Non-contact elasticity contrast imaging using photon counting.

Significance: Tissues' biomechanical properties, such as elasticity, are related to tissue health. Optical coherence elastography produces images of tissues based on their elasticity, but its performance is constrained by the laser power used, working distance, and excitation methods.

Aim: We develop a new method to reconstruct the elasticity contrast image over a long working distance, with only low-intensity illumination, and by non-contact acoustic wave excitation.

Single-photon vibrometry.

We propose and demonstrate a single-photon sensitive technique for optical vibrometry. It uses high speed photon counting to sample the modulated backscattering from a vibrating target. Designed for remote vibration sensing with ultralow photon flux, we show that this technique can detect small displacements down to 110 nm and resolve vibration frequencies from DC up to several kilohertz, with ≤0.

Single-point material recognition by quantum parametric mode sorting and photon counting.

We explore an active illumination approach to remote material recognition, based on quantum parametric mode sorting and single-photon detection. By measuring a photon's time of flight at picosecond resolution, 97.8% recognition is demonstrated by illuminating only a single point on the materials.

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.

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.

Programmable quantum random number generator without postprocessing.

We demonstrate a viable source of unbiased quantum random numbers whose statistical properties can be arbitrarily programmed without the need for any postprocessing such as randomness distillation or distribution transformation. It is based on measuring the arrival time of single photons in shaped temporal modes that are tailored with an electro-optical modulator. We show that quantum random numbers can be created directly in customized probability distributions and pass all randomness tests of the NIST and Dieharder test suites without any randomness extraction.