Transfer Function Curves Research Articles

Impact of pupil size and corneal spherical aberrations on the performance of monofocal intraocular lenses: an experimental model

In this study, an in vitro comparison of the optical performances of three models (spherical, aberration-neutral, and aberration-correcting) of monofocal intraocular lenses (IOLs) is proposed. A comprehensive model is employed, encompassing a wide range of corneal models and aperture sizes, reflecting the high variability of corneal spherical aberrations (SA) and pupil sizes in both normal and postoperative refractive corneal surgery populations. Analysis of average through-focus modulation transfer function (MTF) curves reveals significant differences in optical performance attributable to pupil size and corneal SA. These differences depend on the IOL model and affects MTFmax (representing contrast at best focus), depth of focus, refractive error tolerance, and the effective power of the lens.

Research on an Active Adjustment Mechanism Based on Non-Singular Terminal Sliding Mode and Finite-Time Disturbance Observer

With the continuous development of synchrotron radiation light sources, higher requirements have been put forward for the stability of double-crystal monochromators in synchrotron radiation facilities. This paper designs an active adjustment mechanism for a double-crystal monochromator to improve its stability. Firstly, three spatial degrees of freedom are designed based on the active adjustment mechanism of flexible leaf spring parallel coupling, and the prototype of the mechanism is fabricated. Secondly, system identification experiments are carried out and the system transfer function curve is fitted by the nonlinear least squares method. Thirdly, the controller based on non-singular terminal sliding modes and a finite-time disturbance observer was designed for stability control and disturbance compensation. Finally, the effectiveness of the controller is verified by a model-in-the-loop approach based on the performance of the real-time target machine. The results show that the non-singular terminal sliding mode + finite-time disturbance observer control strategy can reduce the RMS value of the vibration displacement of Axis-1/Axis-2/Axis-3 by 81.25%, 78.53%, and 71.82%.

Tolerance to decentration of biaspheric intraocular lenses with refractive phase-ring extended depth of focus and diffractive trifocal designs

PurposeThis study aimed to investigate the in vitro tolerance to decentration of biaspheric intraocular lens (IOLs) with refractive phase-ring extended depth-of-focus (EDOF) and diffractive trifocal designs.MethodsThis experimental study was carried out at the Department of Optics and Optometry and Vision Science, University of Valencia, Spain. The modulation transfer function (MTF) of the ETLIO130C EDOF and the TFLIO130C trifocal IOLs (AST Products Inc., Billerica, MA, USA) were determined at different levels of decentration for a given wavelength and pupil diameter using the PMTF optical bench (Lambda-X Ophthalmics, Nivelles, Belgium). The modulation transfer function (MTF) curves, the through-focus MTF curves, and the Strehl ratios were measured at 3-mm pupil aperture for 0.25-, 0.50- and 0.75-mm decentration.ResultsThe optical design of the trifocal TFLIO130C IOL is robust to small decentrations, with virtually no change in MTF response for 0.25 mm decentration. For greater decentration levels, the MTF response is slightly reduced with increasing decentration. The ETLIO130C EDOF design is robust to decentration, as the MTF response is only minimally affected when increasing the decentration up to 0.75 mm.ConclusionsMTF responses are slightly reduced with greater levels of decentration, but the range of focus provided by both trifocal and EDOF designs are preserved. The effects for average levels of decentration reported in the literature are minimum for both IOL designs.

Lightweight and High-Stiffness Metal Optical Systems Based on Additive Manufacturing.

To build a long-wave infrared catadioptric optical system for deep space low-temperature target detection with a lightweight and wide field of view, this work conducted a study that encompasses a local cooling optical system, topology optimization-based metal mirror design, and additive manufacturing. First, a compact catadioptric optical system with local cooling was designed. This system features a 55 mm aperture, a 110 mm focal length, and a 4-degree by 4-degree field of view. Secondly, we applied the principles of topology optimization to design the primary mirror assembly, the secondary mirror assembly, and the connecting baffle. The third and fourth modes achieved a resonance frequency of 1213.7 Hz. Then, we manufactured the mirror assemblies using additive manufacturing and single-point diamond turning, followed by the centering assembly method to complete the optical assembly. Lastly, we conducted performance testing on the system, with the test results revealing that the modulation transfer function (MTF) curves of the optical system reached the diffraction limit across the entire field of view. Remarkably, the system's weight was reduced to a mere 96.04 g. The use of additive manufacturing proves to be an effective means of enhancing optical system performance.

Comparison of astigmatism correction and visual outcomes in mix-and-match implantations of trifocal intraocular lenses with femtosecond laser-assisted arcuate keratotomy and contralateral bifocal Toric intraocular lenses.

Astigmatism reduces the postoperative visual performance after non-toric intraocular lenses (IOLs) implantation, and limits the use of refractive IOLs in cataract surgery. The purpose of this study was to compare the efficacy in astigmatism correction and the postoperative visual outcomes between the implantation of a trifocal IOL with femtosecond laser-assisted arcuate keratotomy (FSAK) in one eye and a bifocal toric IOL (TIOL) in the other, in patients with cataract and moderate astigmatism. This prospective observational paired-eye study enrolled patients with cataract and corneal astigmatism (CA) between 0.75 and 2.25 D in both eyes. The patients underwent a mix-and-match treatment comprising trifocal IOL implantation with FSAK and bifocal TIOL implantation. We compared the visual acuity (VA) at all distances, defocus curve, postoperative refractive astigmatism (RfA), CA, high-order aberrations, modulation transfer function (MTF) curve, and Strehl ratio between the two eye groups. In total, 41 patients (82 eyes) were enrolled and completed a 6-month follow-up. The 1- and 3-month uncorrected distance VA and 3-month uncorrected near VA were greater in eyes with bifocal TIOLs than with trifocal IOLs and FSAK (p = 0.036, 0.010, and 0.030, respectively), whereas the latter had greater uncorrected intermediate VA at every visit and greater VA in the intermediate range of defocus curve (at -1.50 and - 2.00 D) than the eyes with bifocal TIOLs. The postoperative RA of the eyes with trifocal IOL and FSAK was significantly higher than that of the bifocal TIOL-implanted eyes at the 3- and 6-month follow-ups. Both FSAK and TIOL implantation effectively reduce pre-existing moderate astigmatism in patients with cataract. The eyes with bifocal TIOLs had more stable long-term astigmatism correction, whereas those with trifocal IOLs and FSAK had better intermediate VA. Therefore, a mix-and-match implantation of trifocal IOL with FSAK and contralateral bifocal TIOL could achieve effective astigmatism correction and provide an overall optimal VA.

Optical Performance of a Segmented Extended-Depth-of-Focus Intraocular Lens under the Influence of Different Values of Spherical Aberration Generated by Refractive Surgery.

Corneal refractive surgery induces high-order aberrations, specifically spherical aberration (SA). These aberrations can have implications when patients later develop cataracts and require the implantation of multifocal intraocular lenses (MIOLs). MIOLs with asymmetric designs pose challenges in predicting outcomes, particularly in these cases. The aim of this study was to evaluate how different values of SA, resulting from various types of refractive surgeries, affect the optical performance of the FEMTIS Comfort intraocular lens. The through-focus modulation transfer function (TF-MTF) curve and high-contrast images of tumbling E were used as parameters to assess the optical performance of the MIOL. These parameters were measured using an adaptive optics visual simulator. Increasingly negative values of SA make the MIOL more bifocal, moderating its extended-depth-of-focus characteristic. Conversely, higher positive SA values cause the TF-MTF curve to shift towards positive vergences, leading to worsened distance vision in the +1.00 to +2.00 D range, but improved vision in the +0.50 D to +1.00 D range. Assessing SA in patients prior to implanting MIOLs with asymmetric designs is necessary for predicting outcomes and making informed decisions based on the visual requirements of patients.

Effect of postoperative residual astigmatism on visual outcomes after trifocal intraocular lens implantation.

The aim of this study was to evaluate the effect of residual astigmatism on postoperative visual outcomes after trifocal intraocular lens implantation. In this prospective observational study, we divided 156 eyes into two groups according to postoperative astigmatism measured by subjective optometry and followed them up for 3 months. Visual acuity, modulation transfer function (MTF) curves, Strehl ratio (SR), Visual Function Index-14 scores, and photic phenomena were compared. Linear regression analysis revealed a weak correlation between residual astigmatism and uncorrected distance visual acuity (UDVA) (r = 0.190, P = 0.016) at 3 months and a significant between-group difference at 1- and 3-month postoperative UDVA (P = 0.038, P = 0.018, respectively). MTF curve values and SR (MTF-10 total, MTF-10 cornea, MTF-30 total, MTF-30 cornea, SR Total, and SR cornea) were significantly worse (P < 0.001), and the Visual Function Index-14 scores were lower in the 0.5 < astigmatism ≤ 1.25 D group (P < 0.05) than in the astigmatism ≤ 0.5 D group. No significant differences were found in the frequency, severity, and bothersomeness of photic phenomena (P > 0.05). Postoperative residual astigmatism affects the UDVA of the trifocal intraocular lens-implanted eyes. Although we found no significant differences in uncorrected intermediate and near visual acuity, both objective and subjective visual quality were affected, suggesting the need for surgical planning when the anticipated postoperative astigmatism is >0.5 D.

Comparison of visual outcomes in adult patients with different types of developmental cataracts after toric multifocal intraocular lenses implantation

Purpose To analyze and compare the visual performance and patient satisfaction following the implantation of toric multifocal intraocular lenses (TMIOLs) in adult patients with different types of developmental cataracts (DC) accompanied by corneal astigmatism (CA).Methods This is a prospective observational cohort study. Patients diagnosed with DC aged 18–30 years were divided into three groups according to the anatomic location of the lens opacity: cortical, nuclear, and posterior subcapsular (PSC) groups, and implanted with TMIOLs. Visual acuity (VA), postoperative refractive astigmatism (RA), intraocular lens (IOL) rotation, high-order aberrations (HOAs), modulation transfer function (MTF) curve, and Strehl ratio were compared. The functional vision and incidence of photic phenomena were surveyed using questionnaires.Results Fifty-five eyes of 37 patients were enrolled and completed a 1-year follow-up. The mean CA was 2.06 ± 0.79 D preoperatively, and the mean RA was 0.29 ± 0.30 D 3-month postoperatively. The IOL rotation was 2.48° ± 1.89°, with no deviation > 10°. At 12 months, mean uncorrected distance VA improved from 0.93 ± 0.41 preoperatively to 0.08 ± 0.08 logarithm of the minimum angle of resolution (logMAR), mean uncorrected near VA increased from 0.45 ± 0.30 preoperatively to 0.12 ± 0.11 logMAR, and mean uncorrected intermediate VA was 0.14 ± 0.08 logMAR. The cortical and nuclear groups displayed better improvements in uncorrected near and intermediate VA than that in the PSC group. Similar results were observed in the 3-month defocus curves, HOAs, MTF curve, halo incidence, and near vision satisfaction.ConclusionIn adult patients with DC accompanied by CA, TMIOLs implantation achieved good postoperative visual outcomes and significantly reduced glasses dependency. Patients with cortical or nuclear lens opacity showed better whole-course VA and quality of vision, while patients with PSC opacity showed unsatisfactory near vision and suffered more photic phenomena.

Uniform design and deep learning based liquid lens optimization strategy toward improving dynamic optical performance and lowering driving force.

An efficient optimization strategy for liquid lens combining the uniform design and the deep learning is proposed to achieve improved dynamic optical performance and lowering driving force simultaneously. The membrane of the liquid lens is designed into a plano-convex cross-section, in which the contour function of the convex surface as well as the central membrane thickness is especially optimized. The uniform design method is initially utilized to select a part of uniformly distributed and representative parameter combinations from all possible parameter range, and their performance data is then obtained through simulation using MATLAB to control COMSOL and ZEMAX. After that, a deep learning framework is employed to build a four-layer neural network with its input and output layer representing the parameter combinations and the performance data, respectively. After 5 × 103 epochs, the deep neural network has undergone sufficient training, demonstrating effective performance prediction capability for all parameter combinations. Finally, a "globally" optimized design can be obtained by setting appropriate evaluation criteria which take the spherical aberration, the coma and the driving force into consideration. Compared with the conventional design using uniform membrane thickness of 100 µm and 150 µm as well as the previously reported "locally" optimized design, distinct improvements in the spherical and the coma aberrations across the entire focal length tuning range have been achieved, whilst the required driving force is largely reduced. In addition, the "globally" optimized design exhibits the best modulation transfer function (MTF) curves and provides the best image quality.

Binocular Visual Outcomes Comparison of Two Trifocal Intraocular Lenses in High-Myopic Cataract Patients: A 1-Year Multicenter Study

To compare the postoperative visual outcomes and quality of vision obtained with 2 types of diffractive trifocal intraocular lenses (IOLs) in patients with highly myopic cataracts. Prospective, multicenter, randomized controlled trial. Patients with high-myopic cataracts were randomized to binocular implantation of either the TFNT00 (n=27) or the 839 MP (n=28) trifocal IOLs at 3 surgery centers in China and were followed up for 1 year. Postoperative uncorrected distance, uncorrected intermediate, and uncorrected near visual acuity, and best-corrected distance visual acuity were measured. The defocus curve, high-order aberrations, modulation transfer function curve, Strehl ratio, and reading ability were compared between both groups. The functional vision and incidence of photic phenomena were surveyed using questionnaires. Visual acuity at all ranges of vision was significantly improved in both groups. The TFNT00 group showed superior uncorrected intermediate visual acuity to that in the 839 MP group (P=.013). Reading ability at 40 and 60 cm was similar in both groups (P ≥ .05), whereas the preferred reading distances for near and intermediate were significantly different. The TFNT00 group had a significantly higher mean Visual Function Index 14 score, lower incidence of photic phenomena, and less posterior capsular opacity than the 839 MP group. Bilateral implantation of both types of trifocal IOLs in patients with high-myopic cataracts provided good whole-course visual restoration, although recognition of fine Chinese characters remained impeded. As compared with 839 MP IOL, TFNT00 IOL resulted in greater patient satisfaction in intermediate activities, with a lower photic phenomena incidence.

Super-resolution image reconstruction from sparsity regularization and deep residual-learned priors.

Computed tomography (CT) plays an important role in the field of non-destructive testing. However, conventional CT images often have blurred edge and unclear texture, which is not conducive to the follow-up medical diagnosis and industrial testing work. This study aims to generate high-resolution CT images using a new CT super-resolution reconstruction method combining with the sparsity regularization and deep learning prior. The new method reconstructs CT images through a reconstruction model incorporating image gradient L0-norm minimization and deep image priors using a plug-and-play super-resolution framework. The deep learning priors are learned from a deep residual network and then plugged into the proposed new framework, and alternating direction method of multipliers is utilized to optimize the iterative solution of the model. The simulation data analysis results show that the new method improves the signal-to-noise ratio (PSNR) by 7% and the modulation transfer function (MTF) curves show that the value of MTF50 increases by 0.02 factors compared with the result of deep plug-and-play super-resolution. Additionally, the real CT image data analysis results show that the new method improves the PSNR by 5.1% and MTF50 by 0.11 factors. Both simulation and real data experiments prove that the proposed new CT super-resolution method using deep learning priors can reconstruct CT images with lower noise and better detail recovery. This method is flexible, effective and extensive for low-resolution CT image super-resolution.

Using symmetric illumination and color camera to achieve high throughput Fourier ptychographic microscopy.

This study aims to develop a high throughput Fourier ptychographic microscopy (FPM) technique based on symmetric illumination and a color detector, which is able to accelerate image acquisition by up to 12 times. As an emerging technology, the efficiency of FPM is limited by its data acquisition process, especially for color microscope image reconstruction. To overcome this, we built an FPM prototype equipped with a color camera and a 4×/0.13 NA objective lens. During the image acquisition, two symmetric LEDs illuminate the sample simultaneously using white light, which doubles the light intensity and reduces the total captured raw patterns by half. A standard USAF 1951 resolution target was used to measure the system's modulation transfer function (MTF) curve, and the H&E-stained ovarian cancer samples were then imaged to assess the feature qualities depicted on the reconstructed images. The results showed that the measured MTF curves of red, green, and blue channels are generally comparable to the corresponding curves generated by conventional FPM, while symmetric illumination FPM preserves more tissue details, which is superior to the results captured by conventional 20×/0.4 NA objective lens. This investigation initially verified the feasibility of symmetric illumination based color FPM.

Theoretical and experimental investigation on disc spring isolation system with loading rings

A novel disc spring isolation system (DSIS) design for buildings is proposed to isolate vibrations in the vertical direction. The system with nonlinear stiffness consists of disc springs and loading rings that reduce the influence of Coulomb friction between multiple disc springs. Theoretical analysis was first applied to establish a four-curve (FC) model to describe the force-displacement relation of DSIS by considering the influence of slip behavior and Coulomb friction between the loading rings and disc springs. Then, a series of vertical cyclic loading tests were carried out to study the different mechanical properties of DSIS with or without loading rings, and the effectiveness of the loading rings was verified. By comparing with the test results, the accuracy of the proposed FC model was verified. Then, the numerical solution method using the proposed FC model to solve the dynamic response of the single degree of freedom (SDOF) system was investigated. The nonlinear transfer function curves of DSIS with loading rings were compared with those of DSIS without loading rings by numerical analysis. Finally, the comparison study of SDOF for DSIS under the specific harmonic and train-induced vibration was carried out as a case study. The comparison shows that DSIS with loading rings more effectively reduces the start frequency of the isolated system, revealing the significant advantages of adopting DSIS with loading rings in vertical isolation.

Optical design of athermalized infrared dual-band annular folded lens with multilayer imaging diffractive optical elements

In order to realize the miniaturization of the infrared dual-band imaging system, a common optical path annular folded lens (AFL) with multilayer imaging diffractive optical element (MIDOE) is designed in this paper. The design principle of the AFL is studied, and the relationship between the obscuration ratio and the field of view is given. For the wide temperature range, the theoretical model of the optimal substrate materials selection for the MIDOE is established to achieve the high diffraction efficiency. According to theory analysis, the infrared dual-band AFL with IRG26-ZNS MIDOE is designed in the mid-wave infrared (MWIR) 3∼5 μm and long-wave infrared (LWIR) 8∼12 μm. The focal length is 50 mm, the equivalent F number is 1, and the full field of view is 14 ° The modulation transfer function (MTF) curves of each field of view are close to the diffraction limit when the spatial frequency is 20lps/mm, and the MTF values are greater than 0.61 and 0.28 in MWIR and LWIR, respectively. When the ambient temperature ranges from -40 °C to 80 °C, the high image quality is achieved in dual-band. In addition, the tolerance analysis is performed to verify machinability of the system. The research in this paper has important significance for the realization of a new generation of the low-cost, integrated dual-band imaging system.

Design and application of a spherical aberration free continuous zoom liquid-filled micro-cylindrical lenses system

A zoom system named liquid-filled micro-cylindrical lenses integrating a capillary and a biconvex micro-cylindrical lens in a polydimethylsiloxane (PDMS) substrate is designed, which can achieve continuous changed focal length from 2.675 to 9.012 mm by injecting variable concentrations of glycerol aqueous solution into the capillary. The aberration fan diagrams, root mean square spot radius, peak-to-valley wavefront aberration, and modulation transfer function curves at different zoom configurations of the liquid-filled micro-cylindrical lenses are all analyzed, showing good imaging quality over the whole focal length range. And an anamorphic zoom system for uniform collimated beam is designed putting such two PDMS substrates similar as the Kepler telescope structure. The anamorphic system can realize the zoom shaping function with 1:2 to 2:1 aspect ratio beam conversion without machine movement along optical axis and with no significant aberration. The introduced zoom system is characterized by high image quality, small volume, and a simple and stable structure, providing a design idea for cylindrical lenses with variable focal length.

Focusing Characteristics and Widefield Imaging Performance of the Silicon Metalens in the Visible Range

Conventional optical high numerical aperture lenses are essential for high-resolution imaging, but bulky and expensive. In comparison, metalens-based optical components are the subjects of intensive investigation for their flexible manipulation of light. Methods of detecting and characterizing focal spots and scanning imaging produced by metalenses are well established. However, widefield imaging by metalenses is experimentally challenging. This study demonstrates the design and realization of silicon-based metalenses with numerical apertures of 0.447 and 0.204 in the broadband spectrum of 580–780 nm for microscopic widefield imaging. The optimized aspect ratio of the single nanorod is 5.1:1, which reduces the fabrication difficulty compared to other, more complicated designs and fabrication. Furthermore, we successfully demonstrate widefield imaging by the designed metalens and compare the simulated and the experimentally extracted modulation transfer function curves of the metalens.

Intensifying the spatial resolution of 3D thermal models from aerial imagery using deep learning-based image super-resolution

Nowadays, 3D thermal models can play an important role in buildings' energy management while acquiring multisource data to generate a high-resolution 3D thermal model. Consequently, in this article, a method for intensifying 3D thermal model using deep learning-based image super-resolution is presented. In the proposed method, first, the enhanced deep residual super-resolution (EDSR) deep network is re-trained based on thermal aerial images. Second, the resolution of low-resolution thermal images is enhanced using the newly trained network. Finally, the state-of-the-art structures from motion (SfM), semi global matching (SGM) and space intersection are utilized to generate intensified 3D thermal model from the resolution enhanced thermal images. Spatial evaluations indicate a 5% increase in edge-based image fusion metric (EFM) for the intensified 3D model. Besides, the evaluations show that the modulation transfer function (MTF) curves of the intensified 3D thermal model are closer to a reference model against the original 3D thermal model. Highlights A 3D thermal model intensification solution using EDSR is proposed which is independent of hardware techniques and multisource data. Considering the importance of edge sharpness in the intensified 3D thermal model, the quality of edges is assessed using MTF curves and the EFM metric. In comparison to the original 3D thermal model, the MTF curves of the intensified 3D thermal model are closer to the MTF curve of the high-resolution 3D model. The EFM metric shows higher values for MTF curves of the intensified 3D thermal model against MTF curves of the original 3D thermal model.

Comparison of Visual Outcomes and Quality of Life in Patients with High Myopic Cataract after Implantation of AT LISA Tri 839MP and LS-313 MF30 Intraocular Lenses.

Purpose To investigate the benefits of multifocal lens in patients with high myopic cataract and compare the clinical effects between AT LISA tri 839MP and MPlus LS-313 MF30 intraocular lenses (IOLs) in high myopic eyes. Methods This retrospective cohort study analyzed 60 eyes with axial length >26 mm in 40 patients. Thirty eyes were implanted with MF30, and the remaining 30 eyes were implanted with 839MP. Postoperative uncorrected distance visual acuity (UDVA), best corrected distance visual acuity (BCDVA), uncorrected intermediate visual acuity (UIVA) and uncorrected near visual acuity (UNVA), defocus curve, modulation transfer function (MTF) curve, Strehl ratio (SR), and complications were compared between the two groups. Results All vision outcomes were significantly improved in both groups (p < 0.05). There was no significant between-group difference in UDVA at 1 and 3 months postoperatively (p > 0.05). However, UIVA and UNVA were significantly better in the 839MP group (p < 0.05). The VF-14 score, especially for near vision quality, was significantly higher in the MF30 group (2.2 ± 0.9 vs. 0.8 ± 0.7; p ≤ 0.001). The SR of both groups significantly increased postoperatively (p < 0.05). All the 3-month MTF curve values (MTF 10 total, MTF 10 internal, MTF 30 total, and MTF 30 internal) were significantly better in the 839MP group (p < 0.05). Meanwhile, all the high-order aberration values (coma, spherical aberration, and trefoil) were significantly greater in the MF30 group (p < 0.05). Conclusion Multifocal IOL implantation achieves good quality of distance, intermediate, and near vision in patients with high myopia, improving their quality of life. Both 839MP and MF30 IOLs can provide good distance vision, but 839MP performs better in near and intermediate vision. However, for some patients with an extra-long optic axis, MF30 may be a good choice because of its wider range of degrees.

Using Fourier ptychography microscopy to achieve high-resolution chromosome imaging: an initial evaluation.

.SignificanceSearching analyzable metaphase chromosomes is a critical step for the diagnosis and treatment of leukemia patients, and the searching efficiency is limited by the difficulty that the conventional microscopic systems have in simultaneously achieving high resolution and a large field of view (FOV). However, this challenge can be addressed by Fourier ptychography microscopy (FPM) technology.AimThe purpose of this study is to investigate the feasibility of utilizing FPM to reconstruct high-resolution chromosome images.ApproachAn experimental FPM prototype, which was equipped with or objective lenses to achieve a theoretical equivalent NA of 0.48 and 0.63, respectively, was developed. Under these configurations, we first generated the system modulation transfer function (MTF) curves to assess the resolving power. Next, a group of analyzable metaphase chromosomes were imaged by the FPM system, which were acquired from the peripheral blood samples of the leukemia patients. The chromosome feature qualities were evaluated and compared with the results accomplished by the corresponding conventional microscopes.Results The MTF curve results indicate that the resolving power of the FPM system is equivalent and comparable to the conventional microscope, whereas the performance of the FPM system is close to the conventional microscope. When imaging the chromosomes, the feature qualities of the FPM system are comparable to the results under the conventional lens, whereas the feature qualities of the FPM system are better than the conventional lens and comparable to the conventional lens.ConclusionsThis study initially verified that it is feasible to utilize FPM to develop a high-resolution and wide-field chromosome sample scanner.

Transverse additive manufacturing and optical evaluation of miniature thin lenses in ultracompact micro multi-spherical compound eye

An ultracompact micro multi-spherical compound eye (MSCE) was designed to solve the defocus problem existing in traditional curved compound eye for planar photoelectric detection. The MSCE was integrated with a series of thin lenses located on multiple spherical surfaces with various radii. The overall diameter of the designed MSCE was 86.3 μm, and it was composed of 37 ommatidia with a diameter of 7.5 μm. The transverse additive manufacturing method via two-photon polymerization (TPP) was used to achieve precise fabrication of MSCE. Comparison experiments were performed to show the superiority of this method in quality and efficiency in thin lenses manufacturing compared with traditional curved compound eye methods. Furthermore, the spot diagrams and Modulation Transfer Function (MTF) curves were used to evaluate the optical imaging. The imaging of letters ‘C’, ‘U’ and ‘T’ through the fabricated MSCE were successfully detected by the established imaging system, respectively. The imaging quality was evaluated using the root-mean-square value in the Hexcone model. The maximum optical intensity of MSCE increased by 63.9% compared with that of a single-spherical compound eye (SSCE). Finally, the actual field of view (FOV) angle of MSCE was detected as ∼80°, which was almost consistent with the theoretical angle of 77.6°. It is expected that this work will promote micro-optics components to be applied in the miniaturization and integration of optics systems for imaging, sensing and illuminating.