Ultralight Weight Optical Systems using Nano-Layered Synthesized Materials Natalie Clark, PhD NASA Langley Research Center and James Breckinridge University of Arizona, College of Optical Sciences
Overview Nanolayer Synthesized Materials Diffractive Telescope System Adaptive Optics Beam Steering Tunable Spectral Filters Applications - Intelligent Star Tracker System - Optical Communications - Spectro-polarimeter - Coronagraph Summary
Intelligent Optical Systems Objective: Facilities: Develop an intelligent active optic devices and integrated systems with novel active optic devices that can be individually controlled to modulate irradiance, phase, polarization and spectral properties of light. Class 100 clean-room, rapid prototyping, grinding/polishing, optomechanical design & proto-typing, VLSI design, PCB board fabrication, flex circuit fabrication, MCM design tools, HV CMOS, custom Active Pixel focal plane arrays Devices: LC Devices Fabry Perot Etalon Array Deformable Mirrors Custom Active Pixel Sensors Systems: Contact: Dr. Natalie Clark n.clark@larc.nasa.gov Wavefront Sensor System on a chip IntelliStar: Intelligent Star Tracker
Advanced Sensors and Optical Metrology Photonics Fabrication Laboratory 1k x1k Phase SLM Class 100 Active Optics Tech Active Pixels Liquid Crystals Deformable Mirror Programmable Lenses Wavefront sensors Bump Bonding Devices Tunable Filters - Etalons - Liquid Crystal Wavefront Modulator Lenses/Mirrors Detectors Space Environment Shutter And wave plates Tunable Filters
Diffractive Optical Telescope System Concept Objects of Interest Objective (Diffractive Optic) IMU Focal Plane DOE Tunable Filter Fast Steering Mirror/AO Telescope Objective - Diffractive - Thin plate/membrane - Nano-layer fabrication Diffractive Optical Element (DOE) - Application Specific - Broad band - Polarization - Nano layer fabrication Tunable Filter Tunable Etalon Array Adaptive Optic - Wavefront Compensation - Beam Steering Inertial Measurement Unit (IMU)
Diffractive Optical Telescope Objective Optical Parameter Mathematical Expression Zone Radius rr nn 2 = 2nnnnnn + nn 2 λλ 2 Zone Width Dispersion Resolution Spot Size Depth of focus (DOF) Bandpass Δλλ ww = λλλλ 2rr nn Δλλ = 2λλ2 ff DD 2 rrrrrrrrrrrrrrrrrrrr = 1.22λλ DD Δ = 1.22λλλλ DD DOF = ± 2Δ2 λλ Δλλ = 2λλ2 ff DD 2
Diffractive Optical Telescope Objective: Focal Length versus wavelength Focal Length: - Depends on Process - Shorter focal lengths require higher resolution process -Lower (faster) F number (f/d) require shorter focal lengths or larger diameter
Diffractive Optical Telescope Objective: Depth of Focus
Diffractive Telescope Objective: Fabrication
Diffractive Telescope Objective: Image Performance Diffraction Limited Image Of USAF Tri-Bar pattern Telescope Objective H-alpha filter Focusing lens Collimating lens 24.1 mm Focal plane array
Adaptive Optics: LCOS Device Cell Type Electronic controlled Phase Shifter Active Area 20 mm x 15mm Resolution 1024x768 Fill Factor 96.0% Bit Depth 8 bit (256 gray scale) Temporal Bandwidth 60 Hz Effective Stroke Length Liquid Crystal Layer Uniformity Operation Wavelength Beam Steering Range Steering Accuracy 635nm 1/10 to Valley at 632.8 nm 632.8nm +/- 4 mrad on both X and Y axis Steering Efficiency > 80.3% Better than 10 urad
Adaptive Optics: Interferometry using the LCOS Device
Far Field Beam Compensation
Tunable Spectral Filters Array Elastomer Fabry Perot Array
Tunable Etalon: Fabrication and Performance Evaluation
IntelliStar: Intelligent Star Tracker APPS Array Silicon Carbide Housing Corrector Optic MEMs Micro-Mirrors Optic Axis Silicon Carbide Housing Star Primary Mirror Catadioptric Telescope: - Wide FOV Silicon Carbide Housing: - Light weight - Small Thermal effects MEMs Micromirrors - Enhanced accuracy Active Pixel Position Sensors - High Accuracy - Low Power Intelligent Vision Processor - High Bandwidth - Controls - Massively Parallel Architecture Algebraic Coding Theory - Enhanced Pattern Recognition - Massively Parallel Technique.
Star Tracker/IMU Performance Sensitivity +1 to +6 Aperture Weight 68 mm.75 kg Number of stars tracked 1 to 5 Angular accuracy 7 micro- radians FOV 20 degrees (full frame sensor) Update rate Output 10 Hz Quaterion
NASA Applications Guidance Navigation and Control -- Achromat Adaptive Optics -- Novel APS tracker Imaging Sensor Chronograph -- Achromat Phase shifter -- Holographic coatings Optical Communications: -- Spiral phase shifter -- Tracking independent of wavelength -- Adaptive Optics
Summary Systems Approach - Tops Down/Bottoms Up - Modular open architecture High Precision Active Optics - Class 100 clean room - Rapid Prototyping - Opto-Mechanical Systems Design Batch Processing - Reduces labor for unique prototypes - Reduce cost per unit in multiple prototypes - Can transition to mass production Strategic Partnering/Leveraging Resources - NASA - Other Agencies - Academia - Industry