Ultra-elongated depth of focus of plasmonic lenses with concentric elliptical slits under Gaussian beam illumination

In this paper, we discuss the influence of ratio of minor to major axis on the propagation property and focusing performance of a plasmonic lens with variant periodic concentric elliptical slits illuminating under a Gaussian beam. In order to analyse the influence theoretically, a finite-difference time-domain （FDTD） numerical algorithm is adopted for the computational numerical calculation and the design of the plasmonic structure. The structure is flanked with penetrated slits through a 200-nm metal film （Au） which is coated on a quartz substrate. Tunability of focusing capability of the plasmonic lenses is studied by tailoring the ratio. Our calculation results demonstrate that the ratio of the elliptical slits greatly affects the focusing capability of the lense. The plasmonic lenses with concentric elliptical slits illuminating under a Gaussian beam have ultra-elongated depth of focus. These results are very encouraging for the future study of the plasmonic lens-based applications.

Visual Performance of a Polynomial Extended Depth of Focus Intraocular Lens

Purpose: To clinically evaluate a new extended depth of focus intraocular lens (ISOPURE, PhysIOL) with optic design modification based on a unique polynomial concept to improve intermediate vision while keeping the quality of distance vision equal to a monofocal lens. Methods: 18 patients (11 female, 7 male, mean age of 69.4 years) with bilateral cataract and regular corneal astigmatism ≤ 1.0 D underwent bilateral cataract surgery with ISOPURE implantation. Patients were followed for up to 6 months. Measured parameters were uncorrected (UDVA) and corrected distance visual acuity (CDVA), uncorrected (UIVA) and distance-corrected intermediate visual acuity at 80 cm and 66 cm (DCI80VA, DCI66VA) subjective refraction, defocus curve, tolerance of cylinder induction, and contrast sensitivity. The data from all implanted eyes (all-eyes) and a subset only including the first eye implanted for each patient were analysed. Results: The mean manifest refraction spherical equivalent (MRSE) decreased from 1.05 D pre-operatively to ?0.15 D at the 4 - 6 month assessment, with 80.6% of eyes within ±0.50 D of emmetropia. At the final follow-up, mean (SD) monocular CDVA was ?0.06 (0.04) logMAR, DCI80VA was 0.18 (0.08) logMAR and DCI66VA was 0.27 (0.13) logMAR. Despite a cylinder induction of ?0.50 D, uncorrected distance visual acuity of 0.02 logMAR was still achieved. Conclusion: The ISOPURE intraocular lens provides excellent distance corrected visual acuity for far and intermediate distances along with high contrast sensitivity and good tolerance of residual refractive cylinder.

Outcomes of a non-diffractive extended depth of focus intraocular lens in patients with well-controlled glaucoma and ocular hypertension

AIM:To assess visual outcomes and satisfaction of a non-diffractive extended depth of focus(EDOF)intraocular lens(IOL)in individuals with ocular hypertension(OHT)and well-controlled mild glaucoma undergoing cataract surgery.METHODS:An investigator-initiated,single-center,prospective,interventional,noncomparative study conducted in Montreal,Canada.The study enrolled 31 patients(55 eyes)with OHT or mild glaucoma who received a non-diffractive EDOF IOL(Acrysof IQ Vivity).Participants underwent sequential cataract surgery with the Vivity IOL.Follow-up evaluations occurred at 1d,1,and 3mo postoperatively,assessing uncorrected distance,intermediate,and near visual acuity.Questionnaires(QUVID:Questionnaire for visual disturbances and IOLSAT:Intraocular lens satisfaction)were administered pre and post-operatively to measure visual disturbances and spectacle independence in various lighting.Safety parameters included intraocular pressure(IOP),glaucoma medications,spherical equivalence,mean deviation and pattern standard deviation or square root of lost variance on Octopus visual field.RESULTS:At 1 and 3mo postoperatively,significant improvements were observed in uncorrected distance and intermediate visual acuity.Spectacle independence was enhanced for distance and intermediate vision,especially in bright light settings.Spectacle-free intermediate vision was improved even in dim lighting.Visual disturbances,particularly glare symptoms,were reduced,and there was a notable decrease in IOP and glaucoma medication burden at 3mo.There was more hazy vision postoperatively with no impact on visual acuity and visual satisfaction.CONCLUSION:The non-diffractive EDOF lens improves distance and intermediate spectacle-free visual function in patients with OHT and well-controlled glaucoma.The findings highlight significant improvements in visual acuity,reduced glare,enhanced spectacle independence,and improved visual performance in different lighting conditions.

Flexible depth-of-focus,depth-invariant resolution photoacoustic microscopy with Airy beam

Optical-resolution photoacoustic microscopy(OR-PAM)has rapidly developed and is capable of characterizing optical absorption properties of biological tissue with high contrast and high resolution(micrometer-scale lateral resolution).However,the conventional excitation source of rapidly diverging Gaussian beam imposes limitations on the depth of focus(DOF)in OR-PAM,which in turn affects the depth-resolving ability and detection sensitivity.Here,we proposed a flexible DOF,depth-invariant resolution photoacoustic microscopy(FDIR-PAM)with nondiffraction of Airy beams.The spatial light modulator was incorporated into the optical pathway of the excitation source with matched switching phase patterns,achieving the flexibly adjustable modulation parameters of the Airy beam.We conducted experiments on phantoms and intravital tissue to validate the effectiveness of the proposed approach for high sensitivity and highresolution characterization of variable topology of tissue,offering a promising DOF of 926μm with an invariant lateral resolution of 3.2μm,which is more than 17-fold larger compared to the Gaussian beam.In addition,FDIR-PAM successfully revealed clear individual zebrafish larvae and the pigment pattern of adult zebrafishes,as well as fine morphology of cerebral vasculature in a large depth range with high resolution,which has reached an evident resolving capability improvement of 62%mean value compared with the Gaussian beam.

Design of double-zone aspheric diffractive intraocular lens with extended depth of focus

A double-zone aspheric diffractive intraocular lens （IOL） was designed and manufactured aiming to regain a continuous range of clear vision for pseudophakic presbyopia. After obtaining the IOL structure parameters through optimization based on an aphakic model eye, its imaging performances were analyzed in the model eye. The modulation transfer function at 50 cycles/mm remained above 0.29 within ±5° field of view for object distance ranging from 6 to 0.66 m. In addition, the imaging qualities are robust for pupil changes, polychromatic light, and different corneal asphericities. The manufactured IOL exhibits the abilitv to extend depth of focus.

Underwater Bessel-like beams with enlarged depth of focus based on fiber microaxicon

Underwater optical wireless communication,which is useful for oceanography,environmental monitoring,and underwater surveillance,suffers the limit of the absorption attenuation and Mie–Rayleigh scattering of the lights.Here,Bessel-like beams generated by a fiber microaxicon is utilized for underwater wireless propagation.Underwater,the cone angle for generating Bessel-like beams starts from 46°,which is smaller than that in air for Bessel-like beams.When the cone angle of the fiber microaxicons is about 140°,the depth of focus underwater,which is four times as long as the depth of focus in air,has enlarged about 28μm,36.12μm,and 50.7μm for 470 nm,520 nm,and 632 nm visible lights.The transmission distance of the Bessel beams for visible lights has been simulated by using Henyey–Greenstein–Rayleigh phase function methods and spectral absorption by bio-optical model due to Monte Carlo methods.The results show that the propagation distance could reach 4000 m,which overcome the limit of the Mie–Rayleigh scattering and absorption attenuation underwater.

Patient reported outcomes after implementation of an enhanced depth of focus intraocular lens with low postoperative myopia

Background:Enhanced depth-of-focus intraocular lenses(EDOF IOL)have filled the gap between monofocal and multifocal intraocular implants with optical qualities of monofocal lenses and usually minor dysphotopsias typical for multifocal lenses.The purpose of this study was to evaluate visual outcomes after bilateral implantation of a new EDOF IOL in patients with requirements for perfect near and intermediate vision.Methods:The study included 15 patients(29 eyes as one was amblyopic)with bilateral implantation of LUXSMART EDOF IOL(Bausch&Lomb)with a targeted myopia(between-0.25 and-0.50D)in both eyes.Monocular corrected and uncorrected visual acuity for far,intermediate and near as well as refractive outcomes were evaluated at 1,3,6 and 12 months after the surgery.Additionally,binocular visual acuity,contrast sensitivity and defocus curve were measured at the final follow-up visit.At 12 months’visit patients completed a questionnaire evaluating patient satisfaction,spectacle independence and presence of dysphotopsias.Results:Binocular uncorrected visual acuities at 12 month’s visit were 0.13±0.16,0.06±0.08,0.07±0.09 and 0.15±0.09 logMAR for far distance,80 cm,66 cm and 40 cm respectively.Corrected binocular visual acuities at 12 months were 0.00±0.00,0.05±0.07,0.05±0.06,0.13±0.16 respectively for distance,80 cm,66 cm and 40 cm.Automated refraction spherical equivalent at 12 months’visit stood at-0.70±0.48D,which was 0.46D less than calculated biometric target,however spherical equivalent of subjective refraction at 12 months equaled–0.49±0.46D,which was closer to preoperative biometric target.Defocus curve had gentle shape without peaks typical for monofocal IOLs.Binocular contrast sensitivity results were superior to average results for that age group and equaled 1.78±0.16 logMAR without correction and 1.81±0.13 logMAR with correction.Spectacle independence for near and intermediate distances was achieved in all patients and for far distance in 73.3%of patients.Burdensome dysphotopsias were not reported in any case.Conclusions:EDOF IOLs targeted bilaterally at low myopia can provide excellent near and intermediate visual acuity and independence of any optical correction in majority of cases.This approach can be used in selected patients who are focused on stationary activities.

Generation of X-ray vortex with ultra-long depth of focus using axial line-focused spiral zone plates

We propose axial line-focused spiral zone plates （ALFSZPs） for generating tightly focused X-ray vortex beams with ultra-long depth of focus （DOF） along the propagation direction. In this typical design, compared with the conventional spiral zone plates （SZPs） under the same numerical aperture （NA）, the DOF of ALFSZPs has been extended to an ultra-length by optimizing the corresponding parameters. Besides, it also exhibits lower side lobes and smaller dark cores in the whole focus volume. The diameters of dark cores increase as the topological charge value increases.

Model and optimization of ultrasonic phased array parameters

Beam focusing is one of the unique characteristics of ultrasonic phased array compared with conventional ultrasound.On the basis of two-dimensional radiated sound field of phased array,the three-dimensional radiated sound field was simulated in the paper,and then the effect of different frequencies,different number of array elements and different element spacings on focal spot,the depth of focus and the effect on horizontal and vertical resolution were analyzed.The optimal results of transducer parameters have certain reference value for the design of phased array probe.

Simple PSF based method for pupil phase mask’s optimization in wavefront coding system

By applying the wavefront coding technique to an optical system, the depth of focus can be greatly increased. Several complicated methods, such as Fisher Information based method, have already been taken to optimize for the best pupil phase mask in ideal condition. Here one simple point spread function (PSF) based method with only the standard deviation method used to evaluate the PSF stability over the depth of focus is taken to optimize for the best coefficients of pupil phase mask in practical optical systems. Results of imaging simulations for optical systems with and without pupil phase mask are presented, and the sharpness of image is calculated for comparison. The optimized results showed better and much more stable imaging quality over the original system without changing the position of the image plane.

Clinical outcomes of combined versus separate carbachol and brimonidine drops in correcting presbyopia

Background:To test and compare in a masked fashion the efficacy of using a parasympathomimetic drug(3%carbachol)and an alpha-2 agonist(0.2%brimonidine)in both combined and separate forms to create optically beneficial miosis to pharmacologically improve vision in presbyopia.Methods:A prospective,double-masked,randomized,controlled clinical trial was conducted.Ten naturally emmetropic and presbyopic subjects between 42 and 58 years old with uncorrected distance visual acuity of at least 20/20 in both eyes without additional ocular pathology were eligible for inclusion.All subjects received 3%carbachol and 0.2%brimonidine in both combined and separate forms,3%carbachol alone and 0.2%brimonidine(control)alone in their non-dominant eye in a crossover manner with one week washout between tests.The subjects’pupil sizes and both near and distance visual acuities will be evaluated pre-and post-treatment at 1,2,4,and 8 h,by a masked examiner at the same room illumination.Results:Statistically significant improvement in mean near visual acuity(NVA)was achieved in all subjects who received combined 3%carbachol and 0.2% brimonidine in the same formula compared with those who received separate forms or carbachol alone or brimonidine alone(P<0.0001).Conclusion:Based on the data,the combined solution demonstrated greater efficacy than the other solutions that were tested.Improving the depth of focus by making the pupil small caused statistically significant improvement in near visual acuity,with no change in binocular distance vision.Trial registration:ACTRN12616001565437.Registered 11 November 2016.

Retinal image quality with multifocal,EDoF,and accommodative intraocular lenses as studied by pyramidal aberrometry

Background:To study and compare the clinical optical image quality following implantation with different premium IOLs by analysing the point spread function(PSF)Strehl ratio using a pyramidal wavefront sensor(PWS)-based aberrometer.Methods:This study included 194 eyes implanted with:(a)19 AcrySof SA60AT(control group);(b)19 Miniwell;(c)24 LENTIS Mplus LS-313 MF30;(d)33 LENTIS Mplus LS-313 MF15;(e)17 AkkoLens Lumina;(f)31 AT LISA Tri 839MP;(g)20 Precizon Presbyopic;(h)20 AcrySof IQ PanOptix;(i)11 Tecnis Eyhance.Main outcome measures were PSF Strehl ratio,PSF Strehl ratio excluding second-order aberrations(PSFw2),total root mean square(RMS),low-order aberration(LOA)and high-order aberration(HOA)RMS measured by PWS aberrometer.Results:AT LISA Tri had the highest PSFw2 Strehl ratio at both 3.0-and 4.0-mm pupil size(0.52±0.14 and 0.31±0.10;P<0.05),followed by SA60AT(0.41±0.11 and 0.28±0.07)and PanOptix(0.4±0.07 and 0.26±0.04).AT LISA Tri was found to provide a significantly better retinal image quality than PanOptix at both 3.0 mm(P<0.0001)and 4.0 mm(P=0.004).Mplus MF15 was found to be significantly better than Mplus MF30 at both 3.0 mm(P<0.0001)and 4.0 mm(P=0.002).Total RMS,LOA RMS,HOA RMS,PSF Strehl ratio and PSFw2 varied significantly between the studied groups(P<0.001).Conclusions:Far distance clinical image quality parameters measured by PWS aberrometer differed significantly according to the technology of the implanted lens.AT LISA Tri,SA60AT and PanOptix showed the highest values of far distance retinal image quality,while the lowest PSFw2 Strehl ratios were displayed by Miniwell,Mplus MF30 and Precizon Presbyopic.

Retinal image quality with multifocal, EDoF, and accommodative intraocular lenses as studied by pyramidal aberrometry

BackgroundTo study and compare the clinical optical image quality following implantation with different premium IOLs by analysing the point spread function (PSF) Strehl ratio using a pyramidal wavefront sensor (PWS)-based aberrometer.MethodsThis study included 194 eyes implanted with: (a) 19 AcrySof SA60AT (control group);(b) 19 Miniwell;(c) 24 LENTIS Mplus LS-313 MF30;(d) 33 LENTIS Mplus LS-313 MF15;(e) 17 AkkoLens Lumina;(f) 31 AT LISA Tri 839MP;(g) 20 Precizon Presbyopic;(h) 20 AcrySof IQ PanOptix;(i) 11 Tecnis Eyhance. Main outcome measures were PSF Strehl ratio, PSF Strehl ratio excluding second-order aberrations (PSFw2), total root mean square (RMS), low-order aberration (LOA) and high-order aberration (HOA) RMS measured by PWS aberrometer.ResultsAT LISA Tri had the highest PSFw2 Strehl ratio at both 3.0- and 4.0-mm pupil size (0.52 ± 0.14 and 0.31 ± 0.10;P < 0.05), followed by SA60AT (0.41 ± 0.11 and 0.28 ± 0.07) and PanOptix (0.4 ± 0.07 and 0.26 ± 0.04). AT LISA Tri was found to provide a significantly better retinal image quality than PanOptix at both 3.0 mm (P < 0.0001) and 4.0 mm (P = 0.004). Mplus MF15 was found to be significantly better than Mplus MF30 at both 3.0 mm (P < 0.0001) and 4.0 mm (P = 0.002). Total RMS, LOA RMS, HOA RMS, PSF Strehl ratio and PSFw2 varied significantly between the studied groups (P < 0.001).ConclusionsFar distance clinical image quality parameters measured by PWS aberrometer differed significantly according to the technology of the implanted lens. AT LISA Tri, SA60AT and PanOptix showed the highest values of far distance retinal image quality, while the lowest PSFw2 Strehl ratios were displayed by Miniwell, Mplus MF30 and Precizon Presbyopic.

Constructing ultra-long focal fields via tightly focused Bessel beams

We numerically demonstrate that the tight focusing of Bessel beams can generate focal fields with an ultra-long depth of focus(DOF).The ultra-long focal field can be controlled by appropriately regulating the order of the Bessel function and the polarization.An optical needle and an optical dark channel with nearly 100λDOF are generated.The optical needle has a DOF of~104.9λand a super-diffraction-limited focal spot with the size of 0.19λ^(2).The dark channel has a full-width at halfmaximum of~0.346λand a DOF of~103.8λ.Furthermore,the oscillating focal field with an ultra-long DOF can be also generated by merely changing the order of the input Bessel beam.Our results are expected to contribute to potential applications in optical tweezers,atom guidance and capture,and laser processing.

Overlay mark optimization for thick-film resist overlay metrology

For thick resist implant layers,such as a high voltage P well and a deep N well,systematic and uncorrectable overlay residues brought about by the tapered resist profiles were found.It was found that the tapered profile is closely related to the pattern density.Potential solutions of the manufacturing problem include hardening the film solidness or balancing the exposure density.In this paper,instead of focusing on the process change methodology,we intend to solve the issue of the overlay metrology error from the perspective of the overlay mark design.Based on the comparison of the overlay performances between the proposed overlay mark and the original design,it is shown that the optimized overlay mark target achieves better performance in terms of profiles,dynamic precision,tool induced shift（TIS）,and residues.Furthermore,five types of overlay marks with dummy bars are studied,and a recommendation for the overlay marks is given.