Extremely Narrowband Sodium Line Filter For Daytime Adaptive Optics

THE OBJECTIVE OF THIS RESEARCH IS TO SEE IF AN EXTREMELY NARROWBAND SODIUM FARADAY ATOMIC LINE FILTER CAN BE USED TO ALLOW ADAPTIVE SYSTEMS USING A SODIUM LASER GUIDE STAR TO WORK UNDER DAYTIME LIGHT CONDITIONS FOR APPLICATIONS SUCH AS IMAGING SATELLITES. THE POTENTIAL APPLICATIONS OF THE FILTER TECHNOLOGY ARE BASED ON THE EXTREMELY SMALL BACKGROUND LIGHT ACCEPTANCE BANDWIDTH OF THE FILTER (ABOUT .005 nm), ITS POTENTIAL FOR THROUGHPUT EFFICIENCIES (INCLUDING POLARIZATION LOSSES) OF AROUND 30%, AND THE FACT THAT ITS TRANSMISSION BAND OVERLAPS A SOLAR FRAUNHOFER LINE WITH AN ADDITIONAL FACTOR OF 20 REDUCTION IN BACKGROUND LIGHT. CALCULATIONS OF DAYTIME ADAPTIVE OPTICS SYSTEM PERFORMANCE USING THE FILTER WILL BE CARRIED OUT, AND A FILTER APPROPRIATE FOR AN ADAPTIVE OPTICS SYSTEM WILL BE DESIGNED AND BUILT. THE FILTER WILL BE TESTED FOR THROUGHPUT, OUT OF BAND REJECTION, AND SPECTRAL RESPONSE TO VERIFY ITS PREDICTED PERFORMANCE.