International Journal of Science, Engineering and TechnologyAuthors: Thai Ngoc Le, Vu Van Le, Ngo Nam Phuong
Abstract: Contemporary optical instrumentation constitutes a fundamental strategic asset in military surveillance and tactical operations, necessitating high operational efficiency across a broad spectrum of irradiance conditions, from peak diurnal intensity to low-light regimes. A significant technical challenge involves maintaining invariant image fidelity amidst extreme dynamic ranges in ambient illumination. This study investigates an innovative adaptive iris system designed to autonomously modulate the entrance pupil, thereby optimizing radiant throughput and mitigating aberrations. Utilizing the ZEMAX design environment, an opto-mechanical system was synthesized featuring discrete pupil diameters Dm of 2.8 mm, 3.5 mm, and 4.0 mm, tailored for photopic, mesopic (twilight), and scotopic conditions, respectively. The system's optical integrity was rigorously verified against four primary criteria: Modulation Transfer Function (MTF), Longitudinal Aberration, Field Curvature, and Geometric Distortion. Numerical simulations confirm that the system exceeds all performance benchmarks: the MTF values surpassed 0.4 at the targeted spatial frequency (exceeding the 0.2 threshold), longitudinal aberration was constrained below 0.03 mm, field curvature remained within the 1.318 mm tolerance, and distortion was limited to within ±0.5%. These findings demonstrate that the self-adjusting aperture configuration provides a robust and effective solution for multi-environment reconnaissance missions.
DOI: https://doi.org/10.5281/zenodo.18229020
