LADAR resolution improvement using receivers enhanced with squeezed-vacuum injection and phase-sensitive amplification

Abstract

The use of quantum resources—squeezed-vacuum injection (SVI) and noise-free phase-sensitive amplification (PSA)—at the receiver of a soft-aperture homodyne-detection LAser Detection And Ranging (LADAR) system is shown to afford significant improvement in the receiver's spatial resolution. This improvement originates from the potential for SVI to ameliorate the loss of high-spatial-frequency information about a target or target complex that is due to soft-aperture attenuation in the LADAR's entrance pupil, and the value of PSA in realizing that potential despite inefficiency in the LADAR's homodyne detection system. We show this improvement quantitatively by calculating lower error rates—in comparison with those of a standard homodyne detection system—for a one-target versus two-target hypothesis test. We also exhibit the effective signal-to-noise ratio (SNR) improvement provided by SVI and PSA in simulated imagery.