Optics and Holography

Technical Background - Wave Nature of Light - Interference ~constructive ~destructive - Diffraction

Bragg Equation 2d sin(θ)=nλ

Types Reflection Transmission Reflection Hologram Sticker

Applications Counterfeit protection Data Storage Heads Up Display (fighter pilots)

Holographic Film Storage of holograms Refractivity Interference patterns Changes in transmittance properties Refractivity Speed of light in different mediums Bending light beams

Photorefractive Polymer Film Components Structure (A) Sensitizer (B) Dye molecules (C) Plasticizer (D) How it works Electrons mobilized Internal electrical fields created Dye molecules orient forming a diffraction grating A B C D - - -

Experimental Setup Light Source Beam Splitter Lenses and mirrors Film

Exp. Setup Cont’d

Data Collection Fine tuning Reading Hologram Digital Photography Beam Alignment Stability Exposure time Reading Hologram Digital Photography

B (brightness in McGees) Data Analysis ImageJ Software Mean Brightness Exponential Decay DATA TABLES For the “D” holograms t (time in seconds) B (brightness in McGees) 15 18.95 30 17.55 45 17.14 85 16.96 180 16.90

Data Analysis, cont’d Exponential Decay Degradation starts fast Slows down as time goes on

Data Analysis, cont’d Exponential Regression for “D” holograms B = 6.62e-.0803t + 17.0 Constant represents minimum brightness Root Mean Square Error: < 0.05

Data Analysis, cont’d Exponential Regression for “Russia” holograms B = 1.97e-0.024t + 2.36 RMSE < 0.07

Conclusion Organic films store holograms Measure decay: digital photography Future research More multiple holograms Data storage

Acknowledgements National Science Foundation Dr. David McGee Katy Rolfe Dr. James Fukanaga Melissa Yang Anthony Miller Nathaniel Woodward Jackie Haynicz

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