Mirror Lens Research Articles

Intraocular Pressure While Using Gonioscopy, SLT, and Laser Iridotomy Lenses: An Ex Vivo Study.

The purpose of this study was to measure intraocular pressure (IOP) elevation while applying standard gonioscopy, selective laser trabeculoplasty (SLT), and laser iridotomy procedural lenses. Twelve cadaver eyes were mounted to a custom apparatus and cannulated with a pressure transducer which measured IOP. The apparatus was mounted to a load cell which measured the force on the eye. Six ophthalmologists performed simulated gonioscopy (Sussman 4 mirror lens), SLT (Latina lens), and laser iridotomy (Abraham lens) while a computer recorded IOP (mm Hg) and force (grams). The main outcome measures were IOP and force applied to the eye globe during ophthalmic diagnostics and procedures. The average IOP's during gonioscopy, SLT, and laser iridotomy were 43.2 ± 16.9 mm Hg, 39.8 ± 9.9 mm Hg, and 42.7 ± 12.6 mm Hg, respectively. The mean force on the eye for the Sussman, Latina, and Abraham lens was 40.3 ± 26.4 grams, 66.7 ± 29.8 grams, and 65.5 ± 35.9 grams, respectively. The average force applied to the eye by the Sussman lens was significantly lower than both the Latina lens (P = 0.0008) and the Abraham lens (P = 0.001). During gonioscopy indentation, IOP elevated on average to 80.5 ± 22.6 mm Hg. During simulated laser iridotomy tamponade, IOP elevated on average to 82.3 ± 27.2 mm Hg. In cadaver eyes, the use of standard ophthalmic procedural lenses elevated IOP by approximately 20 mm Hg above baseline.

Improving energy efficiency: a highly efficient coaxial design for a laser ranging system with a splicing lens.

Light detection and ranging (LiDAR) systems have made significant contributions in different applications. The laser ranging (LR) system is one of the core components of LiDARs. However, existing coaxial LR systems suffer from low energy efficiency due to obstruction of the reflection mirror. In this study, we carefully design a laser transmitter and receiver subsystem and consequently propose a highly energy-efficient coaxial design for a time of light-based LR system, where a perforated mirror and splicing lens account for the promotion of energy efficiency. The small hole in the perforated mirror is located on the object focus of the focusing lens to ensure the laser beam will pass through the perforated mirror without obstructions. The ring-shape splicing lens, consisting of two parts, is used for laser collimation and laser reception simultaneously. Laboratory experiments proved that the proposed design eliminates the complex calibration process for noncoaxial LR systems while reaching a comparable energy efficiency, which is higher than 98%. We believe it is an economical yet efficient way to promote the energy efficiency of coaxial LR systems.

High-aperture EUV microscope using multilayer mirrors and a 3D reconstruction algorithm based on z-tomography.

The article is devoted to the development of an EUV microscope using a wavelength of 13.84 nm. Due to the use of a mirror lens with a large numerical aperture, NA = 0.27, and a short depth of focus, it has been possible to carry out z-tomography of bio-samples for the first time with this type of microscope. A 3D image was reconstructed, and a pixel resolution of 140 nm was obtained. A new simple algorithm for the 3D reconstruction of absorption images from z-tomography data has been proposed that takes into account lens aberrations and a point spread function. The algorithm reduces the inverse absorption task to the corresponding well-studied task of fluorescence microscopy, with an error of 10% for cells up to 10 µm thick.

Intraocular Pressure Control after Trabeculectomy: A Comparison of Mitomycin C and Bevacizumab

Objective: To analyze and compare the role of mitomycin C and bevacizumab in reducing the intraocular pressure post trabeculectomy. Study Design: Comparative analytical study Place and Duration of Study: Department of Ophthalmology, Indus Medical College, Tando Mohammad Khan from 1st October 2021 to 31st March 2022. Methodology: Sixty patients were enrolled. Patients were divided equally in two groups. Thirty patients were given mitomycin C in Group A while Group B were those 30 patients who were given bevacizumab in a randomized manner. All the cases underwent trabeculectomy and followed upto a year and results were compared. An examination using slit lamp biomicroscope was performed for thorough examination of anterior segments with intraocular pressure recording. Gonioscopy through Goldman-two mirror lens was conducted. Results: The mean age of the patients was 50.23±7.7 years with 41.6 % females and 58.3% males. The intraocular pressure was seen to be controlled in 23 patients at day 1 in Group A and 23 patients in group B. The comparative analysis of pre and post intraocular pressure after trabeculectomy has presented the significant reduction in Group A than Group B at day 1, 6th week as well as at 3rd month or 6th moth to a year. Conclusion: Mitomycin C as well as bevacizumab are highly effective in reducing intraocular pressure post trabeculectomy with mitomycin C being slightly better in efficacy than bevacizumab. Keywords: Intraocular pressure, Trabeculectomy, Effective, Efficacy

Beam-angle-scanning surface plasmon resonance sensor for rapid, high-precision sensing of refractive index and bio-molecules

Surface plasmon resonance (SPR) sensors are powerful tools for optical sensing of refractive index (RI) and bio-molecules due to their high sensitivity. In this article, we demonstrate a beam-angle-scanning SPR system using a combined galvanometer mirror and relay lens optics. Use of a photodetector in the galvanometer mirror scanning of the incident beam angle enables both high precision and rapid data acquisition. RI resolution of 2.306×10−5 refractive index unit (RIU) and RI accuracy of 8.984×10−5 RIU were achieved at a data acquisition rate of 100 Hz. Furthermore, we performed real-time monitoring of the avidin-biotin antigen-antibody reaction. The results show the high potential of this beam-angle-scanning SPR system.

Synthesis of Bifocal Mirror–Lens Cylindrical System with Minimum Aberrations

Synthesis of Bifocal Mirror–Lens Cylindrical System with Minimum Aberrations

Wide-angle concentric mirror lens objective

A new optical system of a wide-angle concentric isochromatic mirror–lens objective with a real image is presented and analyzed. The conditions for its isochromatic correction are obtained. The practical implementation of the objective is described.

P‐54: Student Poster: Collimation and Homogenization of Light for High Illuminous LED Based System

To replicate the sunlight, some groups have used a mini lens array as an optical element to attain homogenization of light. However, the collimation of the light beam in compact settings is still a challenge. A light collimation and homogenization LED system is proposed using a parabolic mirror and mini lens array. The parabolic mirror ensures the collimation of the light beam, while the mini lens array secures the homogenization. We assembled and tested the results of the 2×2 array and 8×8 array models, which show a small divergence (6.72°) and good uniformity (uniformity coefficient is 67.4% and 45.7% respectively).

30‐1: Invited Paper: High Aspect Ratio OLED Microdisplay with Pin Mirror Lens for Small Form Factor AR Devices

In this paper, we developed the high aspect ratio color OLED microdisplay and combined with the pin mirror lens, providing a wide FoV AR device in a small form factor. The white OLED exhibited the luminance of 14,072 cd/m2 and current efficiency of 33.8 cd/A at 9 V. To reduce optical crosstalk, color filters were directly patterned on the chip. The high aspect ratio OLED microdisplay was then combined with the pin mirror lens, resulting in maximum horizontal FoV 46.6° at the lens thickness of 4 mm. By using such a simple display module, we successfully demonstrated the small form factor AR device.

High aspect ratio microdisplay and thin optical component for glass-like AR devices

Organic light-emitting diode (OLED) microdisplays have attracted much attention as displays for small form factor augmented reality (AR) devices. To realize glass-like thin and wide field of view (FoV) AR devices, we designed a display module with a high aspect ratio microdisplay and a thin optical component. For the high aspect ratio microdisplay, we developed the color OLED microdisplay with a 32:9 aspect ratio and a 0.8-inch diagonal ∼2,490-ppi CMOS backplane. To express color and reduce optical crosstalk, we fabricated the color filter (C/F) patterning directly on the white OLED. We also developed a pin mirror lens with 11 pin mirrors to improve the optical efficiency and quality with a thin lens. By combining the microdisplay with LetinAR’s pin mirror lens, we successfully demonstrated an AR device with a wide horizontal FoV of 46° but with a small form factor 4 mm lens.

Development of a time-resolved mirrorless scintillation detector.

PurposeWe developed a compact and lightweight time-resolved mirrorless scintillation detector (TRMLSD) employing image processing techniques and a convolutional neural network (CNN) for high-resolution two-dimensional (2D) dosimetry.MethodsThe TRMLSD comprises a camera and an inorganic scintillator plate without a mirror. The camera was installed at a certain angle from the horizontal plane to collect scintillation from the scintillator plate. The geometric distortion due to the absence of a mirror and camera lens was corrected using a projective transform. Variations in brightness due to the distance between the image sensor and each point on the scintillator plate and the inhomogeneity of the material constituting the scintillator were corrected using a 20.0 × 20.0 cm2 radiation field. Hot pixels were removed using a frame-based noise-reduction technique. Finally, a CNN-based 2D dose distribution deconvolution model was applied to compensate for the dose error in the penumbra region and a lack of backscatter. The linearity, reproducibility, dose rate dependency, and dose profile were tested for a 6 MV X-ray beam to verify dosimeter characteristics. Gamma analysis was performed for two simple and 10 clinical intensity-modulated radiation therapy (IMRT) plans.ResultsThe dose linearity with brightness ranging from 0.0 cGy to 200.0 cGy was 0.9998 (R-squared value), and the root-mean-square error value was 1.010. For five consecutive measurements, the reproducibility was within 3% error, and the dose rate dependency was within 1%. The depth dose distribution and lateral dose profile coincided with the ionization chamber data with a 1% mean error. In 2D dosimetry for IMRT plans, the mean gamma passing rates with a 3%/3 mm gamma criterion for the two simple and ten clinical IMRT plans were 96.77% and 95.75%, respectively.ConclusionThe verified accuracy and time-resolved characteristics of the dosimeter may be useful for the quality assurance of machines and patient-specific quality assurance for clinical step-and-shoot IMRT plans.

Юстировка зеркально-линзового объектива c эксцентрично расположенным зрачком для инфракрасного диапазона спектра

Юстировка зеркально-линзового объектива c эксцентрично расположенным зрачком для инфракрасного диапазона спектра

Subjective Evaluation of Defocus and Astigmatism Combinations Using Image Simulation in Presbyopes.

Image simulation is a useful and efficient tool to explore the impact of defocus and astigmatism combinations on visual acuity and image quality score when accommodation is taken into account. The goal of this experiment was to determine if a simulation is able to predict visual acuity and image quality score (IQS) with defocus and astigmatism combinations in presbyopes. We measured visual acuity and IQS in five defocus and astigmatism combinations in either real or simulated conditions. In real conditions, the subjects viewed a stimulus through an ophthalmic lens or a deformable mirror. In simulated conditions, subjects viewed images of the same stimulus with simulated blur. The amounts of defocus and astigmatism combinations of a progressive addition lens in near vision were generated through a static correction of the subject's aberrations. We simulated three levels of accommodation: subject could not accommodate (FOC0), subject could accommodate to the less hyperopic focal point (FOC1), or subject could accommodate to the circle of least confusion (FOC2). Visual acuity or IQS did not differ between mirror and progressive addition lens conditions. Visual acuity measured in real blur conditions differed significantly from that in FOC0 simulated blur condition but were similar to that in FOC1 and FOC2 simulated blur conditions. Image quality score obtained in real conditions were between scores measured with the FOC0 and FOC1 simulated conditions, suggesting that the subjects were able to produce a low level of accommodation. Accommodation may play a role when comparing optical and simulated defocus and astigmatism combinations. Presbyopic subjects are able to produce a low level of accommodation that may counterbalance a part of the deleterious effect of the astigmatism on image quality. Simulation remains a useful tool if the correct accommodation state is taken into account.

Detecting Minerals and Organics Relevant to Planetary Exploration Using a Compact Portable Remote Raman System at 122 Meters.

Raman spectroscopy is a technique that can detect and characterize a range of molecular compounds such as water, water ice, water-bearing minerals, and organics of particular interest to planetary science. The detection and characterization of these molecular compounds, which are indications of habitability on planetary bodies, have become an important goal for planetary exploration missions spanning the solar system. Using a compact portable remote Raman system consisting of a 532 nm neodymium-doped yttrium aluminum garnet- (Nd:YAG-) pulsed laser, a 3-in. (7.62 cm) diameter mirror lens and a compact spectrograph with a miniature intensified charge coupled device (mini-ICCD), we were able to detect water (H2O), water ice (H2O-ice), CO2-ice, hydrous minerals, organics, nitrates, and an amino acid from a remote distance of 122 m in natural lighting conditions. To the best of our knowledge, this is the longest remote Raman detection using a compact system. The development of this uniquely compact portable remote Raman system is applicable to a range of solar system exploration missions including stationary landers for ocean worlds and lunar exploration, as they provide unambiguous detection of compounds indicative of life as well as resources necessary for further human exploration.

12‐3: Organic Light‐emitting Diode Microdisplay with a 32:9 Aspect Ratio for Wide Field of View

Microdiplay is one of critical factors to determine the performance of AR glasses. A white OLED with tandem structure have been developed for OLED microdiplays. The device has driving voltage of 6.9 V for 1,000 cd/m2 and maximum current efficiency of 19.5 cd/A. Using developed white OLED structure, we have successfully demonstrated a white OLED microdisplay with a 32:9 aspect ratio. This large aspect ratio can be helpful for improving field of view of AR glasses using a pin mirror lens.

Evaluation of glaucoma cases with gonioscopy and optical coherence tomography

Glaucoma is the second leading cause of blindness in the adult population of India. Diagnosis and management depends on categorization of Glaucoma into open or closed angle. : To compare the accuracy of Gonioscopy and Anterior Segment Optical Coherence Tomography (ASOCT) in studying the structures of anterior chamber angle of the eye and find out the agreement between them in detecting angle closure. Cross -sectional observational study. The present study is a hospital based cross-sectional study of patients between 20 to 80 years of age with Glaucoma attending the outdoor patient department in a tertiary care government hospital (New civil hospital), Surat. Patients having Corneal Opacity, and anti-Glaucoma surgeries done were excluded. All diagnosed cases of Glaucoma were evaluated by Gonioscopy in the dark with a Goldman 3 mirror lens Gonioscope at high (16x) magnification for static assessment (without indentation). A narrow slit beam, 2mm* 1mm, was cast during Gonioscopy, avoiding direct illumination over the pupil. The angle in each quadrant was graded with the Shaffer grading system. Anterior Segment OCT was done by TOPCON 3D OCT-1 MAESTRO machine. Imaging was performed in dark room conditions. Patients were imaged gazing straight ahead. Imaging of a single meridional section of the Anterior Chamber Angle at superior, inferior, temporal and nasal quadrants were performed. Grading of Anterior Chamber Angles on AS-OCT is termed as Closed if there is no visualization of Scleral Spur and/or any degree of irido-trabecular contact. kappa value, sensitivity & specificity, positive & negative likelihood ratio. Total 50 Glaucoma patients were examined by Gonioscopy and AS OCT. Total number of Angles examined were 400. Total number of Angles closed on Gonioscopy were 136 (34%). Total number of Angles closed on AS OCT were 190 (47.5%). Agreement between Gonioscopy and AS OCT in detecting angle closure in all 4 quadrants was ‘Moderate to Good’ by Kappa Value.

Demarcation Laser Photocoagulation for Subclinical Retinal Detachment: Can Progression to Retinal Detachment Be Prevented?

Objectives:To describe results of demarcation laser photocoagulation in preventing progression of subclinical retinal detachment (SCRD).Materials and Methods:Twenty-one eyes of 20 patients with SCRD were included. All patients underwent a complete ophthalmological examination, spectral-domain optical coherence tomography, and color fundus photography. Ages at initial diagnosis ranged between 18 and 75 years (mean: 57.3±16.2 years). Patients followed for at least 6 months were included in the study. Periodic retinal examinations were performed over follow-up periods of 6-55 months using Goldmann three-mirror contact lens and sometimes semilunar mirror lens with scleral indentation.Results:Twelve patients (60%) were female, eight (40%) were male. The mean follow-up period was 24.3±15.2 months (6-55 months). Three (14.3%) eyes were pseudophakic. One patient was affected bilaterally, with both eyes each containing two separate areas of involvement. The SCRD was in the upper quadrant of 18 eyes (85.7%) and the lower quadrant in 3 eyes (14.3%), and was located in the temporal region 10 eyes (47.6%), the nasal quadrant in 4 eyes (19.1%), and in the upper quadrant (temporal-nasal) in 7 eyes (33.3%). Six eyes (28.6%) were found to have myopia greater than -3.0 diopters. Progression to clinical retinal detachment was observed in 4/21 SCRD eyes (19%). All eyes showing progression to clinical retinal detachment had >-3.0 diopter myopia and multiple retinal tears located in the upper quadrant.Conclusion:Demarcation laser photocoagulation should be kept in mind as a first-line treatment for eyes with SCRD. Laser photocoagulation is vital in preventing progression to rhegmatogenous retinal detachment in most patients. After this treatment, these patients should be followed closely.

Physical foundation of optical smart antenna based on metamaterial and lithium niobate

In this work we present the main physical foundations of optical antenna array. This antenna array is based on the mirror system and lens system. To provide the necessary phase shift we propose two kind of structures: based on litium neobate and on ferrite-garnet. The main analytical expressions describing system behaviour are found for the first time. The results of calculation of the lens system parameters in the program ZEMAX are presented also.

Focus-tunable micro-reflective lens: Design and fabrication feasibility with deformable micromirror

This paper presents a novel design and fabrication concept for a fully reflective architecture-based focus-tunable micromirror lens without translating constituent mirrors. The lens system consists of two mirror elements: a microelectromechanical-system varifocal spherically deformable convex micromirror and a fixed-focal spherical concave micromirror. After the fabrication and optical characterization of the two individual mirrors, they are vertically integrated 4 cm apart, with their own optical-axis alignment, for the realization of the lens system. The mirror lens system, comprising a 20-mm-diameter concave primary micromirror with a fixed focal length of 70.8 mm and 4-mm-diameter deformable convex secondary micromirror actuated by electromagnetic force as the driving component of the entire system, allows a focal-length tunability of ~74 mm via the application of an input controlling current of 0.8 A to the solenoid. The focusing performance of the realized micromirror lens system is evaluated. Despite speckle noise in the focused images, which possibly originates from the geometry of the mirror components, the varifocal micromirror lens is demonstrated to be feasible with regard to fully reflective and non-movable mirrors.

ФИЗИЧЕСКИЕ ОСНОВЫ ПОСТРОЕНИЯ УПРАВЛЯЕМОЙ ОПТИЧЕСКОЙ АНТЕННЫ НА ОСНОВЕ НИОБАТА ЛИТИЯ

The article highlights a promising direction for high-speed signal transmission in wireless optical communication systems, namely, the use of optical antennas. Unlike fiber-optic systems which are sufficiently advanced today, today only one patent and one work are performed to describe the optical antenna array, which describes the optical antenna array for transmitting the optical signal in telecommunication networks. An important task in creating the antenna is selecting intelligent material to control the radiation pattern. The main physical foundations of optical antenna array have been described. The antenna array is based on the mirror system and lens system. To provide the necessary phase shift, two kinds of structures are proposed: of lithium niobate and of ferrite-garnet. The main analytical expressions describing system behavior are found for the first time.