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Double-distance propagation of Gaussian beams passing through a tilted cat-eye optical lens in a turbulent atmosphere 被引量:2
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作者 赵延仲 孙华燕 宋丰华 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第4期301-309,共9页
By using the extended Huygens-Fresnel diffraction integral and the method of expanding the aperture function into a finite sum of complex Caussian functions, an approximate analytical formula of the double-distance pr... By using the extended Huygens-Fresnel diffraction integral and the method of expanding the aperture function into a finite sum of complex Caussian functions, an approximate analytical formula of the double-distance propagation for Caussian beam passing through a tilted cat-eye optical lens and going back along the entrance way in a turbulent atmosphere has been derived. Through numerical calculation, the effects of incidence angle, propagation distance, and structure constant on the propagation properties of a Gaussian beam in a turbulent atmosphere are studied. It is found that the incidence angle creates an unsymmetrical average intensity distribution pattern, while the propagation distance and the structure constant can each create a smooth and symmetrical average intensity distribution pattern. The average intensity peak gradually deviates from the centre, and the central average intensity value decreases quickly with the increase in incidence angle, while a larger structure constant can bring the average intensity peak back to the centre. 展开更多
关键词 cat-eye optical lens turbulent atmosphere Gaussian beams double-distance propagation
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Comparison of optical quality after implantable collamer lens implantation and wavefront-guided laser in situ keratomileusis 被引量:13
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作者 Hong-Ting Liu Zhou Zhou +8 位作者 Wu-Qiang Luo Wen-Jing He Owhofasa Agbedia Jiang-Xia Wang Jian-Zhong Huang Xin Gao Min Kong Min Li Li Li 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2018年第4期656-661,共6页
AIM: To compare the optical quality after implantation of implantable collamer lens(ICL) and wavefront-guided laser in situ keratomileusis(WG-LASIK).METHODS: The study included 40 eyes of 22 patients with myopia... AIM: To compare the optical quality after implantation of implantable collamer lens(ICL) and wavefront-guided laser in situ keratomileusis(WG-LASIK).METHODS: The study included 40 eyes of 22 patients with myopia who accepted ICL implantation and 40 eyes of 20 patients with myopia who received WG-LASIK. Before surgery and three months after surgery, the objective scattering index(OSI), the values of modulation transfer function(MTF) cutoff frequency, Strehl ratio, and the Optical Quality Analysis System(OQAS) values(OVs) were accessed. The higher order aberrations(HOAs) data including coma, trefoil, spherical, 2^(nd) astigmatism and tetrafoil were also obtained. For patients with pupil size 〈6 mm, HOAs data were analyzed for 4 mm-pupil diameter. For patients with pupil size ≥6 mm, HOAs data were calculated for 6 mm-pupil diameter. Visual acuity, refraction, pupil size and intraocular pressures were also recorded.RESULTS: In both ICL and WG-LASIK group, significant improvements in visual acuities were found postoperatively, with a significant reduction in spherical equivalent(P〈 0.001). After the ICL implantation, the OSI decreasedslightly from 2.34±1.92 to 2.24±1.18 with no statistical significance(P=0.62). While in WG-LASIK group, the OSI significantly increased from 0.68±0.43 preoperatively to 0.91±0.53 postoperatively(Wilcoxon signed ranks test, P=0.000). None of the mean MTF cutoff frequency, Strehl ratio, OVs showed statistically significant changes in both ICL and WG-LASIK groups. In the ICL group, there were no statistical differences in the total HOAs for either 4 mmpupil or 6 mm-pupil. In the WG-LASIK group, the HOA parameters increased significantly at 4 mm-pupil. The total ocular HOAs, coma, spherical and 2^(nd) astigmatism were 0.12±0.06, 0.06±0.03, 0.00±0.03, 0.02±0.01, respectively. After the operation, these values were increased into 0.16±0.07, 0.08±0.05,-0.04±0.04, 0.03±0.01 respectively(Wilcoxon signed ranks test, all P〈0.05). At 6 mm-pupil, the induction of total HOAs was not statistically significant in the WG-LASIK group. CONCLUSION: ICL implantation has a less disturbance to optical quality than WG-LASIK. The OQAS is a valuable complementary measurement to the wavefront aberrometers in evaluating the optical quality. 展开更多
关键词 optical quality implantable collamer lens wavefront-guided laser in situ keratomileusis
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Measuring Topological Charges of Optical Vortices with Multi-Singularity Using a Cylindrical Lens 被引量:1
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作者 彭宇 甘雪涛 +2 位作者 俱沛 王亚东 赵建林 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第2期56-59,共4页
We present a simple method to measure the topological charges of optical vortices with multiple singularities. Using a cylindrical lens, a vortex beam can decay into a light field distribution with multiple separated ... We present a simple method to measure the topological charges of optical vortices with multiple singularities. Using a cylindrical lens, a vortex beam can decay into a light field distribution with multiple separated dark holes, whose number just equals the topological charge of the input beam. This conclusion is then verified via experiments and numerical simulations of the propagation of vortex beams with multiple singulaxities. This method is also reliable to measure the topological charges of broadband vortex beams with different distributions of singularities, which does not resort to multiple beam interferometrie experiments. 展开更多
关键词 TC Measuring Topological Charges of optical Vortices with Multi-Singularity Using a Cylindrical lens
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Optics System Design of Microwave Imaging Reflectometry for the EAST Tokamak 被引量:1
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作者 朱逸伦 赵朕领 +3 位作者 仝丽 陈东旭 谢锦林 刘万东 《Plasma Science and Technology》 SCIE EI CAS CSCD 2016年第4期449-452,共4页
A front-end optics system has been developed for the EAST microwave imaging reflectometry for 2D density fluctuation measurement.Via the transmitter optics system,a combination of eight transmitter beams with independ... A front-end optics system has been developed for the EAST microwave imaging reflectometry for 2D density fluctuation measurement.Via the transmitter optics system,a combination of eight transmitter beams with independent frequencies is employed to illuminate wide poloidal regions on eight distinct cutoff layers.The receiver optics collect the reflected wavefront and project them onto the vertical detector array with 12 antennas.Utilizing optimized Field Curvature adjustment lenses in the receiver optics,the front-end optics system provides a flexible and perfect matching between the image plane and a specified cutoff layer in the plasma,which ensures the correct data interpretation of density fluctuation measurement. 展开更多
关键词 density measurement multi-dimension microwave diagnostic optics lens
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Optical system and lens design for Blu-ray disc optical pick-up 被引量:1
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作者 李莉华 潘龙法 马建设 《Chinese Optics Letters》 SCIE EI CAS CSCD 2008年第6期426-430,共5页
During the design process of Blu-ray disc optical pick-up (BD OPU), the optical system and the collimator lens design is especially important. This paper designs an optical system and some lenses for'the BD OPU, in... During the design process of Blu-ray disc optical pick-up (BD OPU), the optical system and the collimator lens design is especially important. This paper designs an optical system and some lenses for'the BD OPU, including collimator lens, beam shaping lens for laser beam shaping, and cylinder lens for signal detecting. In this OPU, we use a triplet lens to collimate the laser beam. At the same time, we build a series of assembly jigs to make sure that each lens can be put into the OPU basement properly. At last, we get the reading spot image and S-curve photo of OPU, which can be used to read Blu-ray disc (BD). 展开更多
关键词 Computer networks Design Laser beams optical collimators optical data processing optical devices optical instrument lenses optical systems PHOTOLITHOGRAPHY Process design Process engineering Soldered joints
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Precision glass molding: Toward an optimal fabrication of optical lenses 被引量:5
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作者 Liangchi ZHANG Weidong LIU 《Frontiers of Mechanical Engineering》 SCIE CSCD 2017年第1期3-17,共15页
It is costly and time consuming to use machining processes, such as grinding, polishing and lapping, to produce optical glass lenses with complex features. Precision glass molding (PGM) has thus been developed to re... It is costly and time consuming to use machining processes, such as grinding, polishing and lapping, to produce optical glass lenses with complex features. Precision glass molding (PGM) has thus been developed to realize an efficient manufacture of such optical components in a single step. However, PGM faces various technical challenges. For example, a PGM process must be carded out within the super-cooled region of optical glass above its glass transition temperature, in which the material has an unstable non-equilibrium structure. Within a narrow window of allowable tempera- ture variation, the glass viscosity can change from 10s to 10t2 Pa-s due to the kinetic fragility of the super-cooled liquid. This makes a PGM process sensitive to its molding temperature. In addition, because of the structural relaxa- tion in this temperature window, the atomic structure that governs the material properties is strongly dependent on time and thermal history. Such complexity often leads to residual stresses and shape distortion in a lens molded, causing unexpected changes in density and refractive index. This review will discuss some of the central issues in PGM processes and provide a method based on a manufacturing chain consideration from mold material selection, property and deformation characterization of optical glass to process optimization. The realization of such optimization is a necessary step for the Industry 4.0 of PGM. 展开更多
关键词 precision glass molding optical lens consti-tutive modeling optimization manufacturing chain Indus-try 4.0
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A novel technique for wireless optical communications with lenslet array processor 被引量:5
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作者 潘卫清 刘立人 +1 位作者 刘宏展 邓绍更 《Chinese Optics Letters》 SCIE EI CAS CSCD 2006年第5期265-267,共3页
A novel communication technique is proposed, which utilizes a set of mutually distinguishable optical patterns instead of convergent facula to transmit information. Then the capacity is increased by exploiting the opt... A novel communication technique is proposed, which utilizes a set of mutually distinguishable optical patterns instead of convergent facula to transmit information. Then the capacity is increased by exploiting the optical spatial bandwidth resources. At last, we experimentally demonstrate the proposed communication technique based on four 8 × 8 spatial pattern signals by using lenslet array processor. 展开更多
关键词 BANDWIDTH Channel capacity Communication channels (information theory) optical devices optical instrument lenses Wireless telecommunication systems
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Three-dimensional optical data storage using a solid immersion lens to focus a femtosecond laser pulse 被引量:1
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作者 贺锋涛 程光华 +6 位作者 冯晓强 张东玲 程昭 刘青 赵卫 陈国夫 侯洵 《Chinese Optics Letters》 SCIE EI CAS CSCD 2004年第7期423-425,共3页
A solid immersion lens (SIL) has been applied to the writing and reading of three-dimensional optical data storage in transparent materials. Using a SIL with n=1.516 to focus a 150-fs, 800-nm Tiisapphire laser, the 5-... A solid immersion lens (SIL) has been applied to the writing and reading of three-dimensional optical data storage in transparent materials. Using a SIL with n=1.516 to focus a 150-fs, 800-nm Tiisapphire laser, the 5-layer reading and writing of data are achieved in fused silica and polyethylene methacrylate at a density of 1.1×10 2 b/cm3. Some advantages of the employment of SIL have been discussed. 展开更多
关键词 FOCUSING Laser pulses optical instrument lenses SILICA Three dimensional
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A Meta-analysis on the clinical efficacy and safety of optic capture in pediatric cataract surgery 被引量:2
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作者 Hong-Wei Zhou Fang Zhou 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2016年第4期590-596,共7页
AIM: To evaluate the clinical efficacy and safety of optic capture in pediatric cataract surgery.·METHODS: Searches of peer-reviewed literature were conducted in Pub Med, Embase and the Cochrane Library. The se... AIM: To evaluate the clinical efficacy and safety of optic capture in pediatric cataract surgery.·METHODS: Searches of peer-reviewed literature were conducted in Pub Med, Embase and the Cochrane Library. The search terms were "optic capture" and "cataract". The retrieval period ended in December 2014.Relevant randomized controlled trials(RCTs), case-control studies and cohort studies were included. Meta-analyses were performed. Pooled weighted mean differences and risk ratios with 95% confidence intervals were estimated.· RESULTS: Ten studies involving 282 eyes were included, 5 of which were RCTs involving 194 eyes. The application of optic capture significantly reduced both opacification of the visual axis(RR: 0.12; 95% CI: 0.02 to0.85; P =0.03) and occurrence of geometric decentration(RR: 0.09; 95% CI: 0.02 to 0.46; P =0.004). But it did not significantly affect best corrected visual acuity(BCVA)(WMD:-0.01; 95% CI:-0.07 to 0.05; P =0.75) and influence the occurrence of posterior synechia(RR: 1.53;95% CI: 0.84 to 2.77; P =0.17). Deposits in the anterior intraocular lens were significantly increased in the optic capture group early after surgery(RR: 1.40; 95% CI: 1.05 to 1.86; P =0.02) and at the last follow-up(RR: 2.30;95% CI: 1.08 to 4.92; P =0.03). The quality of the evidence was assessed as high.· CONCLUSION: The application of optic capture significantly reduces opacification of visual axis and occurrence of geometric decentration but do not significantly improve BCVA with notable safety. 展开更多
关键词 optic capture intraocular lens pediatric cataract secondary opacification Meta-analysis
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Microball lens integrated fiber probe for optical frequency domain imaging 被引量:1
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作者 Jae-Ho Han J. U. Kang 《Chinese Optics Letters》 SCIE EI CAS CSCD 2011年第9期29-31,共3页
An integrated microball lens fiber catheter probe is demonstrated, which has better lateral resolution and longer working distance than a corresponding bare fiber probe with diverging beam for Fourier domain optical c... An integrated microball lens fiber catheter probe is demonstrated, which has better lateral resolution and longer working distance than a corresponding bare fiber probe with diverging beam for Fourier domain optical coherence tomography (FDOCT). Simulation results are shown to gain the effect of the distance between the mieroball lens and the bare fiber to the focusing plane and beam width. The freedom of modifying the working distance and lateral resolution is shown. This is achieved by changing the gap distance between the single-mode fiber and the microball lens within the packaged surgical needle catheter without using an additional beam expander having a fixed length. The probe successfully acquired crosssectional images of ocular tissues from an animal sample with the proposed miniaturized imaging probe. 展开更多
关键词 Microball lens integrated fiber probe for optical frequency domain imaging THAN
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Parallel fabrication of silicon concave microlens array by femtosecond laser irradiation and mixed acid etching 被引量:4
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作者 潘安 陈涛 +1 位作者 李存霞 侯洵 《Chinese Optics Letters》 SCIE EI CAS CSCD 2016年第5期78-82,共5页
A method of multi-beam femtosecond laser irradiation combined with modified HF-HNO3-CH3COOH etching is used for the parallel fabrication of all-silicon piano-concave microlens arrays (MLAs). The laser beam is split ... A method of multi-beam femtosecond laser irradiation combined with modified HF-HNO3-CH3COOH etching is used for the parallel fabrication of all-silicon piano-concave microlens arrays (MLAs). The laser beam is split by a diffractive optical element and focused by a lens to drill microholes parallely on silicon. An HF-HNO3-H2SO4-CH3COOH solution is used to expand and polish laser-ablated microholes to form micro- lenses. Compared with the HF-HNO3-CH3COOH solution, the solution with H2SO4 can effectively reduce the etched surface roughness. The morphologies of MLAs at different laser powers and pulse numbers are observed. The image array formed by the silicon microlenses is also demonstrated. 展开更多
关键词 ETCHING Irradiation Laser beams lenses MICROlensES MICROOPTICS optical instrument lenses SILICON Surface roughness Ultrashort pulses
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Application of polycapillary x ray lens to eliminate both the effect of x ray source size and scatter of the sample in laboratory tomography 被引量:2
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作者 孙学鹏 刘志国 +6 位作者 孙天希 易龙涛 孙蔚渊 李坊佐 姜博文 马永忠 丁训良 《Chinese Optics Letters》 SCIE EI CAS CSCD 2015年第9期92-96,共5页
A tomography device based on a conventional laboratory x ray source, polycapillary parallel x ray lens (PPXRL), and polycapillary collimating x ray lens (PCXRL) is designed. The PPXRL can collect the divergent x r... A tomography device based on a conventional laboratory x ray source, polycapillary parallel x ray lens (PPXRL), and polycapillary collimating x ray lens (PCXRL) is designed. The PPXRL can collect the divergent x ray beam from the source and focus it into a quasi-parallel x ray beam with a divergence of 4.7 rarad. In the center of quasi-parallel x ray beam, there is a plateau region with an average gain in power density of 13.8 and a diameter of 630μm. The contrast of the image can be improved from 28.9% to 56.0% after adding the PCXRL between the sample and the detector. 展开更多
关键词 Electron sources optical instrument lenses TOMOGRAPHY X ray optics
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Microlens arrays prepared via colloidal microsphere templating 被引量:1
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作者 赵峰 祝名伟 詹鹏 《Chinese Optics Letters》 SCIE EI CAS CSCD 2010年第5期508-511,共4页
A simple and efficient templating method in combination with hot embossing technique is developed for fabricating large-area two-dimensional(2D) microlens arrays(MLAs) with uniform shape.By utilizing a modified mi... A simple and efficient templating method in combination with hot embossing technique is developed for fabricating large-area two-dimensional(2D) microlens arrays(MLAs) with uniform shape.By utilizing a modified microchannel method,a 2D large-area hexagonal close-packed(HCP) array of silica colloidal microspheres is prepared and serves as a template in the following hot embossing treatment to create a polycarbonate(PC) microcavity array.Then,with the obtained PC microcavity structure serving as a mold,a hot embossing process is applied to finally achieve a polymethylmethacrylate(PMMA) MLA.The effect of annealing time during the mold preparation process on the dimensions and shapes of the prepared microlens is investigated.The imaging performances of the prepared PC concave microcavities and PMMA convex microlenses are characterized by carrying out projection experiments.Our method provides a rapid and low cost approach to prepare large-area MLAs. 展开更多
关键词 MICROCAVITIES MICROOPTICS Microspheres MOLDS optical instrument lenses Silica
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Demultiplexer based on an off-axis holographic lens with low monochromatic aberrations
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作者 李森森 刘守 +1 位作者 张向苏 任雪畅 《Chinese Optics Letters》 SCIE EI CAS CSCD 2011年第9期11-13,共3页
A novel scheme is proposed, in which the aberrations in the off-axis holographic lenses used as demultiplexers are reduced to a low enough level for relatively small channel spacing. The scheme includes optimizing the... A novel scheme is proposed, in which the aberrations in the off-axis holographic lenses used as demultiplexers are reduced to a low enough level for relatively small channel spacing. The scheme includes optimizing the recording and reconstruction geometries and collimating the reconstruction wave with a gradient-index lens. A demultiplexer operated in the 1 550-nm band with 5-nm channel spacing and -∞-dB crosstalk is obtained using the scheme. The channel spacing can be decreased to 2 nm by etching the cladding of the output fibers to a smaller size. 展开更多
关键词 ABERRATIONS Holographic optical elements optical instrument lenses
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Lens density measurements by two independent psychophysical techniques
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作者 Anirbaan Mukherjee Richard A.Bone 《Eye and Vision》 SCIE 2016年第1期188-196,共9页
Background:Cataract,a leading cause of vision impairment,is due to the lens becoming excessively optically dense.Change in the lens optical density(LOD)could be a useful indicator of incipient nuclear cataract and wou... Background:Cataract,a leading cause of vision impairment,is due to the lens becoming excessively optically dense.Change in the lens optical density(LOD)could be a useful indicator of incipient nuclear cataract and would necessitate the development of accurate measurement techniques.Mapcat sf^(TM) is a heterochromatic flicker photometer for measuring macular pigment optical density(MPOD)under photopic conditions.In the process,it also measures LOD that is needed in the calculation of MPOD.LOD is then converted by the instrument to“lens equivalent age”(LEA).However,varying cone photoreceptor ratios among individuals could affect the LEA measurement.Scotopic vision is mediated by rod photoreceptors;therefore,LEA measurement under scotopic conditions potentially provides a reliable standard for assessing other methods.The study was conducted to test the level of agreement between the LEA data obtained under photopic and scotopic conditions for a sample population.We also comment on factors that might contribute to any disagreement.Methods:LEAs were obtained by Mapcat sf for 25 subjects and compared with those obtained under absolute scotopic threshold conditions.Results:The mean scotopic LEA for the subjects was 2.7 years higher than the mean photopic LEA,but this difference was not statistically significant.Measurements by the two methods were reasonably correlated(r 2=0.59,p<0.0001).Significant individual differences in LEA by the two methods were found for six of the 25 subjects.Although our calculations included a standard long-to medium-wavelength-sensitive cone ratio,we found that different ratios could be found that rendered the differences in LEA insignificant for two of these six subjects.Variability in pupil diameter during scotopic measurements was considered another potential source of discrepancy between LEAs by the two methods.Conclusion:The absolute threshold technique,with long adaptation times,is probably impractical for routine lens density measurement,whereas Mapcat sf provided a rapid,straightforward test that may find its application in optometric/ophthalmic practice. 展开更多
关键词 CATARACT Heterochromatic flicker photometry lens optical density Absolute threshold PHOTOPIC SCOTOPIC
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