arXiv subjects

Amr S Helmy

Publications and source records attributed to Amr S Helmy.

3 recordsLinked to original sources

arXiv2023

Compact All-Fiber Quantum-Inspired LiDAR with > 100dB Noise Rejection and Single Photon Sensitivity

Entanglement and correlation of quantum light can enhance LiDAR sensitivity in the presence of strong background noise. However, the power of such quantum sources is fundamentally limited to a stream of single photons and cannot compete with the detection range of high-power classical LiDAR transmitters. To circumvent this, we develop and demonstrate a quantum-inspired LiDAR prototype based on coherent measurement of classical time-frequency correlations. This system uses a high-power classical source and maintains the high noise rejection advantage of quantum LiDARs. In particular, we show that it can achieve over 100dB rejection (with 100ms integration time) of indistinguishable(with statistically identical properties in every degrees of freedom) in-band noise while still being sensitive to single photon signals. In addition to the LiDAR demonstration, we also discuss the potential of the proposed LiDAR receiver for quantum information applications. In particular, we propose the chaotic quantum frequency conversion technique for coherent manipulation of high dimensional quantum states of light. It is shown that this technique can provide improved performance in terms of selectivity and efficiency as compared to pulse-based quantum frequency conversion.

quant-ph↗

arXiv2021

A $χ^{(2)}$-based AlGaAs Phase Sensitive Amplifier with Record Gain, Noise and Sensitivity

Phase sensitive amplifiers (PSAs) have the potential to empower substantial advances in emerging generations of optical communication systems as well as classical and quantum on-chip signal processing. The core building block of a PSA is a nonlinear medium. While the second-order nonlinearity ($χ^{(2)}$) is stronger than the third-order nonlinearity ($χ^{(3)}$), it is used less often in semiconductors for parametric amplification owing to the challenges of effectively phase matching the interacting waves as well as two-photon absorption of the pump. In this work, we demonstrate the successful design, fabrication, and characterization of the first $χ^{(2)}$-based semiconductor PSA using an efficient phase matching approach and a pulsed pump, based on an aluminium gallium arsenide (AlGaAs) waveguide platform. Non-centrosymmetric semiconductors such as AlGaAs offer appreciable $χ^{(2)}$. Such waveguides also achieve more than one order of magnitude greater pump field confinement when compared to other materials with large $χ^{(2)}$ such as Periodically Poled Lithium Niobate (PPLN). Our AlGaAs PSA achieves an on-chip in-phase gain, a sensitivity of 0.005 photons per pulse, and approaches theoretical minimal noise figure (NF) of 0~dB. With the capability of operating on signal states with sub-single photons per pulse, our PSA could usher in a new era of on-chip quantum circuits.

physics.optics↗

arXiv2020

Electrically-Reconfigurable Passive and Active Circuits in a Single Plasmonic Architecture

Guided-wave plasmonic circuits are promising platforms for sensing, interconnection, and quantum applications in the sub-diffraction regime. Nonetheless, the loss-confinement trade-off remains a collective bottleneck for plasmonic-enhanced optical processes. Here, we report a unique plasmonic waveguide that can alleviate such trade-off and improve the efficiencies of plasmonic-based emission, light-matter-interaction, and detection simultaneously. Through different bias configurations, record experimental attributes such as normalized Purcell factor approaching 10^4, 10-dB amplitude modulation with <1 dB insertion loss and fJ-level switching energy, and photodetection sensitivity and internal quantum efficiency of -54 dBm and 6.4 % respectively can be realized within the same amorphous-based plasmonic structure. The ability to support multiple optoelectronic phenomena while providing performance gains over existing plasmonic and dielectric counterparts offers a clear path towards reconfigurable, monolithic plasmonic circuits.

physics.optics↗