Entanglement-Assisted Joint Monostatic-Bistatic Radars

Abstract

With the help of entanglement, we can build quantum sensors with sensitivity better than that of classical sensors. In this paper we propose an entanglement assisted (EA) joint monostatic-bistatic quantum radar scheme, which significantly outperforms corresponding conventional radars. The proposed joint monostatic-bistatic quantum radar is composed of two radars, one having both wideband entangled source and EA detector, and the second one with only an EA detector. The optical phase conjugation (OPC) is applied on the transmitter side, while classical coherent detection schemes are applied in both receivers. The joint monostatic-bistatic integrated EA transmitter is proposed suitable for implementation in LiNbO₃ technology. The detection probability of the proposed EA joint target detection scheme outperforms significantly corresponding classical, coherent states-based quantum detection, and EA monostatic detection schemes. The proposed EA joint target detection scheme is evaluated by modelling the direct radar return and forward scattering channels as both lossy and noisy Bosonic channels, and assuming that the distribution of entanglement over idler channels is not perfect.

Keywords: entanglement; entanglement assisted detection; quantum radars; quantum sensing; radars.

Figure 1

The proposed EA joint monostatic-bistatic quantum radar technique.

Figure 2

The EA monostatic quantum radar.

Figure 3

The optical-parametric amplifier (OPA)-based EA target detection receiver.

Figure 4

Joint monostatic-bistatic LiNbO₃ technology-based integrated EA transmitter with transmit side OPC. PDC: parametric down conversion, OPC: optical phase-conjugation, PPLN: periodically poled LiNbO₃ waveguide, QM: quantum memory.

Figure 5

EA homodyne balanced detection receiver corresponding to the direct return/forward scattered components. The phase modulator is used to detect either in-phase or quadrature component of the OPC signal. Photodiode responsivity is set to 1 A/W.

Figure 6

Detection probability vs. SNR [dB] for different radar detection schemes for average number of thermal photons set to N_b = 10. The maximum tolerable FA probability is fixed to Q_FA = 10⁻⁶. The monostatic and bistatic idler channels are assumed to be ideal.

Figure 7

Detection probability vs. SNR [dB] for joint EA scheme for different direct return probe/forward scattered probe bosonic channel transmissivities T^(r) = T^(fs) = T. The maximum tolerable false alarm probability is fixed to Q_FA = 10⁻⁶. The idler channel is assumed to be ideal.

Figure 8

Detection probability vs. SNR [dB] for EA joint detection scheme for different idler channels transmissivities. The direct return probe/forward scattered probe bosonic channel transmissivities are fixed to T^(r) = T^(fs) = T = 0.05. The maximum tolerable false alarm probability is set to Q_FA = 10⁻⁶.

Figure 9

Detection probability vs. SNR [dB] for EA joint detection scheme for fixed idler channels transmissivity T⁽ⁱ⁾ = 0.9. The direct return probe channel transmissivity is set to T^(r) = 0.4, while the forward scattered probe channel transmissivity is varied T^(fs) ∈ {0.1, 0.4}. The maximum tolerable false alarm probability is fixed to Q_FA = 10⁻⁶.