Abstract Precise manipulation of Bragg reflection in cholesteric liquid crystals (CLCs) is essential for advancing reconfigurable optics. However, existing photo-responsive material-doped CLC technologies that rely on single-wavelength photoisomerization encounter several challenges, including slow response times, limited tunability, inadequate spatial control, and instability caused by pitch variations due to diffusion. Here, we present a robust dual-wavelength photoisomerization method to simultaneously achieve trans -to- cis and cis -to- trans photoisomerization of chiral azobenzene-doped CLCs, which enables broadband, reversible, and spatially addressable control over the Bragg reflection spectrum. By employing counterpropagating laser beams at 405 nm and 532 nm, we precisely control the trans – cis isomerization dynamics of azobenzene chiral dopants, achieving spectral shifts exceeding 100 nm primarily through reversible modulation of the helical pitch of the CLCs. Furthermore, manipulating the intensity ratio and geometry of the excitation beams allows for tailored pitch gradients, reflection bandwidths, and central wavelengths with remarkable fidelity. Our approach enhances pitch boundaries and reduces molecular diffusion, facilitating the micrometer-scale patterning of optical textures, which surpasses traditional single-wavelength methods. Additionally, we present an innovative narrowband spectral filtering technique by sequentially transmitting light through pitch-selective CLC regions under circular polarization control. This reconfigurable manipulation strategy paves the way for developing programmable photonic systems, including adaptive optics, diffractive optics, and tunable displays.

Wavefront shaping is essential for optical imaging through aberrations, but conventional methods rely on physical modulators and iterative optimization, hindering real-time applications in dynamic environments like turbulence. Inspired by quantum nonlocal aberration cancellation, we propose a modulator-free, computational wavefront shaping technique. By leveraging classical correlated illumination and single-pixel detection, our method corrects aberrations via virtual phase modulation in the computational domain, eliminating physical spatial light modulators or array sensors. As validation, we demonstrate this approach in a distributed optical aperture synthesis imaging, where a phase-randomized laser array illuminates objects through turbulence. Despite unknown subsource phase mismatch and turbulent distortion, we reconstruct diffraction-limited images of a 3-meter standoff object, at the theoretical resolution limit of the synthetic aperture (0.157 millimeter experimentally; 97% of the 0.152-millimeter limit). This work transforms traditionally intractable hardware challenges into computationally solvable problems, enabling turbulence-resilient standoff imaging without adaptive optics.

Adaptive Optics Stimulated Raman Scattering Microscopy for Topical Product Pharmacokinetic Imaging

Triple crystal high resolution x-ray diffraction setup based on adaptive bending X-ray optics (ABXO) elements functioning in fully resonant mode

PurposeTo characterize red blood cell (RBC) distribution and associated changes in cell size at capillary junctions in the human neural retina.MethodsCell-resolved blood flow across 60 capillary junctions in the retina of 6 healthy human subjects was measured, using flood-illumination adaptive optics at 200 to 400 fps. Several empirical RBC partitioning models, including a widely used model developed by Pries et al., were compared for predictive accuracy.ResultsWe provide updated Pries model coefficients to suit human retinal capillaries. We also propose a simpler linear model that predicts RBC flow distribution based solely on the share of blood flow received by a branch, without reference to the main vessel. Cell size analysis revealed that the average RBC volume in branch vessels was 5.5% lower than in the main vessel (P < 0.05). The reduction in cell volume accompanied a 2.3 µm increase in inter-cell spacing (P < 10−4) and a 3.0% decrease in hematocrit (P < 10−4). These findings support the hypothesis of a net transfer of water from RBCs to plasma as they pass through narrower capillary branches, with potential reabsorption by the time cells enter wider collecting capillaries.ConclusionsThis study provides the first noninvasive in vivo characterization of RBC partitioning behavior at capillary junctions in the living human retina. The subtle fluid exchange between cells and plasma may play a role in optimizing oxygen delivery to support immediate metabolic needs.

Background: INPP5E-related retinopathy (INPP5E-RR) is a rare genetic disorder caused by biallelic pathogenic variants in the INPP5E gene, which encodes an enzyme critical for phosphoinositide signaling. While early-onset rod–cone dystrophy is a hallmark feature, detailed longitudinal data on the phenotype are scarce. This study aims to report a 6-year longitudinal assessment of retinal structure and function in a case of non-syndromic INPP5E-RR. Methods: A 42-year-old female proband with compound heterozygous pathogenic missense variants in INPP5E (p.Arg486Cys and p.Arg378Cys) was monitored from 2019 to 2025. She underwent serial comprehensive ophthalmologic evaluations, including optical coherence tomography (OCT), fundus autofluorescence, adaptive optics transscleral flood illumination, full-field 30Hz flicker electroretinography (ERG), and macular frequency-doubling technology perimetry. Results: Over the 6-year follow-up, OCT imaging revealed a progressive decline in the ellipsoid zone (EZ) width, from 1220 µm to 720 µm (~80 µm/year), and in the inner nuclear layer (INL) thickness. The central outer nuclear layer (ONL) thickness was preserved, but intraretinal cysts developed. Functional testing revealed a progressive decline in cone flicker ERG amplitudes, while visual acuity and macular perimetry remained stable. Conclusions: In this genotypically confirmed case, the longitudinal data identify EZ width, INL thickness, and cone flicker ERG as robust biomarkers of disease progression in INPP5E-RR. These parameters are ideal candidates for monitoring therapeutic outcomes in future clinical trials.

The size of the Starship we see launching us into the future is immense, to Mear mortals. That is why you see these circles on the floors. Each represents a Starship cargo hold of Eight meters by 8 meters diameter, with some room in the cone. No more origami, because you can spread out your assembly to many Starships. Construction EVA astronauts will soon be seen putting together ever larger chunks, like telescopes. Habitats, Sports arenae.My pet project is a telescope the size of the Giant Magellan. Leaner, no adaptive optics, space hardened mount, Starlink communications. It remains a massive observatory, requiring sensors for not just mechanical well-being, and aiming, but astronomical instrumentation to deal with 25.2 meters of photon bucket. The instrumentation used in Chile will need to be hardened for launch and matched for interferometry. Molded in parallel, 7 mirrors could be ready soon after Starship certifies for launch of humans. And Construction Astronauts will be ready about then.Which ECS divisions will go into our observatory? Probably all, certainly all will be included in the experimental sphere. The point is, space and mass, while still required to be tracked, but we have plenty and we can launch a hundred and fifty tons per launch, per day. For many loads, paying just for the fuel and a rental fee.Would you like to go along? Your current projects will all fit into one launch, finish them, build bigger for the next launch. Space suits all around. Figure 1

Solar ground-layer adaptive optics (GLAO) is widely recognized as a key technology for achieving high-resolution, wide-field imaging in ground-based solar telescopes. However, the accuracy differences among various wavefront sensing methods in solar GLAO remain unclear. In this study, Monte Carlo simulations and indoor GLAO experiments were conducted to perform, for the first time, a comparative analysis of two representative wavefront sensing methods: multi-direction averaging (MD-A) and wide-field correlation (WF-C). The results demonstrate that WF-C consistently achieves higher detection accuracy than MD-A, although the differences between the two methods are small. With an increasing field of view (FoV), the detection accuracy of MD-A improves but remains lower than that of WF-C. In terms of correction performance, significant improvements in central FoV imaging were achieved using WF-C within narrow-to-moderate FoVs, whereas in wide and ultra-wide FoVs, MD-A produced more uniform image quality enhancements. Using the 1 m New Vacuum Solar Telescope (NVST) GLAO system as an example, MD-A is better suited to wide and future ultra-wide field imaging (over 80″), whereas WF-C is more appropriate for high-precision wavefront sensing within narrow to moderate fields (20″–60″). These findings provide both theoretical guidance and practical insights for the optimization of GLAO systems and wavefront sensing strategies in 1-meter-class wide-field solar telescopes.

This study addresses the inherent limitations of conventional metalenses, specifically their rigid substrates and static focal lengths, which constrain their utility in dynamic and conformal optical systems. We present the development of a flexible, achromatic metalens engineered for operation within the near-infrared spectrum (870–1080 nm). This innovative design incorporates a stretchable polydimethylsiloxane substrate embedded with a silicon–MgF 2 cross-square nanoblock. The resultant metalens exhibits exceptional focal length tunability, achieving a remarkable 206% variation through mechanical stretching ranging from 0% to 30%. Crucially, it sustains polarization-insensitive focusing with stable efficiencies ranging from 50% to 64% across bandwidth and stretching ratios. Through the integration of an antireflective material, the application of nanostructure property optimization techniques, and the utilization of a hybrid cross-square nanoblocks, the metalens demonstrates minimal chromatic aberration and maintains stable focusing efficiency despite mechanical deformation. Finite-difference time-domain (FDTD) simulations rigorously validate its performances across all states. This advancement has significant implications for adaptive optics in biomedical imaging, telecommunications, and augmented reality, thereby facilitating the development of versatile, high-performance photonic devices for flexible and wearable technologies.

High-contrast imaging relies on advanced coronagraphs and adaptive optics (AO) to attenuate the starlight. However, residual aberrations, especially non-common path aberrations between the AO channel and the coronagraph channel, limit the instrument performance. While post-processing techniques such as spectral or angular differential imaging (ADI) can partially address those issues, they suffer from self-subtraction and inefficiencies at small angular separations or when observations are conducted far from transit. We previously demonstrated the on-sky performance of coherent differential imaging (CDI), which offers a promising alternative. It allows for isolating coherent starlight residuals through speckle modulation, which can then be subtracted from the raw images during post-processing. This work aims to validate a CDI method on real science targets using VLT/SPHERE, demonstrating its effectiveness in imaging almost face-on circumstellar disks, which are typically challenging to retrieve with ADI. We temporally modulated the speckle field in VLT/SPHERE images, applying small phase offsets on the AO deformable mirror while observing stars surrounded by circumstellar material: HR 4796A, CPD-36 6759, HD 169142, and HD 163296. We hence separated the astrophysical scene from the stellar speckle field, whose lights are mutually incoherent. Combining a dozen of data frames and reference coronagraph point spread functions through a Karhunen–Loève image projection framework, we recover the circumstellar disks without the artifacts that are usually introduced by common post-processing algorithms (e.g., self-subtraction). The CDI method therefore represents a promising strategy for calibrating the effect of static and quasi-static aberrations in future direct imaging surveys. Indeed, it is efficient, does not require frequent telescope slewing, and does not introduce image artifacts to first order.

GRAVITY+ improves by orders of magnitude the sensitivity, sky-coverage, and contrast of the Very Large Telescope Interferometer (VLTI). A central part of this project is the development of Gravity Plus Adaptive Optics (GPAO), a dedicated high-order and laser-guide star adaptive optics (AO) system for VLTI. GPAO consists of four state-of-the-art AO systems that equip all 8m class Unit Telescopes (UTs) for the wavefront correction of the VLTI instruments. It offers both visible and infrared natural guide star (NGS) and laser guide star (LGS) operations. The paper presents the design, operations, and performances of GPAO. We illustrate the improvement brought by GPAO with interferometric observations obtained during the commissioning of the NGS mode at the end of 2024. These science results include the first optical interferometry observations of a redshift z∼4 quasar, the spectroscopy of a cool brown-dwarf with magnitude K∼ 21.0, the first observations of a Class I young star with GRAVITY, and the first sub-micro arcsecond differential astrometry in the optical. Together with the entire GRAVITY+ project, the implementation of GPAO is a true paradigm shift for observing the optical Universe at very high angular resolution.

Precise adjustment of the three-dimensional position of the deformable mirror in adaptive optics assisted microscopy

Abstract Substellar companions such as exoplanets and brown dwarfs exhibit changes in brightness arising from top-of-atmosphere inhomogeneities, providing insights into their atmospheric structure and dynamics. This variability can be measured in the light curves of high-contrast companions from the ground by combining differential spectrophotometric monitoring techniques with high-contrast imaging. However, ground-based observations are sensitive to the effects of turbulence in Earth’s atmosphere, and while adaptive optics (AO) systems and bespoke data processing techniques help to mitigate these, residual systematics can limit photometric precision. Here, we inject artificial companions to data obtained with an AO system and a vector Apodizing Phase Plate coronagraph to test the level to which telluric and other systematics contaminate such light curves, and thus how well their known variability signals can be recovered. We find that varying companions are distinguishable from non-varying companions, but that variability amplitudes and periods cannot be accurately recovered when observations cover only a small number of periods. Residual systematics remain above the photon noise in the light curves but have not yet reached a noise floor. We also simulate observations to assess how specific systematic sources, such as non-common path aberrations and AO residuals, can impact aperture photometry as a companion moves through pupil-stabilised data. We show that only the lowest-order aberrations are likely to affect flux measurements, but that thermal background noise is the dominant source of scatter in raw companion photometry. Predictive control and focal-plane wavefront sensing techniques will help to further reduce systematics in data of this type.

Single scan adaptive optics – optical coherence tomography angiography for absolute three-dimensional retinal blood flow mapping

Enhanced S-cone syndrome (ESCS) is a rare inherited retinal dystrophy characterized by a marked increase in S-cone cell function and simultaneous loss of rod photoreceptors. It typically presents in childhood with night blindness (nyctalopia) and may be misdiagnosed as retinitis pigmentosa or congenital stationary night blindness. The disease follows an autosomal recessive inheritance pattern and is caused by mutations in the NR2E3 gene, a nuclear receptor involved in retinal photoreceptor differentiation. These mutations disrupt normal development, leading to a retina dominated by S-cones and lacking functional rods. Clinically, ESCS progresses through distinct stages, starting with peripheral photoreceptor loss, followed by macular schisis and decrease in visual acuity, and finally retinal thinning with persistent vision impairment. Optical coherence tomography (OCT) and adaptive optics imaging reveal structural disruptions, including foveoschisis and abnormal layering. Electroretinography (ERG) shows absent rod responses and increased S-cone activity. Fundus findings include pigment clumping, yellow-white dots, macular changes, and, in some cases, subretinal fibrosis. Despite abnormal cone distribution, color vision can remain relatively intact. Currently, there is no cure for ESCS. Management focuses on treating complications like cystoid macular edema with carbonic anhydrase inhibitors, and addressing choroidal neovascularization with anti-VEGF agents. Gene therapy, particularly with CRISPR-Cas9 and AAV-based vectors, is under investigation. NR2E3 mutations are also linked to related disorders such as Goldmann-Favre syndrome, clumped pigmentary retinal degeneration, and retinitis pigmentosa, reflecting a spectrum of phenotypes. These overlapping conditions highlight the gene’s critical role in retinal development and degeneration. ESCS continues to be a valuable model for studying photoreceptor biology and exploring emerging genetic therapies.

Retinal blood flow in eyes with primary open-angle glaucoma using a new Adaptive Optics Laser Doppler Velocimeter device.

Prognostic value of the wall-to-lumen ratio of retinal arteries in patients with end-stage chronic kidney disease.

Adaptive optics (AO) ophthalmoscopes allow high-resolution imaging of retinal structure and function at the cellular level. Due to their high magnification and small field-of-view (FOV), these systems require precise fixation and light delivery to control the retinal region being imaged and stimulated. We present a high-efficiency fixation and stimulus channel for AO ophthalmoscopy, offering an extended working distance, wide steering range, and broad dioptric correction. For stimulation, the channel delivers intense, near-monochromatic light flashes across much of the visible spectrum. Our design uses all stock components, except for a 3D-printed conic mount and a few machined parts. We balance key system trade-offs and demonstrate design performance through several AO optical coherence tomography (AO-OCT) structural and functional imaging examples. Although originally developed for the Indiana AO-OCT system, these design principles can be readily applied to other AO ophthalmoscopic platforms.

Three-dimensional structured illumination microscopy (3D-SIM) doubles the resolution of fluorescence imaging in all directions and enables optical sectioning with increased image contrast. However, 3D-SIM has not been widely applied to imaging deep in thick tissues due to its sensitivity to sample-induced aberrations, making the method difficult to apply beyond 10 µm in depth. Furthermore, 3D-SIM has not been available in an upright configuration, limiting its use for live imaging while manipulating the specimen, for example, with electrophysiology. Here, we have overcome these barriers by developing a novel upright 3D-SIM system (termed Deep3DSIM) that incorporates adaptive optics for aberration correction and remote focusing, reducing artefacts, improving contrast, restoring resolution, and eliminating the need to move the specimen or the objective lens in volume imaging. These advantages are equally applicable to inverted 3D-SIM systems. We demonstrate high-quality 3D-SIM imaging in various samples, including imaging more than 130 µm into the Drosophila brain.

Reaching the high angular resolution and contrast level desired for exoplanetary science requires us to equip large telescopes with extreme adaptive optics (XAO) systems to compensate for the effect of the atmospheric turbulence at a very fast rate. This calls for the development of ultra-sensitive wavefront sensors (WFSs), such as Fourier filtering wavefront sensors (FFWFSs), to be operated at low flux, as well as an increase in the XAO loop frame rate. These sensors, which constitute the baseline for current and future XAO systems, exhibit such a high sensitivity at the expense of a non-linear behaviour that must be properly calibrated and compensated for to deliver the required performance. We aim to validate on-sky a recently proposed method that associates the FFWFS with a focal plane detector -- the gain scheduling camera (GSC) -- to estimate in real time the first-order terms of the sensor non-linearities, known as modal optical gains. We implemented a GSC on the adaptive-optics (AO) bench PAPYRUS to be associated with the existing pyramid wavefront sensor (PWFS). We compared experimental results to expected results obtained with a high-fidelity numerical twin of the AO system. We validated experimentally the method both in laboratory and on-sky. We demonstrated the capability of the GSC to accurately estimate the optical gains of the PWFS at 100 Hz, corresponding to the current limit in speed imposed by PAPYRUS hardware, but it could be applied at higher frequencies to enable frame-by-frame optical gains tracking. The presented results exhibit good agreement on the optical gains estimation with respect to numerical simulations reproducing the experimental conditions tested. Our experimental results validate the strategy of coupling a FFWFS with a focal-plane camera to master the non-linearities of the sensor. This demonstrates its attractiveness for future XAO application.