Integrated Optical Receiver for Communication and Fine Tracking in Inter-Satellite Links

Abstract

Inter-satellite optical links demand high-precision fine tracking while preserving sufficient received power for data communication, yet these functions are often treated separately at the receiver. This paper proposes a dual-function optical receiver that integrates data reception and fine tracking on a shared, intentionally defocused receiver plane. The architecture combines a central data lens with an annular four-segment tracking detector, creating a fundamental tradeoff between datapower collection and angular-estimation capability. A scalar Fresnel wave-optical model is developed together with nonlinear two-dimensional calibration and a noise-aware worstcase angular-accuracy framework. The receiver geometry is then jointly optimized to maximize the guaranteed fine-tracking range subject to a minimum data-power constraint. Results demonstrate that appropriate co-design of the central aperture and defocus substantially enlarges the usable fine-tracking region while maintaining the required communication-path power. The proposed framework provides a receiver-level benchmark for analyzing and designing integrated communication-and-tracking architectures in future optical inter-satellite terminals.