Optical Lens System Research Articles

Endoscopic imaging of Cerenkov luminescence

We demonstrate feasibility of endoscopic imaging of Cerenkov light originated when charged nuclear particles, emitted from radionuclides, travel through a biological tissue of living subjects at superluminal velocity. The endoscopy imaging system consists of conventional optical fiber bundle/ clinical endoscopes, an optical imaging lens system, and a sensitive low-noise charge coupled device (CCD) camera. Our systematic studies using phantom samples show that Cerenkov light from as low as 1 µCi of radioactivity emitted from 18F-Fluorodeoxyglucose (FDG) can be coupled and transmitted through conventional optical fibers and endoscopes. In vivo imaging experiments with tumor bearing mice, intravenously administered with 18F-FDG, further demonstrated that Cerenkov luminescence endoscopy is a promising new tool in the field of endoscopic molecular imaging.

Analysis and parametric synthesis of the optical systems of a mirror–lens concentric objective

This paper analyzes the aberrational properties of mirror and mirror–lens optical systems consisting of the concentric surfaces of the objective and presents a method of parametrically synthesizing them.

Clinical characteristics and treatment outcomes of aggressive posterior retinopathy of prematurity

Objective To observe the clinical characteristics and treatment outcomes of aggressive posterior retinopathy of prematurity(AP-ROP).Methods Thirty-five eyes (18 patients) diagnosed with AP-ROP were studied from January 2006 to January 2011.All the patients were examined by 28 D optical lens,sclera compressor and wide-angle digital retinal imaging system (RetCam Ⅱ ).Laser photocoagulation with 532 nm wavelength using binocular indirect ophthalmoscope was used in all the infants within 12 hours after confirmed diagnosis. Thirteen eyes (37.1％) progressed to retinal detachment after laser photocoagulations were surgically treated,while 22 eyes (62.9 ％) underwent laser photocoagulation alone.Follow-up ranged from 6 months to 5 years,with a mean of 23.5 months.Results All AP-ROP lesions are located in zone 1 and posterior zone 2,with substantial dilated and tortuous retinal vessels.It is difficult to distinguish between the retinal vein and small arteries.There are shunts from vessel to vessel within the retina and no clear boundary between the vascularized and non-vascularized retina.Neovascularization lesions are flat and hard to be identified.There are no demarcation ridges.After laser treatment,22 eyes achieved good outcomes.Among 13 eyes who received vitrectomy,8 eyes achieved retinal reattachment after surgery,while 5 eyes developed total retinal detachment.Conclusion AP-ROP has specific clinical manifestations.Timely laser photocoagulation and early surgical treatment is necessary for AP-ROP. Key words: Retinopathy of prematurity/therapy; Laser coagulation; Vitrectomy

Hyperlenses and metalenses for far-field super-resolution imaging

The resolution of conventional optical lens systems is always hampered by the diffraction limit. Recent developments in artificial metamaterials provide new avenues to build hyperlenses and metalenses that are able to image beyond the diffraction limit. Hyperlenses project super-resolution information to the far field through a magnification mechanism, whereas metalenses not only super-resolve subwavelength details but also enable optical Fourier transforms. Recently, there have been numerous designs for hyperlenses and metalenses, bringing fresh theoretical and experimental advances, though future directions and challenges remain to be overcome.

Evaluation of the Truview™ EVO2 laryngoscope for nasotracheal intubation

Background:The Truview™ EVO2 laryngoscope, with its unique optical lens system and blade tip angulation, has proved its usefulness in providing adequate laryngeal exposure and intubation via the oral route. However, the same has not been evaluated for nasotracheal intubation.Aim:We evaluated the suitability of the Truview™ EVO2 laryngoscope for nasotracheal intubation.Methods:Fifty ASA grade I and II elective surgical patients were studied. Patients aged below 15 years or having difficult airway were excluded. Under standard anesthesia protocol, nasotracheal intubation was performed using a Truview™ EVO2 laryngoscope and, in cases of inability to complete intubation in three attempts, the Macintosh laryngoscope was used. Time taken for intubation, use of Magill's forceps and need for optimization maneuvers were noted. The primary outcome was percentage of successful intubation, while hemodynamic changes and duration of intubation were taken as secondary outcomes.Results:Majority (94%) could be intubated successfully with the Truview™ EVO2 laryngoscope. Average time taken for intubation was 50.1 s. The hemodynamic changes were not clinically significant. Regression analysis revealed lack of association between duration of intubation and hemodynamic changes. There were no serious complications.Conclusion:The Truview™ EVO2 laryngoscope is a useful tool in performing nasotracheal intubation, ensuring a high level of success rate among patients with normal airway anatomy.

Applied Research on the Electric Wet Effect in Optical System Design

In the past half century, the camera industry has developed very rapidly, which drove the optical lens and optical zoom technology to make great progress. The zoom lens’ technology principle of current mainstream optical zoom lens system is achieved by adjusting the relative position of the lens, objects and the focus. This paper takes the double-liquid zoom lens based on electric wet effect as the basis , the new zoom optical system is designed to achieve motor control without mechanical movement, then the vision correction is designed by using liquid lens, such as the correction of myopia and hyperopia, which can automatically identify the eyes degrees of myopia and hyperopia, avoid frequent replacement lens steps when optometry is done for eyes.

High Coupling Efficiency Optical Triplexer Module for 10G-EPON OLT Transceiver

The optical triplexer module, which consists of a 10.3-Gb/s transmitter [electroabsorption modulator integrated laser diode (EA-LD)], a 1.25-Gb/s transmitter (distributed feedback (DFB)-LD), and a 10.3-Gb/s/1.25-Gb/s dual-rate receiver [avalanche photodiode (APD)], has been developed for 10-Gb Ethernet passive optical network (10G-EPON) optical line terminal (OLT) transceiver. We have adopted a newly developed three lens optical system to accomplish high coupling efficiencies of two LDs as -2.84 and -1.65 dB. Moreover, we have adopted dual-rate preamp IC and high responsivity APD more than 0.78 A/W, and realized high receiver sensitivity of - 30.7 dBm for 10.3 Gb/s and - 35.7 dBm for 1.25 Gb/s. The triplexer module fully accomplishes IEEE802.3av PR30 standard specification with fair margin in a small package.

Prognostic Indicators and Outcome Measures for Surgical Removal of Symptomatic Nonadvanced Cataract

To report changes in perceived visual functioning after surgery for symptomatic cataract with preoperative corrected distance visual acuity [CDVA] of 0.4 logMAR or better (Snellen equivalent, 20/50) and to investigate the relationship between any observed changes and preoperative physical characteristics and psychophysical consequences of the lens opacity and any changes in psychophysical findings after the procedure. Eighty-five patients with cataract completed a validated questionnaire concerning functional vision satisfaction and a series of visual performance assessments before and 2 months after cataract surgery. The lens optical density and Lens Opacities Classification System III score of the cataract were recorded. Correlations between changes in the Rasch-analyzed questionnaire score and changes in visual performance after cataract surgery, as well as preoperative psychophysical measures, lens optical density, and Lens Opacities Classification System III score, were determined. The mean (SD) questionnaire score improved from 2.15 (0.36) to 1.54 (0.41) (P < .001). The preoperative questionnaire score (r = -0.44), preoperative mesopic glare disability [GD] (at 1.5 cycles per degree [cpd] [r = 0.34] and 3.0 cpd [r = 0.27]), and preoperative photopic GD (at 1.5 cpd [r = 0.24] and 3.0 cpd [r = 0.30]) showed statistically significant correlations with perceived improvements in visual functioning after surgery (P < .05). Changes in perceived visual functioning correlated significantly with changes in mesopic GD (at 1.5 cpd [r = -0.43] and 3.0 cpd [r = -0.28]; P < .05) and photopic GD (at 1.5 cpd [r = -0.24] and 3.0 cpd [r = -0.39]; P < .05). Neither preoperative CDVA nor change in CDVA after surgery correlated significantly with perceived improvement in visual functioning after the procedure (P > .05 for both). Psychophysical tests alternative to CDVA better represent improvements in self-reported visual functioning following removal of symptomatic nonadvanced cataract.

Antireflection/antifogging coatings based on nanoporous films derived from layered double hydroxide

Multifunctional mixed metal oxide (MMO) thin films on quartz substrates have been fabricated by layer-by-layer assembly of layered double hydroxide (LDH) nanoparticles and poly(sodium styrene 4-sulfonate) (PSS) followed by calcination, which exhibited properties of both antireflection (AR) and antifogging (AF). The AR and AF performances are related to the low refractive index and superhydrophilicity originating from the nanoporous structure. The influences of deposition cycle, LDH particle size and calcination temperature on AR and AF behavior were thoroughly studied. A maximum transmittance of 98.7% at 650 nm and a minimum time of 0.2 s for a droplet to spread flat (water contact angle ∼0°) were achieved with LDH particle size of 110 nm, 10 cycles of deposition and calcination temperature of 450 °C. Therefore, this work provides a facile approach for the fabrication of multifunctional coatings, which can be potentially used in photovoltaic devices, optical lens and underwater imaging systems.

Single Camera System for Multi-Parametric Fluorescence Imaging of the Heart

Optical mapping has become a typical method in cardiac electrophysiology. A single parameter is typically mapped, and recently dual mapping systems have been reported that record fluorescence signal of membrane potential and intracellular calcium using two cameras and a dichroic mirror. There are additional pairs of cardiac parameters measured by dual mapping system. However, the method to measure more than three parameters does not exist. To exploit the full potential of fluorescence imaging, an innovative method to measure multiple, more than three parameters is needed. In this study, we present new optical mapping system which records multiple, potentially more than three parameters using a single camera. The system consists of one camera, custom optical lens system, and filter wheel. The optical lens system is designed to focus the fluorescence light at filter position, and form an image on camera’s CMOS sensor. Filter wheel is rotated by a motor, which allows filter switching corresponding with needed wavelength. The camera exposure and filter switching are synchronized by phase locked loop techniques. We validated system performance by simple experiments; lens resolution, quantity of light, and synchronization. Using this system, we observed membrane potential and intracellular calcium in Langendorff perfused rabbit heart.

Investigation of Electric Discharge Sound in Atmospheric Pressure Plasma Using Optical Wave Microphone

AbstractThe light diffraction technique, which we call the “Optical Wave Microphone (OWM)” technique, is an effective sensing method to detect the sound and is flexible for practical uses as it involves only a simple optical lens system. This technique is also very useful to detect the sound wave without disturbing the sound field. Moreover, OWM can be used for sound field visualization by computerized tomography (CT) because the ultrasmall modulation by the sound field is integrated along the laser beam path. The characteristics of the coplanar DBD (Dielectric Barrier Discharge) operated in air is investigated. Applied voltage, current and the electrical discharge sound of coplanar DBD are measured, and examined the relationship between the micro discharge and the acoustic properties. We expect that understanding of acoustic properties gives more details of electric discharges. These are the first experiments to verify the feasibility of the OWM-CT method for the visualization of the sound field of DBD discharge.

Bionic soft crystalline lens materials for MEMs applications based on self-assembling amphiphilic block copolymer/nanoparticle hybrids

In this study, a biomimetic crystalline lens with properties that combine the softness of a hydrogel comparable to that of a human lens for adjustable focus and the property for image aberration correction with gradient refractive index (GRIN) was developed by the self-organization of an amphiphilic block copolymer blended with high refractive index titanium nanoparticles (TiO2). The hydrogel lens was prepared by using a thermally responsive poly(ethylene oxide)–poly(propylene oxide)–poly(ethylene oxide) (PPO–PEO–PPO) triblock copolymer (Poloxamer 407) with the lower-critical solution temperature (LCST) property that can be injectable into the eye capsule as a liquid below its LCST and solidifies as a soft gel above the LCST at the human body temperature. By chemical modification of the triblock copolymer with double bonds on its chain-ends (Poloxamer 407A), the soft lens network can be made by using UV crosslinking of the hydrogel. To further increase the refractive index (RI) of the hydrogel lens network and to match its RI to that of the human lens (=1.41), highly visible-light transparent titanium dioxide (TiO2) nanoparticles were introduced into the hydrogel lens network. To create a biomimetic GRIN lens as in the human’s eyes, an electric field method was also used to induce an axial diffusion of TiO2 nanoparticles from the center of the lens where TiO2 nanoparticles were first injected to the edge. The above method demonstrates the potential to use the hydrogel/nanoparticle hybrid as an injectable replacement for a soft optical lens system with an adjustable focus for future MEMs application.

Configuration and installation design of optical diagnostic systems on KSTAR

The optical diagnostic system of KSTAR consists of visible diagnostics including toroidal and poloidal Hα monitors, a visible survey spectrometer, and filterscopes. A re-entrant cassette made of stainless steel, containing five optical quartz windows has been developed to allow easy access of the visible diagnostics to the plasma. The configuration and manufacturing design of the diagnostic cassette and the installation of optical diagnostic systems within the cassette are described. The structural and thermal analysis of the diagnostic cassette and in situ calibration of optical diagnostics have also been performed. The optical lens system showed good image quality by spot diagram analysis.

Human-competitive results produced by genetic programming

Genetic programming has now been used to produce at least 76 instances of results that are competitive with human-produced results. These human-competitive results come from a wide variety of fields, including quantum computing circuits, analog electrical circuits, antennas, mechanical systems, controllers, game playing, finite algebras, photonic systems, image recognition, optical lens systems, mathematical algorithms, cellular automata rules, bioinformatics, sorting networks, robotics, assembly code generation, software repair, scheduling, communication protocols, symbolic regression, reverse engineering, and empirical model discovery. This paper observes that, despite considerable variation in the techniques employed by the various researchers and research groups that produced these human-competitive results, many of the results share several common features. Many of the results were achieved by using a developmental process and by using native representations regularly used by engineers in the fields involved. The best individual in the initial generation of the run of genetic programming often contains only a small number of operative parts. Most of the results that duplicated the functionality of previously issued patents were novel solutions, not infringing solutions. In addition, the production of human-competitive results, as well as the increased intricacy of the results, are broadly correlated to increased availability of computing power tracked by Moore’s law. The paper ends by predicting that the increased availability of computing power (through both parallel computing and Moore’s law) should result in the production, in the future, of an increasing flow of human-competitive results, as well as more intricate and impressive results.

折射/衍射红外鱼眼镜头光学系统设计

The optical design and properties of fish-eye lens are discussed.A refractive/diffractive IR fisheye lens optical system is presented,whose operating wavelength range is 8 to12 μm,and full field of view is up to 240°.The structure of optical system is reversed telephoto lens,and this type of hyper-wide angle lens can balance the off-axis aberrations against the evenness of marginal image illuminance at its image plane very wel1.The results show that the system has the advantages of simplicity,compactness and long back working distance.Its imaging quality is very well,so that its modulated transferfunction value is higher than 0.5 when cutoff frequency at the 11 lines/mm.

Simple and efficient scanning tunneling luminescence detection at low-temperature

We have designed and built an optical system to collect light that is generated in the tunneling region of a low-temperature scanning tunneling microscope. The optical system consists of an in situ lens placed approximately 1.5 cm from the tunneling region and an ex situ optical lens system to analyze the emitted light, for instance, by directing the light into a spectrometer. As a demonstration, we measured tip induced photoluminescence spectra of a gold surface. Furthermore, we demonstrate that we can simultaneously record scanning tunneling microscope induced luminescence and topography of the surface both with atomic resolution.

Fabrication and characterization of optofluidic flexible meniscus–biconvex lens system

This paper presents a novel optofluidic flexible meniscus–biconvex lens system. Using the developed flexible lens module with uniquely quadratic-curve-dominated meniscus and biconvex lenses, the focus of the lens system can be tuned by varying the applied fluid pressures. The innovative lens fabrication method is described and the manufactured lenses with different processing parameters are characterized. These curved flexible lenses display non-spherical shapes under exertion of uniformly distributed liquid pressures. Through the experimental setup of assembled optical lens system with a fluid controlled mechanism, the resulting images are captured. A change in focal length of five times (19.1–80.8 cm) is demonstrated and the focal length shows a quadratic relation to the applied pressure (0–5 kPa). Besides, the distortion can be kept below 5% and relative illumination remains above 0.74 through the analysis of ZEMAX simulation over a 0–5 kPa range of liquid pressure. Thus, the resulting images from the developed lens module not only show good contrast and clear quality, but also relatively little distortion, and good relative illumination results are found while tuning the focus.

Cell culture device using spatial light modulator

Spatial light modulator is introduced for cell culturing and related illumination experiment. Two kinds of designs were used. The first type put the cell along with the bio-medium directly on top of the analyzer of the microdisplay and set a cover glass on it to retain the medium environment, which turned the microdisplay into a bio-container. The second type introduced an optical lens system placed below the spatial light modulator to focus the light spots on specific position. Details of the advantages and drawbacks for the two different approaches are discussed, and the human melanocyte cell (HMC) is introduced to prove the feasibility of the concept. Results indicate that the second type is much more suitable than the first for precision required application.

不同光聚焦状态的光击穿声辐射特性

不同光聚焦状态的光击穿声辐射特性

Photographic diagnosis of crystalline silicon solar cells utilizing electroluminescence

The photographic surveying of electroluminescence (EL) under forward bias was proved to be a powerful diagnostic tool for investigating not only the material properties but also process induced deficiencies visually in silicon (Si) solar cells. Under forward bias condition, solar cells emit infrared light (wavelength around 1000 to 1200 nm) whose intensity reflects the number of minority carriers in base layers. Thus, all the causes that affect the carrier density can be detected, i.e., the minority carrier diffusion length (or in other words, lifetime), recombination velocity at surfaces and interfaces, etc. (intrinsic material properties), and wafer breakage and electrode breakdown, etc. (extrinsic defects). The EL intensity distribution can be captured by Si CCD camera in less than 1 s, and the detection area simply depends upon the optical lens system suitable to the wide range of 1 cm–1.5 m. This fast and precise technique is superior to the conventional scanning method such as the laser beam induced current (LBIC) method.