Optical vortices generated by the conventional vortex lens are usually disturbed by the undesired higher-order foci,which may lead to additional artifacts and thus degrade the contrast sensitivity. In this work, we pr...Optical vortices generated by the conventional vortex lens are usually disturbed by the undesired higher-order foci,which may lead to additional artifacts and thus degrade the contrast sensitivity. In this work, we propose an efficient methodology to combine the merit of elliptical reflective zone plates(ERZPs) and the advantage of spiral zone plates(SZPs) in establishing a specific single optical element, termed elliptical reflective annulus quadrangle-element coded spiral zone plates(ERAQSZPs) to generate single-focus phase singularity. Differing from the abrupt reflectance of the ERZPs, a series of randomly distributed nanometer apertures are adopted to realize the sinusoidal reflectance. Typically, according to our physical design, the ERAQSZPs are fabricated on a bulk substrate;therefore, the new idea can significantly reduce the difficulty in the fabrication process. Based on the Kirchhoff diffraction theory and convolution theorem, the focusing performance of ERAQSZPs is calculated. The results reveal that apart from the capability of generating optical vortices,ERAQSZPs can also integrate the function of focusing, energy selection, higher-order foci elimination, as well as high spectral resolution together. In addition, the focusing properties can be further improved by appropriately adjusting the parameters, such as zone number and the size of the consisted primitives. These findings are expected to direct a new direction toward improving the performance of optical capture, x-ray fluorescence spectra, and forbidden transition.展开更多
Dear Editor,Ocular trauma can cause severe visual functional impairment.The management is often challenging due to multistructures affected.Toric intraocular lens(IOL)implantation can be an effective method for the tr...Dear Editor,Ocular trauma can cause severe visual functional impairment.The management is often challenging due to multistructures affected.Toric intraocular lens(IOL)implantation can be an effective method for the treatment of traumatic corneal astigmatism^([1]).Because of the optic design,the toric IOLs require more precise centration.Conventional toric IOL fixation methods require two-point fixation,which make the IOL tilting unpredictable,and have not been the first choice for patients without sufficient capsule and iris support.Now,we report a rare case of a woman with posttraumatic aniridia.展开更多
Background: The availability of premium intraocular lenses (IOL), including toric, multifocal, and EDOF, has become very sophisticated and now demands accurate biometric measurement accuracy. The Pentacam AXL and IOL ...Background: The availability of premium intraocular lenses (IOL), including toric, multifocal, and EDOF, has become very sophisticated and now demands accurate biometric measurement accuracy. The Pentacam AXL and IOL Master 700 are often used for optical biometry and they are available in the market today. They can also be used to measure the parameters needed in the IOL calculation using the latest generation formulas, such as the Barett Universal II. Therefore, this study aims to compare the accuracy of refraction results between Pentacam AXL compared to IOL Master 700 after cataract surgery with the Barett Universal-II formula. Method: A total of 64 eyes from 64 patients who had a preoperative examination with IOL Master 700 and Pentacam AXL were included in this study. Parameters such as K, ACD, LT, WTW, and AL were then compared between the two tools. Prediction error values were also calculated and compared based on the difference between the Spherical equivalent (SE) of subjective refraction results after 4 weeks of surgery with their refractive prediction targets. Results: There was no statistically significant difference in the parameters measured from the two tools except ACD and WTW. Furthermore, LT was difficult to obtain on the Pentacam AXL due to penetration problems, as well as in patients with significant lens opacities. The percentage of error prediction values that reach ± 0.50 D on Pentacam AXL and IOL Master 700 was 70.3% and 73.5%, respectively. However, the average prediction error that was close to emmetropia with IOL Master 700 was greater compared to the other tool. Conclusion: Pentacam AXL has a fairly good accuracy for refraction prediction compared to IOL Master 700. However, it is still necessary to optimize its constants to obtain optimal results.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos.12174350,12275253,and 12275250)the Program of Science and Technology on Plasma Physics Laboratory,China Academy of Engineering Physics (Grant No.6142A04200107)the National Natural Science Foundation,Youth Fund (Grant No.12105268)。
文摘Optical vortices generated by the conventional vortex lens are usually disturbed by the undesired higher-order foci,which may lead to additional artifacts and thus degrade the contrast sensitivity. In this work, we propose an efficient methodology to combine the merit of elliptical reflective zone plates(ERZPs) and the advantage of spiral zone plates(SZPs) in establishing a specific single optical element, termed elliptical reflective annulus quadrangle-element coded spiral zone plates(ERAQSZPs) to generate single-focus phase singularity. Differing from the abrupt reflectance of the ERZPs, a series of randomly distributed nanometer apertures are adopted to realize the sinusoidal reflectance. Typically, according to our physical design, the ERAQSZPs are fabricated on a bulk substrate;therefore, the new idea can significantly reduce the difficulty in the fabrication process. Based on the Kirchhoff diffraction theory and convolution theorem, the focusing performance of ERAQSZPs is calculated. The results reveal that apart from the capability of generating optical vortices,ERAQSZPs can also integrate the function of focusing, energy selection, higher-order foci elimination, as well as high spectral resolution together. In addition, the focusing properties can be further improved by appropriately adjusting the parameters, such as zone number and the size of the consisted primitives. These findings are expected to direct a new direction toward improving the performance of optical capture, x-ray fluorescence spectra, and forbidden transition.
基金Supported by Tianjin Key Medical Discipline(Specialty)Construction Project(No.NTJYXZDXK-037A).
文摘Dear Editor,Ocular trauma can cause severe visual functional impairment.The management is often challenging due to multistructures affected.Toric intraocular lens(IOL)implantation can be an effective method for the treatment of traumatic corneal astigmatism^([1]).Because of the optic design,the toric IOLs require more precise centration.Conventional toric IOL fixation methods require two-point fixation,which make the IOL tilting unpredictable,and have not been the first choice for patients without sufficient capsule and iris support.Now,we report a rare case of a woman with posttraumatic aniridia.
文摘Background: The availability of premium intraocular lenses (IOL), including toric, multifocal, and EDOF, has become very sophisticated and now demands accurate biometric measurement accuracy. The Pentacam AXL and IOL Master 700 are often used for optical biometry and they are available in the market today. They can also be used to measure the parameters needed in the IOL calculation using the latest generation formulas, such as the Barett Universal II. Therefore, this study aims to compare the accuracy of refraction results between Pentacam AXL compared to IOL Master 700 after cataract surgery with the Barett Universal-II formula. Method: A total of 64 eyes from 64 patients who had a preoperative examination with IOL Master 700 and Pentacam AXL were included in this study. Parameters such as K, ACD, LT, WTW, and AL were then compared between the two tools. Prediction error values were also calculated and compared based on the difference between the Spherical equivalent (SE) of subjective refraction results after 4 weeks of surgery with their refractive prediction targets. Results: There was no statistically significant difference in the parameters measured from the two tools except ACD and WTW. Furthermore, LT was difficult to obtain on the Pentacam AXL due to penetration problems, as well as in patients with significant lens opacities. The percentage of error prediction values that reach ± 0.50 D on Pentacam AXL and IOL Master 700 was 70.3% and 73.5%, respectively. However, the average prediction error that was close to emmetropia with IOL Master 700 was greater compared to the other tool. Conclusion: Pentacam AXL has a fairly good accuracy for refraction prediction compared to IOL Master 700. However, it is still necessary to optimize its constants to obtain optimal results.
