Thin Film Optical Filter Fabrication and Characterization

1. Thin Film Optical Filter Fabrication and Characterization • Adam Hammouda, Kalamazoo College • Dr. David Shelton, UNLV 1

2. Overview • Arbitrarily Modulating the Refractive Index of a Thin Film Offers Novel Optical Filtration Qualities • Film Fabrication Performed with Reactive Magnetron Sputtering Deposition • Target Materials • Si3N4 (High Refractive Index) • SiO2 (Low Refractive Index)

3. Experimental Details • Base Pressure: 1.0 x 10-6 torr • RF Power Applied to Target: 150 Watts • Silicon Target • Microscope Slide Substrate • Argon Environment • O2 and N2 Reactive Gas (RG)

5. Analysis

7. N2 N2 O2 λ-2 (µm-2) 707 500 408 354 λ (nm)

8. λ = 532 nm λ= 633 nm

9. Best results: minus filter optimized for low transmission at 800 nm

10. Conclusion Successful fabrication of minus band -Design wavelength of 800 nm results in 5% Transmission It is not clear yet the nature of refractive index modulation -Further work must be done to establish this

11. Acknowledgements Dr. David Shelton, UNLV Dept. of Physics and Astronomy, mentor Mrs. Mahin Behnia, UNLV Chemistry Dept., for help with UV-VIS spectrophotometer. Support from the REU program of the National Science Foundation under grant DMR-1005247 is gratefully acknowledged.