||Kirtland Air Force Base, NM 871175776
|Robert Lee Johnson
AFRL/RDSS, Starfire Optical Range (SOR), located at Kirtland AFB, New Mexico, USA, has recently started collaborative research with the National Institute for Astrophysics (INAF), which is an Italian research institute in astronomy and astrophysics. The goal of this collaborative research is to use adaptive optics to pre-compensate a sodium laser to form a smaller beacon, which would make it more effective for adaptive optics. SOR is seeking a postdoc to lead this international research effort.
Sodium beacons are widely used in adaptive optics as a means to estimate wavefront distortions caused by propagation of light from the source (e.g., a star or a satellite) through the atmosphere. However, the laser beam that forms the sodium beacon is distorted by atmospheric turbulence as it travel upwards from the telescope, which creates a beacon that is larger and less coherent. The reduced coherence decreases the sensitivity of the wavefront measurement. Adaptive optics techniques can be used to pre-correct for the atmospheric distortion on the laser beam, thus increasing the beacon coherence and the sensitivity of the resulting wavefront measurement.
The postdoctoral researcher will conduct research and development in the area of pre-compensation of sodium-wavelength lasers to improve their ability to form sodium beacons in the mesosphere. The postdoctoral researcher will define, plan, and conduct laboratory and field experiments. The postdoctoral researcher will also develop wave-optics models, perform experiments, analyze data, document research results, present findings at scientific conferences, and publish findings in peer-reviewed scientific journals. The postdoctoral researcher will collaborate with international partners, thus overseas travel will be necessary. Experience is sought in the areas of 1) laser-beacon adaptive optics, 2) laser beam control, or 3) atmospheric lidar. A combination of laboratory experience and on-sky field test experience is desirable.
1. J. Drummond, J. Telle, C. Denman, P. Hillman, J. Spinhirne, and J. Christou, “Photometry of a Sodium Laser Guide Star from the Starfire Optical Range. II. Compensating the Pump Beam,” Publications of the Astronomical Society of the Pacific 116, no. 824 (2004): 952–64; doi: 10.1086/425595
2. J. Huang, K. Wei, K. Jin, M. Li, and Y. Zhang, “Controlling the Laser Guide Star power density distribution at Sodium layer by combining Pre-correction and Beam-shaping,” Opt. Comm. Vol. 416 (2018): 172–180
3. R. Holzlöhner, D. Bonaccini Calia, and W. Hackenberg, "Physical optics modeling and optimization of laser guide star propagation," Proc. SPIE 7015, Adaptive Optics Systems, 701521 (10 July 2008); doi: 10.1117/12.790907
4. D. Bonaccini Calia, M. Centrone, E. Pinna, D. Alaluf, N. Martinez, J. Osborn, W. Hackenberg, M. Townson, M. Faccini, A. Di Paola, L. F. Rodriguez Ramos, R. Speziali, M. Reyes, P. Janout, D. Jenkins, D. P. Wei, T. Fischer, J. Perdigues, W. R. L. Clements, "CaNaPy: SatComm LGS-AO experimental platform with laser uplink pre-compensation," Proc. SPIE 11852, International Conference on Space Optics—ICSO 2020, 118521A (11 June 2021); doi: 10.1117/12.2599233
sodium-laser beacon; sodium-laser guide-star; adaptive optics; laser-beacon adaptive optics; uplink laser pre-compensation; uplink laser pre-correction;