arXiv subjects

Meng Lon Iu

Publications and source records attributed to Meng Lon Iu.

4 recordsLinked to original sources

arXiv2025

Towards Arbitrary Time-frequency Mode Squeezing with Self-conjugated Mode Squeezing in Fiber

Optical parametric amplification generates squeezed light in device-specific sets of time-frequency eigenmodes, and it has been widely accepted that detection and utilization of squeezing must comply with this modal constraint. We show that this constraint can be considerably relaxed under the continuous-wave pump and broadband phase-matching approximation, where the modal decomposition is non-unique. Specifically, any time-frequency mode with "self-conjugated" spectral symmetry can approximate a squeezing eigenmode, and partial homodyne detection can herald squeezing in arbitrary time-frequency modes. We demonstrate this using a high-efficiency, low-loss all-fiber source, measuring 4.38 +- 0.11dB and 0.88 +- 0.09 dB squeezing on partially coherent and chaotic self-conjugated modes. Using a bichromatic self-conjugated mode with reduced local-oscillator noise, we achieve 7.50 +- 0.12dB squeezing, which represents the highest level reported for fully guided-wave squeezing sources based on chi(2) and chi(3) nonlinearities.

quant-ph↗

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↗

arXiv2022

Quantum and Non-local Effects Offer LiDAR over 40dB Advantage

Non-local effects have the potential to radically move forward quantum enhanced LiDAR to provide an advantage over classical LiDAR not only in laboratory environments but practical implementation. In this work, we demonstrate a 43dB lower signal-to-noise ratio using a quantum enhanced LiDAR based on time-frequency entanglement compared with a classical phase-insensitive LiDAR system. Our system can tolerate more than 3 orders of magnitude higher noise than classical singlephoton counting LiDAR systems before detector saturation. To achieve these advantages, we use non-local cancellation of dispersion to take advantage of the strong temporal correlations in photon pairs in spite of the orders of magnitude larger detector temporal uncertainty. We go on to incorporate this scheme with purpose-built scanning collection optics to image non-reflecting targets in an environment with noise.

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↗