THE (ELECTRO-)MECHANICS FOR MOUNTING AND CONTROLS 3
Harsh environment MECHANICAL LOADS, E.G. GRAVITY EFFECTS Large terrestrial telescopes Space optics THERMO-MECHANICAL EFFECTS Global temperature changes, thermal gradients, radiative transfers,... Difference of thermal expansion coefficients stresses and deformations PIEZOELECTRIC & ELECTROSTATIC ACTUATORS Astronomy Medical imaging Laser applications Telecommunication... 4
Active & adaptive optics HIGH-RESOLUTION IMAGING Astronomy (telescopes) Microscopy Ophthalmic imaging DEFORMABLE MIRRORS IN LASER TECHNOLOGIES Laser beam correction and shaping (laser micromachining, laser beam welding, ) Laser mode control and focussing (optical fibers, free space optics) Data storage in optical disks SIMULATION OF ACTUATORS BASED ON THE EFFECTS: Piezoelectric Electrostatic Electromagnetic 5
Design of complex optical systems Optical performance prediction & optimization complete design process Structural & thermal analyses Deformation Stress Temperature field Electro-mechanical effects (e.g. piezoelectric) Optical post-treatment Thermo-optic effect (dn/dt) GRIN Strain/stress induced birefringence Optical response analyses (ray-tracing software) 6
OOFELIE::MULTIPHYSICS FOR OPTICAL DEVICES 7
OOFELIE Multiphysics Multiple Physical Couplings Result selection and visualization in OOFELIE::UI Multiple analysis types Statics (Linear & Non-Linear) Modal (Real & Complex) Harmonic Transient (Linear & Non-Linear) Random Vibration 8
OOFELIE::MULTIPHYSICS FOR OPTICAL DEVICES APPLICATION EXAMPLES 9
LED Fluid-Structure Thermal Simulations 7 parts 3 cavities 12W applied 10
LED Fluid-Structure Thermal Simulations Temperature Velocity Filters on velocity 1st cavity 2nd cavity 3rd cavity 11
Lightweighted Mirror Temperature distribution Displacements 12
Electrostatics Micro Lens Simulations FEM/BEM COUPLING USING FMM (With courtesy of University of British of Columbia and British Columbia Cancer Research Centre, CANADA) 13
Infra Red - Micro-Bolometer Simulations Bridge and arms in Silicon nitride, 0.3 µm thick Electrical conductor in Vanadium, 0.1 µm thick Active layer in Vanadium oxide (VOx), 0.1 µm thick Parametric model Accounting for the temperature dependent thermal resistivity of the active layer 14
Infra Red - Micro-Bolometer 0.1 µw of IR light absorbed in the bolometer pixel Applied current: 5 µa Electrical potential Nodal temperature Nodal displacements 06/11/2014 Tokyo Seminar - MEMS 15
OOFELIE::MULTIPHYSICS COUPLED TO ZEMAX 16
Integrated Design Process OOFELIE Multiphysics analyses Deformation, stress, temperature OOFELIE Optical post-processing Optical surface aberrations, refractive index change Redesign model Dynamic Data Exchange ZEMAX Optical analyses Optical response 17
Combining multiphysics and optical models Structural model in OOFELIE::UI Optical model in ZEMAX Sag correction process Ensuring compatibility and no loss of accuracy due to CAD file transfers 18
Combining multiphysics and optical models STRESSES DEFORMATION CHANGE OF REFRACTIVE INDEX OPTICAL PERFORMANCES FULLY ANALYZED IN THE ZEMAX MODEL UPDATED BY OOFELIE 19
Mechanical deformations exported to ZEMAX SEVERAL EXPORTATION HYPOTHESES ACCOUNTING FOR TRANSVERSE NODAL DISPLACEMENTS DESCRIBING SURFACE DEFORMATION AS Zernike Standard Sag or Zernike Fringe Sag Grid Sag RIGID BODY MOTION RECOGNITION & SEPARATION (OPTIONAL) Complete deformation RBM removed Surface deformation exported to ZEMAX 20
Coupling with the Non Sequential mode of ZEMAX Heating due to light: AUTOMATED THERMAL LOAD DEFINITION IN OOFELIE BY USE OF 2D IRRADIANCE AND 3D ABSORPTION MAPS FROM ZEMAX 21
VALIDATION EXAMPLES 22
Spherical Lens Test Bench BICONVEX SPHERICAL LENS MADE OF BK7 BLACK ANODIZED ALUMINIUM MOUNT 2 HEATERS GLUED ON THE MOUNT 3 THERMOCOUPLES ON THE MOUNT TC1 Heater 2 TC2 Heater 1 TC3 (CSL IS AUDITED AS A TEST CENTRE FOR ESA) 23
Spherical Lens Test Bench INTERFEROMETRIC MEASUREMENTS Spherical lens Interferometer Mirror Spherical caliber F/3.3 24
Validation THE SUM OF THE 2 CALCULATED DEFOCI IS VERY CLOSE TO THE MEASUREMENTS Measured and calculated defocus (µm) 80.00 70.00 60.00 50.00 40.00 30.00 20.00 10.00 df_measured df_total calculated df_thermal_calculated df_grad_calculated 0.00 20.5 31.00 37.00 46.50 50.10 58.40 Temperature at centre of lens ( C) 25
Validation SIMULATED VS EXPERIMENTAL TEMPERATURE INSIDE THE LENS Temperature in lens center ( C) 60 55 50 45 40 35 30 Experimental results Simulation results 25 20 20 30 40 50 60 70 80 90 Temperature on mount ( C) 26
Validation THERMO-MECHANICAL STRESSES AND DEFORMATION OF A LENS IN A MOUNT 27
Validation BETTER ACCORDANCE BY ACCOUNTING FOR REFRACTIVE INDEX GRADIENT Focus aberration 20 30 40 50 60 70 80 0-0.1-0.2 Example of wave front error Z2,0 (waves @ 633 nm) -0.3-0.4-0.5-0.6-0.7 Experimental results -0.8-0.9 Simulation results 1 Simulation results 2 Temperature ( C) Simulation 1: thermomechanical gluing Simulation 2: thermomechanical contact 28
OOFELIE::MULTIPHYSICS COUPLED TO ZEMAX APPLICATION EXAMPLES 29
Space instrument MSG: GERB TELESCOPE EUMETSAT - RAL Tokyo Seminar - Open Engineering 30
Piezoelectricity - MEMS Micro-Mirror Simulations PZT actuators, 3 µm thick Mirror substrate, torsion bars and frame in Silicon, 50 µm thick Al layer, 0.3 µm thick PZT actuators, 3 µm thick 31
Piezoelectricity - MEMS Micro-Mirror optimization Modal analysis Rotation resonant mode at 15997 Hz Harmonic analysis Dynamic analysis (and exportation to ZEMAX): Complete deformation Elastic deformation 32
Vibration and dynamic responses DAMPING DUE TO A VISCOUS FLUID MEDIUM SURROUNDING VIBRATING STRUCTURES CAN BE MODELED BY USE OF THE BOUNDARY ELEMENT METHOD (BEM) Air speed around an air damped micro-mirror THE DYNAMIC BEHAVIOR OF A STRUCTURE CAN BE COMPUTED FROM A HARMONIC ANALYSIS OPTICAL SURFACE DEFORMATION CAN BE EXPORTED TO ZEMAX FOR OPTICAL PERFORMANCE ANALYSES
European Extremely Large Telescope Mirror segment active control mechanisms
E-ELT primary mirror Control One segment modeling & control laws Meshed model Deformation due to the excitation of one actuator 35
CONCLUSION 36
Multiphysical modeling Stress, deformation, vibration Temperature Structural Piezoelectric Conduction, convection, radiation Thermal Interface program Electrokinetics Electrostatic, electromagnetism Surface deformation, Stress-birefringence, Refractive index gradient Optical analyses Structural optimization Wavefront aberration, Modulation transfer function,... MULTIPHYSICAL ANALYSES FINITE ELEMENT METHOD & OPTICAL DESIGN SOFTWARE 37
OOFELIE::Multiphysics Key Features INTEGRATED CAE ENVIRONMENT ENGINEERING STANDARD, INTUITIVE, TIME-SAVING DESIGN FLOW INCLUDING SCRIPTING, PARAMETERIZATION AND OPTIMIZATION. STRONGLY COUPLED MULTIPHYSICS COMBINED WITH ZEMAX YIELDS FASTER AND MORE ACCURATE CONVERGENCE IN DYNAMICS BROAD OPTICAL SENSORS DOMAIN COVERAGE EFFICIENT HANDLING OF SUPERSIZED STRUCTURE AND FLUID PROBLEMS
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