Biomedical imaging

Noise-tolerant single photon sensitive three-dimensional imager

Active imagers capable of reconstructing 3-dimensional (3D) scenes in the presence of strong background noise are highly desirable for many sensing and imaging applications. A key to this capability is the time-resolving photon detection that distinguishes true signal photons from the noise. To this end, quantum parametric mode sorting (QPMS) can achieve signal to noise exceeding by far what is possible with typical linear optics filters, with outstanding performance in isolating temporally and spectrally overlapping noise. Here, we report a QPMS-based 3D imager with exceptional detection sensitivity and noise tolerance. With only 0.0006 detected signal photons per pulse, we reliably reconstruct the 3D profile of an obscured scene, despite 34-fold spectral-temporally overlapping noise photons, within the 6 ps detection window (amounting to 113,000 times noise per 20 ns detection period). Our results highlight a …

P Rehain, YM Sua, S Zhu, I Dickson, B Muthuswamy, J Ramanathan, ...

Interaction-free all-optical switching in χ(2)microdisks for quantum applications

We propose a quantum switch for telecom-band applications that is composed of a χ^(2) microdisk coupled to two fibers (or waveguides). The idea is to apply a pump pulse to shift the microdisk out of resonance, thereby switching the device between the cross and bar states in an interaction-free manner. As an example, a 2.5-μm-thick, 10μm radius GaAs microdisk with an intrinsic Q of ∼10^8 and a fiber-cavity-coupling Q of ∼10^4 can achieve low-loss (≲1%) switching for gigahertz-rate O-band quantum signals with milliwatt-peak-power pumps in the C band.

YP Huang, P Kumar

Mode-selective image upconversion

We study selective upconversion of optical signals according to their detailed transverse electromagnetic modes and demonstrate its proof of operation in a nonlinear crystal. The mode selectivity is achieved by preparing the pump wave in an optimized spatial profile to drive the upconversion. For signals in the Laguerre–Gaussian modes, we show that a mode can be converted with up to 60 times higher efficiency than an overlapping, but orthogonal, mode. This nonlinear optical approach may find applications in compressive imaging, pattern recognition, quantum communications, and others, where the existing linear optical methods are limited.

S Kumar, H Zhang, S Maruca, YP Huang

Single-pixel pattern recognition with coherent nonlinear optics

In this Letter, we propose and experimentally demonstrate a nonlinear-optics approach to pattern recognition with single-pixel imaging and a deep neural network. It employs mode-selective image up-conversion to project a raw image onto a set of coherent spatial modes, whereby its signature features are extracted optically in a nonlinear manner. With 40 projection modes, the classification accuracy reaches a high value of 99.49% for the modified national institute of standards and technology handwritten digit images, and up to 95.32%, even when they are mixed with strong noise. Our experiment harnesses rich coherent processes in nonlinear optics for efficient machine learning, with potential applications in online classification of large-size images, fast lidar data analyses, complex pattern recognition, and so on.

T Bu, S Kumar, H Zhang, I Huang, YP Huang

Non-invasive single photon imaging through strongly scattering media

​​Non-invasive optical imaging through opaque and multi-scattering media remains highly desirable across many application domains. The random scattering and diffusion of light in such media inflict exponential decay and aberration, prohibiting diffraction-limited imaging. By non-interferometric few picoseconds optical gating of backscattered photons, we demonstrate single photon sensitive non-invasive 3D imaging of targets occluded by strongly scattering media with optical thicknesses reaching 9.5l_s (19l_s round trip). It achieves diffraction-limited imaging of a target placed 130 cm away through the opaque media, with millimeter lateral and depth resolution while requiring only one photon detection out of 50,000 probe pulses. Our single photon sensitive imaging technique does not require wavefront shaping nor computationally-intensive image reconstruction algorithms, promising practical solutions for …

S Maruca, P Rehain, YM Sua, S Zhu, Y Huang

Mode selective up-conversion detection with turbulence

We experimentally study a nonlinear optical approach to selective manipulation and detection of structured images mixed with turbulent noise. Unlike any existing adaptive-optics method by applying compensating modulation directly on the images, here we account for the turbulence indirectly, by modulating only the pump driving the nonlinear process but not the images themselves. This indirect approach eliminates any signal modulation loss or noise, while allowing more flexible and capable operations. Using specifically sum frequency generation in a lithium niobate crystal, we demonstrate selective upconversion of Laguerre-Gaussian spatial modes mixed with turbulent noise. The extinction reaches ~40 dB without turbulence, and maintains ~20 dB in the presence of strong turbulence. This technique could find utilities in classical and quantum communications, compressive imaging, pattern recognition, and so …

H Zhang, S Kumar, YP Huang

Super-resolution optical classifier with high photon efficiency

We propose and demonstrate a photon-efficient optical classifier to overcome the Rayleigh limit in spatial resolution. It utilizes mode-selective sum-frequency generation and single-pixel photon detection to resolve closely spaced incoherent sources based on photon counting statistics. Super-resolving and photon efficient, this technique can find applications in microscopy, light detection and ranging, and astrophysics.

H Zhang, S Kumar, YP Huang

Robust and efficient single-pixel image classification with nonlinear optics

We present a hybrid image classifier by feature-sensitive image upconversion, single pixel photodetection, and deep learning, aiming at fast processing of high-resolution images. It uses partial Fourier transform to extract the images’ signature features in both the original and Fourier domains, thereby significantly increasing the classification accuracy and robustness. Tested on the Modified National Institute of Standards and Technology handwritten digit images and verified by simulation, it boosts accuracy from 81.25% (by Fourier-domain processing) to 99.23%, and achieves 83% accuracy for highly contaminated images whose signal-to-noise ratio is only −17dB. Our approach could prove useful for fast lidar data processing, high-resolution image recognition, occluded target identification, and atmosphere monitoring.

S Kumar, T Bu, H Zhang, I Huang, Y Huang

Quantum Airy photons

With exotic propagation properties, optical Airy beams have been well studied for innovative applications in communications, biomedical imaging, micromachining, and so on. Here we extend those studies to the quantum domain, creating quantum correlated photons in finite-energy Airy transverse modes via spontaneous parametric down conversion and subsequential spatial light modulation. Through two-photon coincidence measurements, we verify their Airy spatial wavefunctions, propagation along a parabolic trajectory, and that the spatial modulation does not introduce any observable degradation of quantum correlation between the photons. These results suggest the feasibility of using spatially structured photons for practically advantageous quantum applications.

S Maruca, S Kumar, YM Sua, JY Chen, A Shahverdi, YP Huang

Single photon imaging and sensing of highly obscured objects around the corner

Non-line-of-sight (NLOS) optical imaging and sensing of objects imply new capabilities valuable to autonomous technology, machine vision, and other applications, in which case very few informative photons are buried in strong background counts. Here, we introduce a new approach to NLOS imaging and sensing using the picosecond-gated single photon detection generated by nonlinear frequency conversion. With exceptional signal isolation, this approach can reliably achieve imaging and position retrieval of obscured objects around the corner, in which case only 4 × 10^−3 photons are needed to be detected per pulse for each pixel with high temporal resolution. Furthermore, the vibration frequencies of different objects can be resolved by analyzing the photon number fluctuation received within a ten-picosecond window, allowing NLOS acoustic sensing. Our results highlight the prospect of photon efficient …

S Zhu, YM Sua, P Rehain, YP Huang

Quantum 3D imaging through multiscattering media of 10 optical depth

High resolution three dimensional (3D) optical imaging in the turbid underwater scenarios over extended length remains an outstanding challenge, primarily impeded by the absorption and scattering in turbid water, which result in substantial signal attenuation over short propagation distances. Overcoming water absorption by using optimum illumination wavelengths (480- 600 nm) of the visible spectrum, however, still requires one to address the strong scattering effects. To address the above challenge, we introduce a novel 3D imaging modality based on quantum parametric mode sorting (QPMS). It is a nascent quantum measurement technique that utilizes mode-selective quantum frequency conversion (QFC) in a χ2 nonlinear waveguide to up convert signal photons in a single spatiotemporal mode efficiently. Undesirable photons in other modes, even if they spectrally and temporally overlap with the signal, are …

YM Sua, S Zhu, P Rehain, D Tafone, B Muthuswamy, J Ramanathan, ...

Near-infrared 3D imaging with upconversion detection

We demonstrate a photon-sensitive, three-dimensional (3D) camera by active near-infrared illumination and fast time-of-flight gating. It uses picosecond pump pulses to selectively upconvert the backscattered photons according to their spatiotemporal modes via sum-frequency generation in a χ^2 nonlinear crystal, which are then detected by an electron-multiplying CCD with photon sensitive detection. As such, it achieves sub-millimeter depth resolution, exceptional noise suppression, and high detection sensitivity. Our results show that it can accurately reconstruct the surface profiles of occluded targets placed behind highly scattering and lossy obscurants of 14 optical depth (round trip), using only milliwatt illumination power. This technique may find applications in biomedical imaging, environmental monitoring, and wide-field light detection and ranging.

H Zhang, S Kumar, YM Sua, S Zhu, YP Huang

Single-Pixel Image Classification via Nonlinear Optics and Deep Neural Network

We propose and experimentally demonstrate a hybrid system which utilizes a nonlinear mode-selective optical method to extract the features with single-pixel detection and subsequently recognize the high-resolution images from a deep neural network.

S Kumar, T Bu, H Zhang, I Huang, YP Huang

Programmable Spatiotemporal Quantum Parametric Mode Sorter

We experimentally demonstrate a programmable parametric mode sorter of high-dimensional signals in a composite spatiotemporal Hilbert space through mode-selective quantum frequency up-conversion. As a concrete example and with quantum communication applications in mind, we consider the Laguerre-Gaussian and Hermite-Gaussian modes as the spatial and temporal state basis for the signals, respectively. By modulating the spatiotemporal profiles of the up-conversion pump, we demonstrate the faithful selection of signal photons in those modes and their superposition modes. Our results show an improvement in the quantum mode-sorting performance by coupling the up-converted light into a single-mode fiber and/or operating the up-conversion at the edge of phase matching. Optimizing pump temporal profiles allows us to achieve more than 12-dB extinction for mutually unbiased basis (MUB) sets of …

M Garikapati, S Kumar, H Zhang, YM Sua, YP Huang

Yu-Ping,“Huang,“Generation of Quantum Airy Photons,”

S Kumar, S Maruca, YM Sua

Single-pixel image reconstruction using coherent nonlinear optics

We propose and experimentally demonstrate a novel, to the best of our knowledge, hybrid optoelectronic system that utilizes mode-selective frequency upconversion, single-pixel detection, and a deep neural network to achieve the reliable reconstruction of two-dimensional (2D) images from a noise-contaminated database of handwritten digits. Our system is designed to maximize the multi-scale structural similarity index measure (MS-SSIM) and minimize the mean absolute error (MAE) during the training process. Through extensive evaluation, we have observed that the reconstructed images exhibit high-quality results, with a peak signal-to-noise ratio (PSNR) reaching approximately 20 dB and a structural similarity index measure (SSIM) of around 0.85. These impressive metrics demonstrate the effectiveness and fidelity of our image reconstruction technique. The versatility of our approach allows its application in …

M Thomas, S Kumar, YP Huang

Mode-selective image upconversion through turbulence

We experimentally and numerically show the selective image up-conversion of Laguerre-Gaussian modes through turbulent noise, with potential applications in areas of image recognition and free-space optical communications.

H Zhang, S Kumar, YP Huang

Laser Science, JW3A. 46 1 2019

Devices and methods for giant single-photon nonlinearities

A periodically poled microring resonator structure, a method for fabrication of the periodically poled microring resonator structure, and a method to achieve giant single-photon nonlinearity are disclosed. The strong single-photon nonlinearity in the microring resonator structure is achieved through its optimized design and fabrication procedures.

Y Huang, J Chen

US Patent 11,754,908 2023

Compressive Non-Line-of-Sight Imaging with Deep Learning

In non-line-of-sight (NLOS) imaging, the spatial information of hidden targets is reconstructed from the time-of-light (TOF) of the multiple bounced signal photons. The need for NLOS imagers to perform extensive scanning in the transverse spatial dimensions constrains the imaging speed and reconstruction quality while limiting their applications on static scenes. Utilizing a photon TOF histogram with picosecond temporal resolution, we develop compressive non-line-of-sight imaging enabled by deep learning. Two-dimensional images (32× 32 pixels) of the NLOS targets can be reconstructed with superior reconstruction quality via a convolutional neural network (CNN), using significantly downscaled data (8× 8 scanning points) at a downsampling ratio of 6.25% compared to the traditional methods. The CNN is end-to-end trained purely using simulated data but robust for image reconstruction with experiment data …

S Zhu, YM Sua, T Bu, YP Huang

Physical Review Applied 19 (3), 034090 2023

Devices and methods for giant single-photon nonlinearities

A periodically poled microring resonator structure, a method for fabrication of the periodically poled microring resonator structure, and a method to achieve giant single-photon nonlinearity are disclosed. The strong single-photon nonlinearity in the microring resonator structure is achieved through its optimized design and fabrication procedures.

Y Huang, J Chen

US Patent App. 17/468,182 2022

Single photon imaging and sensing of obscured objects around the corner

S Zhu, YM Sua, P Rehain, YP Huang

arXiv preprint arXiv:2106.08210 2021

Mode-Selective Image Upconversion Through Turbulence

We experimentally demonstrate a frequency upconversion approach to selective detection of structured images passing through turbulent media, where the turbulence is indirectly compensated by modulating the upconversion pump.

S Kumar, H Zhang, YP Huang

Conference on Coherence and Quantum Optics, W6A. 20 2019

Noise-tolerant 3D Imaging

We demonstrate noise-tolerant 3D imaging with 8 dB noise rejection beyond the theoretical limit of linear-optical matched filters. We perform the imaging from only 0.0006 detected signal photons per pulse despite being swamped by 50-folds stronger background noise.

P Rehain, YM Sua, S Zhu, I Dickson, B Muthuswamy, J Ramanathan, ...

CLEO: Science and Innovations, JTh5A. 10 2019

Interaction-free All-optical Modulation on Chip

We report the observation of quantum Zeno blockade on chip, where a lightwave is modulated by another in a distinct “interaction-free” manner. For quantum applications, we also verify its operations on single photons.

JY Chen, YM Sua, ZT Zhao, M Li, YP Huang

Frontiers in Optics, JW4A. 12 2017

Interaction-free All-optical Switches for Quantum Applications

We present a realization of all-optical switching in whispering-gallery-mode microcavities. Operating without the control and probe light beams overlapping in the cavity (in the asymptotic limit), such switches are ideal for use with quantum signals.

YP Huang, AS Kowligy, YZ Sun, DV Strekalov, P Kumar

Frontiers in Optics, FM4B. 2 2014

All-optical quantum switching

We will present progress in ultrafast all-optical quantum switching. c (3)-based devices can route entangled photons without disturbing their quantum state, whereas c (2)-based devices can, in principle, lead to dissipation-free quantum-optical Fredkin gates.

P Kumar, YP Huang

International Conference on Fibre Optics and Photonics, W1C. 1 2012

Ultrafast switching of photonic entanglement

We present our recent development of fiber-optic technology for all-optical switching and routing of entangled photons at high speeds, with minimal loss and added in-band noise, and-most importantly-without disturbing the photons' quantum state.

NN Oza, YP Huang, P Kumar

IEEE Photonics Conference 2012, 413-414 2012

Quantum information processing in the telecom waveband

We present recent progress in all-optical routing of entangled single photons at high speeds, with minimal loss and added in-band noise, and-most importantly-without disturbing the photons' quantum state.

P Kumar, YP Huang, JB Altepeter, M Patel, NN Oza, MA Hall

OFC/NFOEC, 1-3 2012

Mixing light and matter waves: Principles and applications

The work of this dissertation is committed to theoretically explore rich physics involving quantum-mechanical mixing of light and matter waves, while specifically seeking applications in the fields of quantum interferometry, quantum information processing, and testing fundamental quantum mechanics. Towards this goal, the present research is guided by two lines. The first line is to study and manipulate collective behaviors of multi-atom systems at quantum-degenerate temperature, where the wave nature of atoms is maximized. Specifically, a variety of phase-coherent mixing processes of two macroscopic matter-waves, in the form of gaseous Bose-Einstein condensate (BEC), are investigated and engineered via (i) tuning atomic collisional interaction and/or inter-wave tunneling rate;(ii) mixing with optical waves of phase-locked lasers. By these means, a series of novel applications are proposed for generating highly …

Y Huang

Michigan State University 2009

Interaction-and measurement-free quantum information processing with single-atom and/or single-photon qubits

Interaction-free measurement (IFM) uses quantum interference to allow a single photon to detect a perfectly absorbing object without the photon interacting with the object directly. In high-efficiency IFM, the Quantum Zeno Effect is employed to increase the success probability from the original 50% to (Na)/N, where N is the number of cycles the photon makes through the device and a 1. In principle IFM protocols allow the hyperfine state of a single atom to become entangled with the polarization of a single photon. To date, attempts to employ this entanglement to create universal atom-atom quantum logic gates, such as CNOT gates, have not succeeded in achieving (Na)/N efficiency. In addition, they also require the detection of ancillary photons. At present, single-photon detection cannot be implemented experimentally with high efficiency. By making several key modications, we have developed a pair of …

M Moore, Y Huang

APS Division of Atomic, Molecular and Optical Physics Meeting Abstracts 38 … 2007

Measuring an unknown phase with quantum-limited precision using nonlinear beamsplitters

High precision phase measurement is currently a central goal of quantum interferometry. In general, the precision is described by the phase estimation uncertainty δθ, which is characterized by two scaling behaviors, shot-noise limited with δθ∼ 1/√ N and Heisenberg limited with δθ∼ 1/N (N the total particle number). According to Bayesian analysis, Heisenberg limited preciosion for θ= 0 can be achieved in a Mach-Zehnder interferometer with (| N-1, N+ 1>+| N+ 1, N-1>)/√ 2 as input state based and a single measurement or| N, N> input based on multiple measurements. As θ deviates from zero, both schemes degrade rapidly to worse than shot-noise-limited precision. In contrast, a Quantum Fourier Transform (QFT) based interferometer can measure an arbitrary θ at Heisenberg limited precision, but requires a quantum computer. To extend the range of precisely measurable θ without a quantum computer, we …

Y Huang, M Moore

APS Division of Atomic, Molecular and Optical Physics Meeting Abstracts 38 … 2007