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Presented by: Dr. Richard Billmers Triple Take Holographics For Holo -pack Holo -print 2012. A multispectral Approach to Hologram Security. Presentation Roadmap. 1. Introduction - Who are we? 2. Previous Work in Volume Holography 3. Salient Features of Security Holograms
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Presented by: Dr. Richard Billmers Triple Take Holographics For Holo-pack Holo-print 2012 A multispectral Approach to Hologram Security
Presentation Roadmap 1. Introduction - Who are we? 2. Previous Work in Volume Holography 3. Salient Features of Security Holograms 4. Concept for M.S. Approach to Holographic Security 5. Advantages of this M.S. Approach 6. Summary and Conclusions
Introduction – Who We Are • Collaboration of Triple Take Holographics and RL Associates Inc. • TT has been doing HOE and display holography development for over 20 years. • RL Associates has been doing HOE development for 15 years • Both are mainly design and prototype development companies. Mostly gov’t (DOD, NASA and Homeland Security) funded under R&D programs. • Both of our business models would be to develop this process and then license it to a much larger holographic production company.
Lidar Receiver with 2-Element Filter Delivered Prototype March 2011 • Volume Holographic array near the focal plane of large aperture mirror • Beam shaping with spherical holograms • Light from wide FOV reflected as collimated beam • Second narrowband element filters collimated light • Filtered light focused to small area detector. Operating Wavelength: 473 nm Spectral Bandpass: 0.12 nm, FWHM Clear Aperture (Array): 45 mm diameter Efficiency: 50% Out-of-Band Blocking: 10-4 Field of View (@ Primary): 3.5° at 16.5” aperture
Optical Design of Lidar Receiver • Parabolic Primary Mirror • SPDT, Ni-plated Al • 420mm CA, f/0.9 • Coated for 400-550nm • Holographic Array (Secondary) • 1027 elements, 1.49mm diam. • 127 multiplexed elements • Array Spherical-planar Geometry • Tailored to field near focal plane of 16.5” primary mirror • ~20° FFOV per element • Aft optics include: • Narrowband filter • 1/99 Beamsplitter • 2x 8mm PMTs
Holographic BeamsplittingApproach • Current Approach: Interference filters • Passes wavelength of interest/blocks all other wavelengths • One filter in front of each camera • Inefficient and uses multiple lens systems (1 for every camera) • Holographic Approach • Split the incoming white light • All light is captured • 5-6x more efficient & single lens system with same zoom on all channels
12 channel Beamsplitting Element Demonstrated Beamsplitter Characteristics Operating spectrum: 450 – 800 nm Number of spectral channels: 12 Spectral bandpass/channel: 15-25 nm, Field of view of system: 20-25 deg. Efficiency: 65-75% Aperture of system: 2” x 2” Aperture of each grating: ½” square Out-of-Band rejection: 10-2 Photo of 12 channel beamsplitter element
4.8” (122 mm) View Through Aperture of Turret Mount Shell inside turret, 5.1”Ø CH1 (above) CH2 (below) Sensors: Active Area, blk Chip, gold 5.1” (130 mm) Step Zoom Lens System Mux’d VHOE Muxed VHOEs, behind vis. sensors Zoom Lens system (shared), Apt: 2”Ø CH3 (below) CH4 (above) Cross-section 5 Channel MSI: 3 underwater/1 surface & MWIR • Multispectral Imager using 4 volume multiplexed reflective holograms • 3 blue/green channels for underwater detection • 1 red channel for surface reflection • MWIR Channel w/shared lens system MWIR Sensor
On board processing Visual Image Photos courtesy of JMMES program, NavAir, EO Sensors division and BAE Systems, Honolulu, HI
Salient Features of Holography in Security Use of Holograms as a Security device for 30+ years Relied on the rarity of the specialized skills and knowledge Expensive, custom-built equipment needed These limitations diminished as the process became a recognised industry Skills and process could be learned on the internet Equipment is more common and cheaper To continue to combat anti-counterfeiting in the digital age, security aspects of holography have to become more sophisticated
Three Types Security Features of holograms: Overt security 2. Covert Security 3. Tamper Evident All three are specifically mentioned in the new ISO 12931 Authentication Standard for Material Goods
Categories of Security Features of holograms: Overt security hologram is instantly visible Image is recognizable Unique look is difficult to emulate by non-holographic means However, if copied holographically, even a poor copy will pass a casual inspection
Categories of Security Features of holograms: Covert security Features embedded within the hologram Not clearly visible, but may be discovered Security relies on general ignorance of their existence or how to reveal them As given features are used, their existence becomes more widely known, possibly diluting their status as covert
Categories of Security Features of holograms: Covert security - examples Hidden Imagery Laser viewable only Requires knowledge of correct laser angle to display Best revealed using custom display reader Micro-structures Microscopic designs recorded directly onto the surface can be seen with loop or microscope Dot matrix images with shaped dots Hybrid: Electron beam images which replay with a laser beam
Categories of Security Features of holograms: Covert security - examples (cont.) Hidden Geometric Variations altering the geometry or shape of dots in a dot matrix can be discovered with microscope but not easily copied Luminescent overlays dyes that glow under UV color-tuning film overlay
Categories of Security Features of holograms: Tamper Evident - examples Exists within the structure of the material Does not show in the hologram, covert Revealed when tampering occurs, becoming overt
The essence of any security feature is incumbent in: Difficulty of reproducing by unauthorised user Simplicity of decoding by genuine user Cost and ease of implementation of the feature Most Present methods satisfy criteria independently Some may be mutually exclusive – Most of the time the more complex the feature, the more complex is the implementation More complexity typically means that it is more costly to design, build and implement.
Possible Applications for Multispectral Holographic Security Banknotes Credit Cards Material Goods - as per ISO 12931 Pharmaceuticals Printed Store or Manufacturers’ Coupons Document Security
Multispectral Approach - The Concept Multiple diffraction gratings are recorded in the same volume in a patch configuration. All gratings are recorded with same laser. Each grating is tuned so that a specific incoming angle/wavelength combination is reflected in a known geometry. Planar or spherical. The number of gratings recorded is variable depending on the level of security required. Furthermore gratings can be spherical to focus at some given distance. This is just another level of security. The gratings are read-out and verified using a set of LED’s (not laser) at specific wavelengths. The reflected light is detected by a set of PIN or similar diodes at very specific angles and distances (for spherical gratings). 4. A set of very simple electronics (voltage comparators. AND/OR gates) would then determine automatically if the proper signals were incident on the proper detectors
Advantages of a Multi-Spectral Approach • Satisfies all three criteria above • Difficult for unauthorised duplication • # of source / detector combinations goes up factorially • Combinations can be exclusive, or changed easily • Decoded using a simple, inexpensive reader that would provide a YES/NO answer with no additional skills or training required of the operator. • Can be mass-produced with equipment already available and present levels of training.
Conclusion We believe we have developed a method of recording a security feature on holograms that is simple and cheap to implement, simple to use in the detection of fraudulent product, and highly flexible so that the security aspect can be easily customized.
Triple Take Holographics would like to thank our partner R. L. Associates, Inc for their support in this project Thank You