Quantum-enhanced ladar ranging with squeezed-vacuum injection, phase-sensitive amplification, and slow photodetectors

Abstract

Theory has shown [1] that the quantum enhancements afforded by squeezed-vacuum injection (SVI) and phasesensitive amplification (PSA) can improve the spatial resolution of a soft-aperture, homodyne-detection laserradar (ladar) system. Here we show they can improve the range resolution of such a ladar system. In particular, because an experimental PSA-enhanced system is being built whose slow photodetectors imply multi-pulse integration, we develop range-measurement theory that encompasses its processing architecture. We allow the target to have an arbitrary mixture of specular and speckle components, and present computer simulation results demonstrating the range-resolution improvement that accrues from quantum enhancement with PSA.