Digital optical phase conjugation (DOPC) is a new technique employed in wavefront shaping and for focusing light through or within scattering media such as biological tissues. DOPC particularly attractive it intrinsically achieves high fluence reflectivity comparison to nonlinear approaches. However, the slow refresh rate of liquid crystal spatial modulators limitations imposed by computer data transfer speeds have thus far made difficult achieve playback latency shorter than ~200 ms and,...

Abstract Shack–Hartmann wavefront sensors measure the local slopes of an incoming based on displacement focal spots created by a lenslet array, serving as key components for adaptive optics astronomical and biomedical imaging. Traditionally, challenges in increasing density curvature have limited use such characterizing slowly varying structures. Here, we develop metasurface-enhanced sensor (meta SHWFS) to break this limit, considering interplay between parameters performance SHWFS. We...

Using ultrasound-guided optical wavefront shaping, the authors show enhanced optogenetic control in thick acute brain slices.

Light scattering in biological tissue significantly limits the accessible depth for localized optical interrogation and deep-tissue imaging. This challenge can be overcome by exploiting time-reversal property of phase conjugation (OPC) to reverse multiple events or suppress turbidity. However, living tissue, scatterers are highly movable movement disrupt symmetry when there is a latency OPC playback. In this paper, we show that motion-induced degradation turbidity-suppression effect through...

Optical phase conjugation (OPC) has enabled many optical applications such as aberration correction and image transmission through fiber.In recent years, implementation of digital (DOPC) opened up the possibility its use in biomedical optics (e.g.deep-tissue focusing) due to ability provide greater-than-unity OPC reflectivity (the power ratio conjugated beam input system) flexibility accommodate additional wavefront manipulations.However, requirement for precise (pixel-topixel matching)...

Abstract Focusing light inside scattering media in a freely addressable fashion is challenging, as the wavefront of scattered highly disordered. Recently developed ultrasound-guided shaping methods are addressing this challenge, albeit with relatively low modulation efficiency and resolution limitations. In paper, we present new technique, time-reversed ultrasound microbubble encoded (TRUME) optical focusing, which can focus improved sub-ultrasound wavelength resolution. This method...

Abstract The capability of focus control has been central to optical technologies that require both high temporal and spatial resolutions. However, existing varifocal lens schemes are commonly limited the response time on microsecond timescale share fundamental trade-off between tuning power. Here, we propose an ultrafast holographic focusing method enabled by translating speed a fast 1D beam scanner into complex wavefront modulation relatively slow 2D light modulator. Using pair digital...

Here, we quantitatively assess the effect of astigmatism on visual functions in eyes with three different commercial multifocal intraocular lenses (IOLs) using a customized finite eye model. Our proposed model implements full wave analysis whole structure diffractive IOLs under polychromatic conditions. The evaluates energy efficiency each focus at varying degrees corneal light-in-the-bucket metrics for bifocal (Restor), extended depth-of-focus (Symfony), and trifocal (POD-F). Better...

Abstract Interferometry often serves as an essential building block of wavefront shaping systems to obtain optimal solutions. In this tutorial, we provide a Monte Carlo simulation tool calculate the accuracy interferometric measurement and its impact on in context focusing through disordered media. particular, have focused evaluating fidelity under influence shot noise with practical considerations operation digital image sensors, including read-out dark current noises, digitization finite...

The Time-Reversed Ultrasound-Encoded (TRUE) light technique enables noninvasive focusing deep inside scattering media. However, the time-reversal procedure usually has a low signal-to-noise ratio because intensity of ultrasound-encoded is intrinsically low. Consequently, contrast and resolution TRUE focus far from ideal, especially in backscattering geometry, which more practical many biomedical applications. To improve focus, we developed an iterative (iTRUE) that employs itself as signal...

Novel techniques in the field of wavefront shaping have enabled light to be focused deep inside or through scattering media such as biological tissue. However, most these demonstrations been limited thin, static samples since are very sensitive changes arrangement scatterers within. As interest get thicker, influence dynamic nature sample becomes even more pronounced and window time which solutions remain valid shrinks further. In this paper, we examine scales upon decorrelation happens...

Abstract To extend the imaging depth of high-resolution optical microscopy, various gating operations—confocal, coherence, and polarization gating—have been devised to filter out multiply scattered wave. However, is still limited by wave that bypasses existing operations. Here, we present a space method, whose mechanism independent methods yet effective enough complement them. Specifically, reconstruct an image only using ballistic acousto-optically modulated at object plane. The suppresses...

Isotropic optical focusing - the of light with axial confinement that matches its lateral confinement, is important for a broad range applications. Conventionally, such achieved by overlapping focused beams from pair opposite-facing microscope objective lenses. However exacting requirements alignment lenses and method's relative intolerance to sample turbidity have significantly limited utility. In this paper, we present an phase conjugation (OPC)-assisted isotropic method can address both...

The time-reversed ultrasonically encoded (TRUE) optical focusing technique is a method that capable of light deep within scattering medium. This theoretical study aims to explore the depth limits TRUE for biological tissues in context two primary constraints - safety limit incident fluence and limited TRUE's recording time (assumed be 1 ms), as dynamic scatterer movements living sample can break time-reversal symmetry. Our numerical simulation indicates has potential render an focus with...

Variable light focusing is the ability to flexibly select focal distance of a lens. This feature presents technical challenges, but significant for optical interrogation three-dimensional objects. Numerous lens designs have been proposed provide flexible focusing, including zoom, fluid and liquid-crystal lenses. Although these lenses are useful macroscale applications, they limited utility in micron-scale applications due restricted modulation range exacting requirements fabrication control....

We demonstrate experimentally that optical phase conjugation can be used to focus light through strongly scattering media even when far less than a photon per degree of freedom is detected. found the best achievable intensity contrast equal total number detected photons, as long resolution system high enough. Our results budget extremely low, such in high-speed focusing dynamic or imaging deep inside tissue.

Fourier phase retrieval is a classical problem of restoring signal only from the measured magnitude its transform. Although Fienup-type algorithms, which use prior knowledge in both spatial and domains, have been widely used practice, they can often stall local minima. Convex relaxation methods such as PhaseLift PhaseCut may offer performance guarantees, but these algorithms are usually computationally expensive for practical use. To address this problem, here we propose novel unsupervised...