Title: Lidar Orbital Angular Momentum Sensor
Presenting Author: Carl Weimer
Organization: Ball Aerospace & Technologies Corporation
Co-Author(s): Yongxiang Hu, NASA Langley Research Center; Jeff Applegate and Mike Lieber, Ball Aerospace & Technologies Corporation

Abstract:
A revolution in our understanding of light is occurring across optical sensing areas including exoplanet research, optical communication, optical tweezers, adaptive optics, and turbulence sensing. The revolution has been powered by 1) the recognition that all electromagnetic waves carry angular momentum not only in the form of polarization (or spin angular momentum SAM), but also in the form of orbital angular momentum (OAM), and by 2) technologies developed to manipulate this new degree of freedom. While John Poynting first derived the general angular momentum equations in 1909, it wasnt until the 1990s that researchers explored the implications, especially for light. This field is undergoing dramatic growth as the theory, its implementation, and associated technology is developed. The overarching goal of the LOAMS effort is to apply these OAM manipulation techniques to lidars through the design of unique beam parameters and receiver angular momentum discriminators (mode sorters). One objective is to explore the possibility of controlling the beam/atmosphere interactions. A second is to provide a new method for additional rejection of sunlight. The LOAMS project will tackle these challenges by combining laboratory and field demonstrations, instrument modeling, and scattered-field finite-difference time domain (FDTD) electromagnetic field numerical modeling of the interactions of beams with OAM and atmospheric constituents. This presentation will report on the first six months of the effort. Effort is funded under NASA ESTO ACT Grant #NNX15AB32G