Abstract
In this paper, we experimentally demonstrate the impacts of laboratory vibrations and laser flicker noise on digital holography (DH). Specifically, we measure both the vibration efficiency and the coherence efficiency of our DH system at various focal-plane array integration times and path-length differences between the signal and reference. These efficiencies, in practice, contribute to the overall mixing efficiency, which is a measure for how well the detected signal and reference interfere. The results show that when the integration time is ≤1ms, the laboratory vibrations are negligible with a vibration efficiency of 100%; however, when the integration time equals 100 ms, the laboratory vibrations lead to a 94% vibration efficiency. In addition, the results show that the effective coherence length of the master-oscillator (MO) laser increases by 280% when the integration time decreases from 100ms to 100 $\mu \text{s}$ . To account for this outcome, we present a model of the coherence efficiency based on the frequency noise of the MO laser. The model fit to the DH data then shows that the frequency of the MO laser is flicker-noise dominated. As a result, decreasing the integration time improves the overall mixing efficiency because of high-pass filtering in both the vibration efficiency and the coherence efficiency. Based on previous published efforts, these results have direct ties to the achievable signal-to-noise ratio of a DH system.
Highlights
A PPLICATIONS of digital holography (DH) are diverse with significantly different system requirements
We presented a complete model for the mixing efficiency of a DH system to account for vibrational and laser frequency noise effects
At zero path length difference between the signal and reference, we observed the mixing efficiency decreased for the longest integration time, which we attributed to vibrations (94%)
Summary
A PPLICATIONS of digital holography (DH) are diverse with significantly different system requirements. The path-length differences between the signal and reference are nearly matched and do not limit the achievable signal-to-noise ratio (SNR) due to the coherence length of the light source. These applications often use laser sources with a short coherence length [1], [2] or even incoherent light sources [3]. For tactical applications, where the DH system is on a moving platform, external factors, such as vibrations, will degrade performance. Understanding the effects of coherence and vibrations in terms
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
