Range Emulator: A Compact Paraxial Optical System to Emulate Long-Distance Monochromatic Laser Propagation

Emulating long-distance light propagation on a laboratory scale is essential for the ground-based testing of intersatellite optical systems. To address this challenge, we propose and analyze a novel optical system called the Range Emulator (RE) to reproduce the spatial propagation effects of a long-distance beam within a compact apparatus. Our analysis identifies that three lenses are required as the minimum number of lenses to implement the RE. Through a numerical exploration, we quantify the fundamental trade-off between system compactness and manufacturing precision. This work provides a practical framework for designing compact optical testbeds for future multi-satellite laser link technologies.