REOSC PIXELATED AND ADVANCED IR COATINGS

Transcription

1 REOSC PIXELATED AND ADVANCED IR COATINGS October 19th, 2016

2 1. Safran Reosc Overview 2. Infra Red Optical Coatings for MTG and IASI-NG 3. Development of Infra Red Pixelated Coatings 2

3 1. Safran Reosc Overview 2. Infra Red Optical Coatings for MTG and IASI-NG 3. Development of Infra Red Pixelated Coatings 3

4 Safran Reosc Large optics Advanced thin films Precision Opto-mechanics Astronomy Energy Industry Space Location Staff Activity Position : Saint Pierre du Perray, 35 km south of Paris. : 130 Phd s, engineers & technicians. : High performance optics design, development & production : An SME, 100% subsidiary of Sagem, within SAFRAN Group Defence 4

5 From Design to Fab Mechanical Design Machining Optical Design AIT Thin Film Deposition From EUV to IR Asph. & freeform Lightweight Large aperture Accurate to nm Smooth to Å Robust to space Optical Metrology Polishing Ion Beam Figuring 5

6 Optical Thin Film Department 8 coating machines All coating types from 160 nm to 15.5 µm 7 Spectrophotometers FTIR microscope Cryo WFE and Spectral benches Photolithography 6

7 Optical Thin Film Solutions IR coating Coating for large mirrors Filters, Dichroics EUV coating Laser components Coating etching 7

8 Reosc IR coatings IR optics Near detector coatings Detector Optics close to detector High transmission (low absoprtion) Large band (2µ-16µm) AR on detector IR filter near / on detector Structure coatings Pixelated coating 8

9 1. Safran Reosc Overview 2. Infra Red Optical Coatings for MTG and IASI-NG 3. Development of Infra Red Pixelated Coatings 9

10 Optical Coatings for MTG and IASI-NG Meteosat Third Generation M1 Mirrors IASI-NG Telescope Mirrors Scan Mirrors Interferometer in KBr Spectral Separator Assembly Focal Plane Optics NIR/IR Filters 10

11 Transmission (%) Optical Coatings for MTG NIR / IR Filters and Windows Spectral Separator Assembly different filters from 1.38µm to 13.3µm - Qualified for 55K - More than 700 EM/FM Wavelength (nm) NIR 1380 NIR 1610 NIR 2250 IR IR IR IR IR IR IR IR Mirrors, Dichroics from VIS to IR, AR : 22 coatings on ZnS, ZnSe, CdTe, Si, Ge, CaF2, BaF2, SiO2 - QM coating on-going 11

12 Optical Coatings for IASI NG Interferometer in KBr Focal Plane Optics - Prism, windows, sperator in KBr with AR/protective coating from 3.5µm- 15.5µm - EQM coatings on-going - Mirors, dichroics, AR : 17 coatings on ZnSe, CdTe, Si, Ge, CaF2, SiO2 - EQM coating on-going 12

13 Transmission (%) Infra Red Optical Coatings for MTG and IASI-NG Advanced IR coatings have been developed : IR Filters from 3.8µm to 13.3µm with high rejection and accurate centring / width Wavelength (nm) NIR 1380 NIR 1610 NIR 2250 IR IR IR IR IR IR IR IR Full space qualification of IR large band AR, Dichroics, Mirror on ZnSe, ZnS, CdTe, Si, Ge, SiO2, Ge, CaF2, BaF2, KBr 13

14 Infra Red Coating What s next? Today s IR systems are : Bulky Costly Future missions may requires lighter, less expensive real-time multispectral systems 14

15 1. Safran Reosc Overview 2. Infra Red Optical Coatings for MTG and IASI-NG 3. Development of Infra Red Pixelated Coatings 15

16 History of near FPA coatings Stripe filters VIS/NIR up to 4 bands (PLEIADES ) Structured IR Filters SWIR/MWIR/LWIR (CSO 2012) Antireflective coatings on dectector (Sentinel 5 - µcarb ) Spatially variable NIR filter (ISRO program ) SWIR/MWIR Pixelized filter (Military Application ) 16

17 Development of Infra Red Pixelated Coatings Standard Solutions Pixelated Filters on Detector Vue MEB de la maquette 10 µm Filter Whell or spectral separator / Detector Bulky Costly Sometimes not realtime Miniaturization of multispectral solution Less expensive Easier to cool down 17

18 Characteristics infrared-thermography.com IR Detector Pixels µm In cryostat T=77-150K IR Filters (T>95% & T<0.1%) Fabry-Perot 2, 3, 4 cavities : layers Coating thickness 3-15 µm 18

19 Technical Challenges Coating adherence on exotic materials (HgCdTe, InSb) Thermal cycling: 77K 300K Humidity : 24h, 40 C, 95% HR Outgassing : 15d under vaccum, 90 C Dead pixels <1% BA9 Reduced coating deffects Reduced photolithographic deffects Crosstalk/diffraction Steepness of etching : thinnest coating, optimized etchnig process BA9 Filter/pixel alignement 19

20 T% Pixelated coating : qualification and FM manufacturing of a 2 IR band detector 20 Key features: Transmission rate >95% and <0.1% on specified bands Low surface defects rate: S defects < 1% Operating temperature 77K Environmental tests successful Humidity: 95%, 40 C, 48h Thermal shocks 77K 340K x 50 First FM manufactured Spectral function A Spectral function B SWIR-MWIR Wavelength

21 Pixelated coating : multibands prototyping Discrete filter matrix Linear filter Key features High accuracyof cavity thickness Compatible with IR-FPA technology Processes for discrete & continuous filtering N steps 2 N filters 21

22 Conclusions Multispectral / hyperspectral next missions can include : - Multispectral at detector level - Light and affordable multispectral / hyperspectral capabilities 22

23 Thank you! Contacts : Fabien PRADAL Optical Thin Film Manager fabien.pradal@safrangroup.com Roland GEYL VP Business Development roland.geyl@safrangroup.com 23