Single Lens Research Articles

Analysis of the Problems of the Research and Modernization of Emission Units of Analytical Devices of Vacuum Electronics

In various electron-optical and ion-beam devices and vacuum electronics installations, emission elements and units are used to extract and form beams of charged particles. Their focusing properties significantly affect the quality parameters and technical characteristics of the analytical devices and technological installations in which they are used. Due to the specificity of the initial conditions during the formation of the beams of charged particles in the area of charged particle extraction, the methods of studying single and conventional immersion electron lenses are not suitable for the high quality theoretical and numerical studies of the properties of immersion objectives. In this paper, theoretical and numerical studies were conducted on the problems in analyzing the focusing parameters of charged particles in emission elements and units when solving problems of designing and upgrading devices and installations of vacuum electronics. As a result of the studies, a theoretical method for studying cathode lenses with a curved optical axis was developed and options for solving problems in correcting aberrations of emission elements and units were proposed.

Standoff Identification of Plastic Waste Using a Low-Cost Compact Laser-Induced Breakdown Spectroscopy (LIBS) Detection System.

We report the standoff/remote identification of post-consumer plastic waste by utilizing a low-cost and compact standoff laser-induced breakdown spectroscopy (ST-LIBS) detection system. A single plano-convex lens is used for collecting the optical emissions from the plasma at a standoff distance of 6.5 m. A compact non-gated Czerny-Turner charge-coupled device (CCD) spectrometer (CT-CCD) is utilized to analyze the optical response. The single lens and CT-CCD combination not only reduces the cost of the detection system by tenfold, but also decreases the collection system size and weight compared to heavy telescopic-based intensified CCD systems. All the samples investigated in this study were collected from a local recycling plant. All the measurements were performed with only a single laser shot which enables rapid identification while probing a large number of samples in real time. Furthermore, principal component analysis has shown excellent separation among the samples and an artificial neural network analysis has revealed that plastic waste can be identified within ∼10 ms only (testing time) with accuracies up to ∼99%. Finally, these results have the potential to build a compact and low-cost ST-LIBS detection system for the rapid identification of plastic waste for real-time waste management applications.

Finite Element Method Modelling for Extended Depth of Focus Acoustic Transducer

Abstract Extended depth of focus (DOF) with the high lateral resolution is the primary requirement of the transducer in scanning acoustic microscopy to generate high-resolution images of the 3-dimensional sample over a large depth. Traditionally, focused ultrasonic spherical transducers are used to tightly focus the acoustic waves generated from a piezoelectric material for a wide range of applications in industrial, medical, and other fields. Such transducers have a problem of narrow DOF which restricts the imaging range in depth. In the present work, we propose three different transducer designs such as single axicon, central flat axicon and double axicon, which enable the possibilities of high transverse resolution imaging over greater depths due to the significant increase in DOF. Finite element modeling (FEM) in COMSOL of a spherical, single axicon, central flat axicon, and double axicon transducer is systematically performed and compared in terms of transverse resolution, DOF, and acoustic pressure in the central lobe. In addition, the single axicon and double axicon transducer modeling are done for different apex angles. It is observed that the central flat axicon transducer allows customizable DOF and the double axicon transducer provides high lateral resolution and reduced pressure in the side lobes compared to a single axicon lens.

Field-grown tomato yield estimation using point cloud segmentation with 3D shaping and RGB pictures from a field robot and digital single lens reflex cameras

The aim of this study was to estimate field-grown tomato yield (weight) and quantity of tomatoes using a self-developed robot and digital single lens reflex (DSLR) camera pictures. The authors suggest a new approach to predicting tomato yield that is based on images taken in the field, 3D scanning, and shape. Field pictures were used for tomato segmentation to determine the ripeness of the crop. A convolution neural network (CNN) model using TensorFlow library was devised for the segmentation of tomato berries along with a small robot, which had a 59.3 % F1 score. To enhance the accurate tomato crop model and to estimate the yield later, point cloud imaging was applied using a Ciclops 3D scanner. The best fitting sphere model was generated using the 3D model. The most optimal model was the 3D model, which gave the best representation and provided the weight of the tomatoes with a relative error of 21.90 % and a standard deviation of 17.9665 %. The results indicate a consistent object-based classification of the tomato crop above the plant/row level with an accuracy of 55.33 %, which is better than in-row sampling (images taken by the robot). By comparing the measured and estimated yield, the average difference for DSLR camera images was more favorable at 3.42 kg.

Design of a Novel Microlens Array and Imaging System for Light Fields.

Light field cameras are unsuitable for further acquisition of high-quality images due to their small depth of field, insufficient spatial resolution, and poor imaging quality. To address these issues, we proposed a novel four-focal-square microlens and light field system. A square aspheric microlens array with four orthogonal focal lengths was designed, in which the aperture of a single lens was 100 μm. The square arrangement improves pixel utilization, the four focal lengths increase the depth of field, and the aspheric improves image quality. The simulations demonstrate pixel utilization rates exceeding 90%, depth-of-field ranges 6.57 times that of a single focal length, and image quality is significantly improved. We have provided a potential solution for improving the depth of field and image quality of the light field imaging system.

Efficacy of Combining Highly Aspherical Lenslets Spectacles With 0.01% Atropine Eye Drops in Myopia Control

To explore the difference in myopia control efficacy between spectacle lenses with highly aspherical lenslets (HAL) combined with 0.01% atropine eye drops and spectacle lenses with HAL alone or single vision spectacle lenses (SVL) in children and adolescents. A retrospective cohort study was conducted with a total of 105 myopic children aged 6-15 years. According to the specific myopia correction and control methods of each subject, they were evenly divided into the HAL+0.01% atropine (HAL+AT) group, the HAL group, and the SVL group, with 35 subjects in each group. Relevant data, such as cycloplegic refraction and axial length (AL) at baseline and 12 months after wearing spectacles, were retrieved. One-way analysis of variance, or the Kruskal-Wallis test, was used to analyze the changes in AL and spherical equivalent refraction (SER) after wearing spectacles for 12 months in comparison to those at baseline in the three groups. There was no statistically significant difference in the baseline parameters and duration of wearing spectacles among the three groups (P>0.05). After wearing spectacles for 12 months, the changes in SER were －0.13 (－0.25, 0.00) D, －0.25 (－0.63, －0.25) D, and －0.63 (－1.00, －0.25) D in the HAL+AT group, HAL group, and SVL group, respectively; AL elongation in the three groups was (0.09±0.11) mm, (0.19±0.16) mm, and (0.34±0.16) mm, respectively. The HAL+AT group exhibited slower SER changes (P HAL+AT vs. HAL=0.001, P HAL+AT vs. SVL=0.002) and AL elongation (P HAL+AT vs. HAL=0.009, P HAL+AT vs. SVL=0.001) than those of the HAL and the SVL groups. Compared with those of the SVL group, myopia progression was reduced by 79.4% and AL elongation was slowed down by 73.5% in the HAL+AT group, while in the HAL group, myopia progression and AL elongation were reduced by 60.3% and 44.1%, respectively. According to stratified analysis based on age and myopia progression rate, among younger children aged 6 to 8 years and older children aged 9 to 15 years, the HAL+AT group had a significantly lower proportion of subjects experiencing fast AL elongation (AL>0.36 mm/year) and a significantly higher proportion of subjects experiencing slow AL elongation (AL≤0.18 mm/year) compared to the SVL group (P<0.017). The combination intervention of spectacle lenses with HAL and 0.01% atropine eye drops is effective in controlling myopia progression in children and adolescents, with better myopia control effect achieved using this combination intervention in myopic children of all ages.

Image restoration for spatially varying degradation based on PSF properties

The single-lens imaging system enhances image quality through restoration algorithm, which has the advantage of miniaturization compared with complex multi-element lens. However, in the design of large field of view (FoV), the single lens faces greater challenges in correcting off-axis aberrations compared to complex multi-element lens. It is more susceptible to spatially varying degradation, and the Point Spread Function (PSF) exhibits significant spatial variation. The previous restoration methods are not accurate in the representation of PSF model with spatial variation, and have limited effect on the blur restoration of large FoV single lens. In this work, we perform more accurate characterization of PSF’s change pattern property as well as shape and energy distribution property. To this end, we first use a PSF changing pattern fitting process to obtain the PSF continuous changing pattern of the whole FoV. This pattern is then used as a prior input into a spatially varying restoration network to achieve the restoration results. The results on the simulation dataset show that our design can improve the PSNR from 20.37 to 28.62, and can achieve a large FoV imaging system of 84°, while we still get better performance than the previous method on the real shot dataset.

Harnessing surface plasmon polaritons from nanogroove plasmonic lenses to enhance the EM fields around plasmonic nanoantennas

In this paper, we present a device—consisting of a bowtie nanoantenna surrounded by either an asymmetric plasmonic nanogroove or a symmetric plasmonic nanogroove—that allows improved excitation of the bowtie nanoantenna via interaction between the bowtie nanoantenna and the surface plasmon polaritons (SPPs) generated from the nanogrooves. We study the effect of both a linear plasmonic nanogroove as well as a circular plasmonic nanogroove (i.e., a circular nanogroove plasmonic lens) on the EM fields around a bowtie nanoantenna placed at a certain distance from the nanogroove. We show that the electric field enhancement of a bowtie nanoantenna can be significantly improved by the interaction between the bowtie nanoantenna and the SPPs generated from the nanogrooves. We employed FDTD simulations to calculate quantities such as the electric field enhancements and power coupling into SPPs as well as a finite difference eigenmode solution to obtain dispersion relation of the nanogrooves. The geometrical parameters of the symmetric nanogroove and asymmetric nanogroove were optimized to couple maximum light into SPPs. We show that the bowtie nanoantenna surrounded by a single asymmetric nanogroove plasmonic lens produces a SERS electromagnetic enhancement factor (EMEF) of 1010—even when the gap between the arms of the bowtie nanoantenna is as large as 10 nm—which is three orders of magnitude higher than SERS EMEF of a stand-alone bowtie nanoantenna and one order of magnitude higher than the SERS EMEF of a bowtie nanoantenna surrounded by a single symmetric nanogroove plasmonic lens. In addition, the effect of the radius of nanogroove plasmonic lenses is studied. The calculation of collection efficiencies of Raman signal from the proposed nanostructures shows that ∼62% Raman signal can be collected from the bowtie nanoantenna surrounded by a symmetric nanogroove plasmonic lens or an asymmetric nanogroove plasmonic lens (PL) compared to 10% Raman signal collected from only a bowtie nanoantenna on a silica substrate.

Myopia Control Effect of Defocus Incorporated Multiple Segments (DIMS) Spectacle Lens in Pakistani Children

Background: Myopia is a growing concern globally, particularly among school-aged children, leading to severe ocular complications if untreated. Objective: The purpose of this research was to determine the effectiveness of DIMS spectacle lenses in preventing myopia progression in Pakistani children. Methods: The current study was tested clinically for two years with two hundred myopic youngsters aged six to twelve years. The subjects were divided into two groups; the first group received DIMS lenses while the second group received single vision lenses. Biometry of the axial length was done using the IOL Master 500 (Carl Zeiss Meditec) and the cycloplegic autorefraction was done using the Topcon KR-800S. For monitoring the progression of myopia, axial length measurements and cycloplegic autorefraction were performed with an interval of six months. Quantitative data were analysed using independent t-tests and mixed-effects models in order to compare the results between the groups. Results: Comparing the DIMS group to the single vision lens group, the children in the former demonstrated slower myopia development. Whereas the control group's mean myopic shift was -0.67 ± 0.30 D/year, the DIMS groups was -0.32 ± 0.25 D/year (p &lt; 0.001). Significantly less axial length changes (0.15 ± 0.10 mm/year) were seen in the DIMS group as compared to the control group (0.31 ± 0.12 mm/year) (p &lt; 0.001). Conclusion: DIMS spectacle lenses are effective in preventing the progression of myopia in Pakistani children. Their use could be a viable approach to managing myopia in this population. However, the study is limited by its short follow-up period and the lack of data on long-term outcomes.

Visual impact of diffusion optic technology lenses for myopia control.

To assess the visual impact of Diffusion Optics Technology™ 0.2 DOT lenses (SightGlass Vision Inc.) designed for myopia control on primary gaze. DOT spectacle lenses contain light scattering elements that scatter light as it passes through the lens which, in turn, reduces retinal image contrast. Fifty-one children (12.2 ± 1.3, range 10-14 years; 51% females) were randomly assigned to wear DOT spectacle (n = 27) or single vision lenses (n = 24) across six investigational sites in North America. Binocular high- and low-contrast distant visual acuities, near visual acuity, reading speed, contrast sensitivity, stereoacuity and glare were assessed in primary gaze after at least 3 years of wear, with the study 95% powered in all metrics to detect significant differences between the groups. Mean binocular distance high-contrast (-0.09 ± 0.02 vs. -0.08 ± 0.02 logMAR, p = 0.81), low-contrast (0.05 ± 0.02 vs. 0.07 ± 0.02 logMAR, p = 0.52) and near visual acuity with glare sources (-0.06 ± 0.03 vs. -0.09 ± 0.03 logMAR, p = 0.32) were similar for DOT and single vision lens wearers, respectively. Contrast sensitivity was similar between children wearing DOT or single vision lenses across 11 of the 16 spatial frequencies (p > 0.05). Mean stereopsis was similar (p = 0.30) with the DOT lenses (33.2 ± 12.5″) and single vision lenses (38.1 ± 14.2″). Functional reading speed metrics were similar in both study groups, as was the objectively measured head tilt during reading (p > 0.05). The mean halo radius was 0.56° ± 0.17° with the DOT lenses compared with 0.50° ± 0.12° with single vision lenses (p = 0.02), but the statistically significant difference was smaller than the non-inferiority bound of 0.4°. Diffusion optics technology lenses provide a clinically equivalent visual experience to a standard single vision lens.

Subjective impressions with myopia control contact lenses versus single vision lenses: A systematic review and meta-analysis

PurposeTo gain insight into patients’ visual experiences and satisfaction when using different forms of myopia control lenses. MethodsPubMed, Cochrane Library, Embase, Scopus and Web of Science databases were searched for articles assessing subjective visual quality with myopia control lenses compared with single-vision lenses (SVLs) up to July 10, 2023. Eight-hundred-and-three articles were retrieved, reviewed and any questionnaire items on subjective impressions of lens wear were meta-analysed. Subgroup analyses were based on the magnitude of defocus (add power) of multifocal soft contact lenses (MFSCLs) and age groups. A random-effects model was employed for meta-analysis, and I2 statistic used to assess the statistical heterogeneity. ResultsNineteen articles fit the criteria, but only six articles involving MFSCLs had relevant data. MFSCLs were associated with lower subjective ratings of vision at different distances compared to SVLs (p < 0.001), but the differences were less than one unit. MFSCLs also yielded lower ratings when moving or walking and/or climbing stairs at −0.38 (−0.69 to −0.07, p = 0.02; I2 = 85 %, p < 0.001) and for subjective comfort (difference of −0.23, −0.41 to −0.05, p = 0.01; I2 = 63 %, p < 0.001). Subjective ratings for playing sports were not different between groups. Experience with MFSCLs was rated lower by young adults compared to children for all variables. In both children and young adults, ratings were lower with higher add compared to lower add MFSCLs. ConclusionAlthough subjective ratings for vision and comfort were lower with MFSCLs compared to SVLs, the difference was mostly less than one unit. Importantly, young adults rated their visual experience lower compared to children.

Spectacle Lenses With Highly Aspherical Lenslets for Slowing Axial Elongation and Refractive Change in Low-Hyperopic Chinese Children: A Randomized Controlled Trial

Purpose: Spectacle lenses with highly aspherical lenslets (HAL) have been shown to effectively retard myopia progression in myopic children. This study aimed to investigate the impact of spectacle lenses with HAL on refractive and axial length (AL) changes in Chinese children with low amount of hyperopia. Design: Randomized controlled trial Methods: A total of 108 Chinese children aged 6.0 to 9.9 years and spherical equivalent refractive error (SERE) from 0.00 to +2.00 D were randomly allocated into two groups: the HAL group and the single vision spectacle lens (SVL) group. Cycloplegic refraction, AL, and uncorrected visual acuity (UCVA) was measured at baseline, three months, six months, and 12 months after lens dispensing. The duration of spectacle lens wear was monitored using a wearable device attached to the spectacle frame and by questionnaire logs provided by participants at each follow up visit. Results: The one-year SERE change was -0.19 [-0.32, 0.03] D and −0.23 [-0.36, 0.05] D in the SVL and HAL groups (P=0.883). The one-year AL elongation was 0.24 [0.18, 0.34] mm and 0.19 [0.12, 0.27] mm in the SVL and HAL groups (P=0.057). In the HAL group, changes in AL and SERE were significantly correlated to lens wearing time (P<0.001 and P=0.024, respectively). Participants in the HAL group who wore their lenses for more than 30 hours per week had significantly slower AL elongation (0.11 [0.05, 0.17] mm) compared to their SVL counterparts (0.27 [0.21, 0.33] mm) (P<0.001). Conclusion: Spectacle lenses with HAL significantly reduced AL elongation in low hyperopic children who wore lenses for over 30 hours per week. A dose-response relationship was evident with longer lens wearing time associated with less AL change.

Large Fiber Array Spectroscopic Telescope: Optical Design for a Scalable Unit Telescope

The Large Fiber Array Spectroscopic Telescope (LFAST) concept involves the utilization of 2640 individual, 0.76 m “unit telescopes” to collect light from a target object. Through optical fibers, the lights from all telescope foci are directed to a high-resolution spectrograph, with fibers subtending a 1.47 arcsec diameter on the sky. The total light-collecting area of all telescopes combined is 1200 m2. Given the telescope’s application for spectroscopy of seeing-limited images, the need for coherence is eliminated. The primary goal of the LFAST prototype is to demonstrate a telescope design that can be rapidly and cost-effectively replicated to achieve a 1200 m2 collecting area and match the capabilities of extremely large telescopes (ELTs) presently under construction. Engineering, manufacturing, and design challenges unique to LFAST differ significantly from those encountered in traditional ELTs. Considering that the unit telescope is to be replicated thousands of times, reducing the manufacturing cost per telescope is essential. The aim of the described design is to achieve this goal, with strong considerations for manufacturability, alignment, few moving parts, and high yield. Experience from the first prototype unit telescope built in 2022 will be leveraged to build the first 20-unit tracking module in 2024, with a collecting area of a 3.4-m-diameter mirror. The design is minimalistic and features commercial tolerances, thereby ensuring cost-effectiveness in manufacturing, assembly, and alignment processes. Moreover, the telescope is designed to operate at angles as low as 70° from the zenith by laterally translating a single lens to correct for atmospheric dispersion. We present a combined average of over 80% encircled energy across 2640 Monte Carlo trials. Simulations were conducted using commercially specified tolerances and capabilities to model the overall performance of the array.

RTModel: A platform for real-time modeling and massive analyses of microlensing events

Context. The microlensing of stars in our Galaxy has long been used to detect and characterize stellar populations, exoplanets, brown dwarfs, stellar remnants, and all other objects that may magnify the source stars with their gravitational fields. The interpretation of microlensing light curves is relatively simple for single lenses and single sources, but it becomes more and more complicated when we add more objects and take their relative motions into account. Aims. RTModel is a modeling platform that has been very active in the real-time investigations of microlensing events, providing preliminary models that have proven very useful for driving follow-up resources towards the most interesting events. The success of RTModel comes from its ability to carry out a thorough and focused exploration of the parameter space in a relatively short time. Methods. This modeling process is based on three key ideas. First, the initial conditions are chosen from a template library including all possible caustic crossing and approaches. The fits are then made using the Levenberg-Marquardt algorithm with the addition of a bumper mechanism to explore multiple minima. Finally, the basic computations of microlensing magnification are performed by the fast and robust VBBinaryLensing package. Results. In this paper, we illustrate all the algorithms of RTModel in detail with the intention to foster new approaches in view of future microlensing pipelines aimed at massive microlensing analyses.

Three optical intervention methods for low myopia control in children: a one-year follow-up study

ObjectiveThis study aimed to compare the one-year efficacy of myopia prevention and control using three optical intervention methods - single vision lens (SVL), highly aspherical lenslet (HAL), and orthokeratology (OK) lens - in children with low myopia.MethodsA cohort of 150 children aged 7–13 years with low myopia was recruited and divided into three groups: SVL (n = 50), HAL (n = 50), and OK lens group (n = 50), based on their preference for glasses. Follow-up assessments were carried out over one year, focusing on data from the right eye for statistical analysis. Baseline characteristics such as gender, age, axial length (AL), spherical equivalent refractive error (SER), flat keratometry (K1), steep keratometry (K2), anterior chamber depth (ACD), white-to-white corneal diameter (WTW), and non-contact tonometry (NCT) measurements were gathered and compared among the three groups before any intervention. Changes in AL growth after 1 year of intervention were assessed across the three groups. Subsequently, the AL growth control rates between the HAL and OK lens groups were compared, with the SVL group serving as the reference standard.ResultsThe study found no statistically significant variances in baseline characteristics (gender, age, SER, AL, K1, K2, WTW, and NCT) among the SVL, HAL, and OK lens groups (all p > 0.05). Following a one-year intervention, AL growth rates were as follows: HAL group (0.163 ± 0.113 mm) < OK lens group (0.280 ± 0.170 mm) < SVL group (0.516 ± 0.190 mm), with statistically significant disparities (p < 0.05). The HAL group demonstrated a higher 1-year AL growth control rate (68.41%) compared to the OK lens group (45.74%) for children aged 7–13 with low myopia, with a statistically significant differences (p < 0.001). And there was significant difference in the SER change between SVL group and HAL group (p < 0.001).ConclusionCompared to SVL, HAL and OK lens are more effective in controlling axial growth in mild myopia. Specifically, HAL maybe shows superior outcomes in both preventive and corrective measures, also it needs to be supported by more studies from randomized controlled experiments.

Anti-distortion bioinspired camera with an inhomogeneous photo-pixel array

The bioinspired camera, comprising a single lens and a curved image sensor—a photodiode array on a curved surface—, was born of flexible electronics. Its economical build lends itself well to space-constrained machine vision applications. The curved sensor, much akin to the retina, helps image focusing, but the curvature also creates a problem of image distortion, which can undermine machine vision tasks such as object recognition. Here we report an anti-distortion single-lens camera, where 4096 silicon photodiodes arrayed on a curved surface in a nonuniform pattern assimilated to the distorting optics are the key to anti-distortion engineering. That is, the photo-pixel distribution pattern itself is warped in the same manner as images are warped, which correctively reverses distortion. Acquired images feature no appreciable distortion across a 120° horizontal view, as confirmed by their neural-network recognition accuracies. This distortion correction via photo-pixel array reconfiguration is a form of in-sensor computing.

International trends in prescribing toric soft contact lenses to correct astigmatism (2000–2023): An update

PurposeThere have been significant advancements in toric soft contact lens design and manufacturing technology, and increased product availability, over the past half a century. The purpose of this work is to update earlier surveys by describing international trends in toric soft lens fitting between 2000 and 2023, inclusive. MethodAn annual contact lens prescribing survey was sent to eye care practitioners in up to 71 countries between 2000 and 2023, inclusive. Data relating to 220,934 standard soft daily wear single vision lens fits undertaken in 20 countries returning reliable longitudinal data were analysed in respect of toric soft lens fitting. ResultsOverall, toric soft lens prescribing almost doubled over the time-course of this survey, from 24.4 % of standard soft daily wear single vision lens fits in 2000 to 46.2 % in 2023 (p < 0.0001). There were significant differences between countries in toric soft lens prescribing (p < 0.0001). Of all standard soft daily wear single vision contact lenses prescribed to males, 32.0 % were toric soft lenses, compared with 28.7 % for females (p < 0.0001). The mean age of toric soft lens wearers was 30.5 ± 12.5 years, compared to 27.9. ± 12.1 years for spherical soft lens wearers (p < 0.0001). Analysis of 13,582 recent toric soft lens fits (2019–2023, inclusive), in terms of material type and replacement frequency, revealed the following proportions: reusable silicone hydrogel – 51 %; daily disposable silicone hydrogel – 27 %; daily disposable hydrogel – 12 %; and reusable hydrogel – 10 %. ConclusionThere has been a substantial increase in toric soft lens fitting throughout the 24 years of this survey, to a point whereby almost all clinically significant astigmatism is being corrected among those wearing standard soft daily wear single vision lenses.

Simultaneous Multifocal Plane Fourier Ptychographic Microscopy Utilizing a Standard RGB Camera.

Fourier ptychographic microscopy (FPM) is a computational imaging technology that can acquire high-resolution large-area images for applications ranging from biology to microelectronics. In this study, we utilize multifocal plane imaging to enhance the existing FPM technology. Using an RGB light emitting diode (LED) array to illuminate the sample, raw images are captured using a color camera. Then, exploiting the basic optical principle of wavelength-dependent focal length variation, three focal plane images are extracted from the raw image through simple R, G, and B channel separation. Herein, a single aspherical lens with a numerical aperture (NA) of 0.15 was used as the objective lens, and the illumination NA used for FPM image reconstruction was 0.08. Therefore, simultaneous multifocal plane FPM with a synthetic NA of 0.23 was achieved. The multifocal imaging performance of the enhanced FPM system was then evaluated by inspecting a transparent organic light-emitting diode (OLED) sample. The FPM system was able to simultaneously inspect the individual OLED pixels as well as the surface of the encapsulating glass substrate by separating R, G, and B channel images from the raw image, which was taken in one shot.

Adaptive optics in an oblique plane microscope.

Adaptive optics (AO) can restore diffraction-limited performance when imaging beyond superficial cell layers in vivo and in vitro, and as such, is of interest for advanced 3D microscopy methods such as light-sheet fluorescence microscopy (LSFM). In a typical LSFM system, the illumination and detection paths are separate and subject to different optical aberrations. To achieve optimal microscope performance, it is necessary to sense and correct these aberrations in both light paths, resulting in a complex microscope system. Here, we show that in an oblique plane microscope (OPM), a type of LSFM with a single primary objective lens, the same deformable mirror can correct both illumination and fluorescence detection. Besides reducing the complexity, we show that AO in OPM also restores the relative alignment of the light-sheet and focal plane, and that a projection imaging mode can stabilize and improve the wavefront correction in a sensorless AO format. We demonstrate OPM with AO on fluorescent nanospheres and by imaging the vasculature and cancer cells in zebrafish embryos embedded in a glass capillary, restoring diffraction limited resolution and improving the signal strength twofold.

Best practice in audiology: context matters

Historically, modern audiology evolved from the United States of America (USA) after the Second World War, where hearing rehabilitation programs were established across the country. Since then, audiology practice and the profession as a whole has expanded from the west to the far east and global south with considerable contextual variations. Thus, the purpose of this paper is to increase conversation and engagement on definitions and the drawbacks of a single lens approach to the use of best practice guidelines in Audiology. It is important to develop a more expansive lens as influenced by different contexts such as Africa, Asia, and South America that will in turn help facilitate a multidimensional approach to audiology practice and what is considered “best practice.”