Digital Holography Efficiency Experiments for Tactical Applications
Technical Report,01 Sep 2016,12 Sep 2019
AIR FORCE INSTITUTE OF TECHNOLOGY WRIGHT-PATTERSON AFB OH WRIGHT-PATTERSON AFB United States
Pagination or Media Count:
Digital holography DH uses coherent detection and offers direct access to the complex-optical field to sense and correct image aberrations in low signal-to-noise environments, which is critical for tactical applications. The performance of DH is compared to a similar, well studied deep-turbulence wavefront sensor, the self-referencing interferometer SRI, with known efficiency losses. Wave optics simulations with deep-turbulence conditions and noise were conducted and the results show that DH out preforms the SRI by 10s of dB due to DHs strong reference. Additionally, efficiency experiments were conducted to investigate DH system losses. The experimental results show that the mixing efficiency 37 is the dominate efficiency loss however, excess reference noise 75 and excess signal noise 3-100 are significant efficiency losses as well. Further experiments show DH effectively quantifies laser coherence as an efficiency to within or - 3.2 of the spectral models and the observed laser coherence can be dependent on the hologram integration time. The observed laser linewidth was reduced 65 by decreasing the integration time from 100 ms to 100 mu s, thus filtering laser frequency noise and increasing the effective system range by 280.
- Radiofrequency Wave Propagation