Factors influencing the applications of active heterodyne detection. (November 2021)

• Record Type: Journal Article
• Authors: Liu, Yutao; Gao, Mengdie; Zeng, Xiaodong; Liu, Feng; Bi, Weihong
• Is Part Of: Optics and lasers in engineering. Volume 146(2021)
• Publication Date: 2021-11
• Subjects: Heterodyne detection -- Decoherence effect -- Target speckle -- Atmospheric turbulence -- Optical system aberrations -- Pahse mismatches; Lasers in engineering -- Periodicals; Optical measurements -- Periodicals; Optics -- Periodicals; Lasers en ingénierie -- Périodiques; Mesures optiques -- Périodiques; Optique -- Périodiques; 621.36605
• DOI: 10.1016/j.optlaseng.2021.106694
• Languages: English
• ISSNs: 0143-8166

Abstract

Highlights: A method for modeling the performance of a heterodyne system in presence of target speckle, atmospheric turbulence, or optical system aberrations is presented. The impact of three sources of signal degradation (target speckle, atmospheric turbulence, and optical system aberrations) on heterodyne detection is discussed. A high-speed camera heterodyne system was developed to evaluate the effectiveness of the genetic algorithm for correcting spatial phase mismatches in applications involving active heterodyne detection. Abstract: Heterodyne efficiency reflects the matching states of phase and amplitude between a local oscillator (LO) beam and a received signal beam and is, therefore, an indicator of system performance. Many factors can cause sensitivity degradation or decoherence in active heterodyne detection applications, such as target speckle, atmospheric turbulence, and optical system aberrations. This paper presents a method for calculating the heterodyne efficiency by mixing LO and customized signal beams in the plane of the detector surface. Results show that the heterodyne efficiency is fixed if the amplitude distribution of the signal light obeys a certain distribution, but the phase mismatches can significantly degrade the system sensitivity. Furthermore, a high-speed camera heterodyne system was developed to evaluate the effectiveness of genetic algorithms for correcting the spatial phase mismatch in applications involving active heterodyne detection. The array detector method improves the heterodyne system sensitivity and benefits active detection applications such as Synthetic Aperture Ladar, Laser Vibrometry, and Long-range Coherent Ladar.