Abstract Optical imaging is commonly performed with either a camera and wide-field illumination or single detector scanning collimated beam; unfortunately, these options do not exist at all wavelengths. Single-pixel offers an alternative that can be illumination, potentially enabling applications in which the detection technologies are immature. However, single-pixel currently suffers from low rates owing to its reliance on configurable spatial light modulators, generally limited 22 kHz...

Abstract Medical ultrasound and optoacoustic (photoacoustic) imaging commonly rely on the concepts of beam-forming tomography for image formation, enabled by piezoelectric array transducers whose element size is comparable to desired resolution. However, tomographic measurement acoustic signals becomes increasingly impractical resolutions beyond 100 µm due reduced efficiency elements upon miniaturization. For higher resolutions, a microscopy approach preferred, in which single focused...

We present a new type of self-imaging phenomenon: along curved trajectories. Unlike the Talbot effect, where occurs for periodic wave patterns propagating straight line, here field is generally not and self-imaged In paraxial regime, parabolic trajectory can ideally go on indefinitely. nonparaxial regime circular lasts as long beam bends. demonstrate this accelerating effect experimentally, discuss generalizations to higher dimensions.

The detection of ultrasound via optical resonators is conventionally performed by tuning a continuous-wave (CW) laser to the linear slope resonance and monitoring intensity modulation at resonator output. While offers advantage simplicity, its sensitivity often limited frequency noise CW laser. In this work, we develop an alternative technique that can significantly reduce measurement variations in phase, rather than intensity, our current implementation, which based on balanced Mach–Zehnder...

Silicon photonics leverages mature semiconductor technology to produce cost-effective and high-performance components for various applications in data centers, artificial intelligence, quantum computing. While the geometry of photonic integrated circuits can be characterized by existing means, their optimal accurate performance requires detailed characterization light propagating within them. Here we demonstrate first, our knowledge, direct visualization as it travels inside circuits. We...

In the optical detection of ultrasound, resonators with high Q-factors are often used to maximize sensitivity. However, increasing Q-factor a resonator may reduce linear range interrogation scheme, making it more susceptible strong external perturbations and incapable measuring acoustic signals. this Letter, passive-demodulation scheme for pulse interferometry was developed dynamic-range measurements. The passive based on an unbalanced Mach-Zehnder interferometer 90° hybrid, which...

In optical detection of ultrasound, resonators with high Q-factors are often used to maximize sensitivity. However, in order perform parallel interrogation, conventional interferometric techniques require an overlap between the spectra all resonators, which is difficult achieve Q-factor resonators. this paper, a new method developed for interrogation non-overlapping spectra. The based on phase-modulation scheme pulse interferometry (PM-PI) and requires only single photodetector sampling...

Silicon photonics is an emerging platform for acoustic sensing, offering exceptional miniaturization and sensitivity. While efforts have focused on silicon-based resonators, silicon nitride resonators can potentially achieve higher Q-factors, further enhancing In this work, a 30 µm microring resonator was fabricated coated with elastomer to optimize sensitivity signal fidelity. The characterized acoustically, its capability optoacoustic tomography demonstrated. An bandwidth of 120 MHz...

Abstract Objectives The mRNA-based COVID-19 vaccines are now employed globally and have shown high efficacy in preventing SARS-CoV-2 infection. However, less is known about the vaccine immune-suppressed individuals. This study sought to explore whether humoral immunity BNT162b2 altered RA patients treated with Janus kinase inhibitors by analysing their antibodies titre, neutralization activity B cell responses. Methods We collected plasma samples from 12 who were received two doses of...

Ultrasound detection via silicon waveguides relies on the ability of acoustic waves to modulate effective refractive index guided modes. However, low photo-elastic response and silica limits sensitivity conventional silicon-on-insulator sensors, in which core is surrounded by a cladding. In this paper, we demonstrate that ultrasound may be significantly enhanced replacing over-cladding with bisbenzocyclobutene (BCB)-a transparent polymer high coefficient. our experimental study, ultrasound,...

Silicon photonics holds promise for a new generation of ultrasound-detection technology, based on optical resonators, with unparalleled miniaturization levels, sensitivities, and bandwidths, creating possibilities minimally invasive medical devices. While existing fabrication technologies are capable producing dense resonator arrays whose resonance frequency is pressure sensitive, simultaneously monitoring the ultrasound-induced modulation numerous resonators has remained challenge....

Coherence-restored pulse interferometry (CRPI) is a recently developed method for optical detection of ultrasound that achieves shot-noise-limited sensitivity and high dynamic range. In principle, the wideband source employed in CRPI may enable interrogation multiple detectors by using wavelength multiplexing. However, noise-reduction scheme has not been shown to be compatible with operation. this work, we introduce new relies on free-space Fabry-Pérot filter noise reduction stretcher...

One of the main challenges in miniaturizing optoacoustic technology is low sensitivity sub-millimeter piezoelectric ultrasound transducers, which often insufficient for detecting weak signals. Optical detectors can achieve significantly higher sensitivities than their counterparts a given sensing area but generally lack acoustic focusing, essential many minimally invasive imaging configurations. In this work, we develop focused detector composed silicon-photonics optical resonator and...

We present an all-optical focused ultrasound transducer with a sub-millimeter aperture and demonstrate its capability for high-resolution imaging of tissue ex vivo. The is composed wideband silicon photonics detector miniature acoustic lens coated thin optically absorbing metallic layer used to produce laser-generated ultrasound. demonstrated device achieves axial resolution lateral resolutions 12 μm 60 μm, respectively, well below typical values achieved by conventional piezoelectric...

Abstract Optoacoustic tomography (OAT) is a hybrid imaging modality that combines optical excitation with ultrasound detection and enables high-resolution visualization of contrasts at tissue depths in which light completely diffused. Despite its promise numerous research clinical applications, OAT limited by the technological immaturity systems. It suffers from element count, narrow field view lack technology for spatial modulation acoustic signals. Here we report single-detector capable...

Ultrasound detection via optical resonators can achieve high levels of miniaturization and sensitivity as compared to piezoelectric detectors, but its scale-up from a single detector an array is highly challenging. While the use wideband sources may enable parallel interrogation multiple resonators, it comes at cost reduction in power, ultimately sensitivity, per channel. In this work we have developed new interferometric approach overcome signal loss by using high-power bursts that are...

A new ultrasound-detection technology is developed for ultrahigh-resolution optoacoustic tomography and experimentally demonstrated with bandwidths exceeding 200 MHz lateral resolutions beyond 20 μm. Our based on an optical resonator fabricated in a silicon-photonics platform, which coated by sensitivity-enhancing polymer, also eliminates the parasitic effect of surface acoustic waves. Further improvement sensitivity achieved low-noise interferometric setup, laser frequency noise...

Optoacoustic tomography (OAT) conventionally relies on curved detectors to maximize the sensitivity and lateral resolution. Here, we present an alternative paradigm OAT that creates a virtual detector array with high angular acceptance by using coded acoustic apertures flat piezoelectric detector. Using this approach, created 2D 1763 elements performed of complex 3D object approximate axial resolutions 150 μm 500 in detection geometry, demonstrating image quality comparable one achieved geometries.

In optical detection of ultrasound, resonators with high Q-factors are frequently used to maximize sensitivity. However, in order perform parallel interrogation, conventional interferometric techniques require an overlap between the resonator spectra, which is difficult achieve Q-factor resonators. this work, a new method developed for simultaneous interrogation non-overlapping spectra. The based on phase modulation scheme pulse interferometry (PM-PI) and requires only single photodetector...

We introduce a simple optical homodyne setup to perform time-domain Acousto-Optics imaging using photodiode. Our method introduces an SNR gain of over 4-fold compared system based on photomultiplier tube.

The ability to rapidly locate blood vessels in patients is important many clinical applications, e.g., catheterization procedures. Optical techniques, including visual inspection, generally suffer from a reduced performance at depths below 1 mm, while ultrasound and optoacoustic tomography are better suited typical depth on the scale of cm require an additional spacer between tissue transducer order image superficial structures focus plane. For this work, we developed hand-held probe,...

One of the main challenges in intravascular photoacoustic (IVPA) imaging is limited sensitivity and bandwidth miniaturized piezoelectric probes. Optical detectors ultrasound can drastically improve both these features, but often lack acoustic focusing. In this work, we developed a focused detector by integrating lens, made out glass, with silicon-photonics-based detector. A detection up to 80 MHz lateral resolution beyond 50 µm was demonstrated lens diameter 0.8 mm. Our device transparent...