Development of a UHV-Compatible Absorptive Coating for Implementation in MAGIS-100

The bedrock of light pulse atom interferometery is light-atom interactions. As such, it is crucial to ensure the quality of the laser wavefront that interacts with the atoms. One source of wavefront imperfections can come from diffracted beams entering the interferometry region, such as those spawned by aberrations from optics. The metallic surface of the inner tube is reflective– thus creating the potential scenario in which diffracted beams propagating at an angle reflect off those surfaces and interfere with the main beam. One solution to this problem is to apply an absorptive coating on the interior of the interferometry tube. However, a critical constraint is the outgassing properties of any absorptive coating applied– MAGIS-100 is aiming for a base pressure of 1 × 10−11 Torr over the 100m. In this talk, I will discuss our efforts to develop effective coatings for this application.