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Continuous Wave Quantum Detection and Ranging with quantum heterodyne detection

Ming-Da Huang, Zhan-Feng Jiang, M. Hunza, Long-Yang Cao, Hong-Yi Chen, Yuan-Feng Wang, Yuan-Yuan Zhao, Hai-Dong Yuan, Qi Qin

Abstract

In the continuous-wave Detection and Ranging technology, simultaneous and accurate range and velocity measurements of an unknown target are typically achieved using a frequency-modulated continuous wave (FMCW) with a heterodyne receiver. The high time-bandwidth product of the FMCW waveform facilitates the optimization and high-precision of these measurements while maintaining low transmission power. Despite recent efforts to develop the quantum counterpart of this technology, a quantum protocol for FMCW that enhances measurement precision in lossy channels with background noise has yet to be established. Here, we propose a quantum illumination protocol for FMCW technology that utilizes sum frequency generation and an entangled light source with low transmission power. This protocol demonstrates a 3 dB enhancement in the precision limit for high-loss channels compared to classical approaches, independent of the background noise level. This precision limit is achieved through quantum heterodyne detection (QHD), followed by signal processing. Moreover, in classical approaches, QHD is only optimal in high-loss channels when strong background noise is present. In weak background noise scenarios, our protocol can further provides precision enhancements up to 6 dB over classical methods with QHD.

Continuous Wave Quantum Detection and Ranging with quantum heterodyne detection

Abstract

In the continuous-wave Detection and Ranging technology, simultaneous and accurate range and velocity measurements of an unknown target are typically achieved using a frequency-modulated continuous wave (FMCW) with a heterodyne receiver. The high time-bandwidth product of the FMCW waveform facilitates the optimization and high-precision of these measurements while maintaining low transmission power. Despite recent efforts to develop the quantum counterpart of this technology, a quantum protocol for FMCW that enhances measurement precision in lossy channels with background noise has yet to be established. Here, we propose a quantum illumination protocol for FMCW technology that utilizes sum frequency generation and an entangled light source with low transmission power. This protocol demonstrates a 3 dB enhancement in the precision limit for high-loss channels compared to classical approaches, independent of the background noise level. This precision limit is achieved through quantum heterodyne detection (QHD), followed by signal processing. Moreover, in classical approaches, QHD is only optimal in high-loss channels when strong background noise is present. In weak background noise scenarios, our protocol can further provides precision enhancements up to 6 dB over classical methods with QHD.

Paper Structure

This paper contains 1 section, 19 equations, 3 figures.

Table of Contents

  1. ACKNOWLEDGMENTS

Figures (3)

  • Figure 1: The angular frequency $\omega(t)$ of the Local signal and the return signal under the triangle frequency modulation with initial angular frequency $\omega_{0}$, modulation bandwidth $\Delta\omega$ and modulation period $T_{m}$. Here, $\tau = \frac{T_{m}}{2\Delta \omega} \frac{\omega_{b_{1}} + |\omega_{b_{2}}|}{2}$ and $\omega_{d} = \frac{\omega_{b_{1}} - |\omega_{b_{2}}|}{2}$, where $\omega_{b_{1}}$ and $\omega_{b_{2}}$ represent the frequency differences between the received and local FMCW signals for the rising and falling edges of the triangular frequency modulation, respectively.
  • Figure 2: Sketches of various FMCW illumination for simultaneous range and velocity measurement.
  • Figure 3: Comparison of QFIs and CFIs for FMCW illumination at different noise levels.