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

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 –Si 3 N 4 (High Refractive Index) –SiO 2 (Low Refractive Index)

Experimental Details Base Pressure: 1.0 x torr RF Power Applied to Target: 150 Watts Silicon Target Microscope Slide Substrate Argon Environment O 2 and N 2 Reactive Gas (RG)

Analysis

N2N2 O2O2 N2N2 λ -2 (µm -2 ) λ (nm)

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 is gratefully acknowledged.