High-speed simultaneous measurement of refractive index and thickness of transparent plates by low-coherence interferometry and confocal optics

Ohmi, Masato; Nishi, Hisami; Konishi, Y.; Yamada, Yoshiyuki; Haruna, Masamitsu

doi:10.1088/0957-0233/15/8/017

Cited by 31 publications

(11 citation statements)

References 10 publications

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“…Interferometer‐based systems have been used to measure the refractive index or its variation 9–14. Other methods including return loss2 and Abbé refractometer4,15 have also been used.…”

Section: Introductionmentioning

confidence: 99%

Effect of packing pressure on refractive index variation in injection molding of precision plastic optical lens

Yang¹,

Su²,

Huang³

et al. 2011

Adv Polym Technol

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ABSTRACT:In this study, refractive index variation in injection-molded polymethylmethacrylate optical lenses under different levels of packing pressure was evaluated using a Shack-Hartmann wavefront sensor-based metrology system. The experimental results showed that optical polymer's refractive index exhibits a considerable amount of variation for the lenses molded under different packing pressures. Specifically, within the range investigated in this study, refractive index variation is more uniform when higher packing pressure was used but less so for lower packing pressure. Refractive index variation is believed to be the result of density variation, which itself is caused by shrinkage variation at different packing conditions. In addition, using density information in the plastic lenses predicted by finite element simulation, refractive index variation was numerically determined using the differential Lorentz-Lorenz equation and the results were in good agreement with the experiments conducted in this research. C

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Section: Introductionmentioning

confidence: 99%

Effect of packing pressure on refractive index variation in injection molding of precision plastic optical lens

Yang¹,

Su²,

Huang³

et al. 2011

Adv Polym Technol

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“…Такие представления эффективны и с прикладной точки зрения для количественной оценки декорреляции волновых полей с широкими частотными и угловыми спектрами при их прохождении через границы раздела сред с различными показателями преломления [30,38,39], для определения геометрических и оптических параметров объектов [40,41], для развития методов корреляционной интерференционной микроскопии [10,13,39,42] с целью расширения их измерительных возможностей.…”

Section: заключениеunclassified

Мгновенные Спекл-Модулированные Интерференционные Изображения И Когерентные Эффекты В Оптической Микроскопии Тонких Слоев

Максимова¹,

Мысина²,

Дьяченко³

et al. 2020

Журнал Технической Физики

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The formation of instantaneous speckle-modulated interference images of thin transparent layers in an optical microscope under an illuminating quasi-monochromatic or frequency broadband wave field with wide angular spectra and coherent effects are considered. Instantaneous speckle-modulated interference images of the layer in the transverse and longitudinal sections of the total wave field reflected by the layer are obtained by numerical simulation of the spatial distributions of the complex amplitude of the wave fields reflected by the layer faces and their superposition. The results of computer simulation of instantaneous speckle-modulated and experimentally observed averaged interference images of the layer under quasi-monochromatic and frequency broadband illuminating layer field with different width of the angular spectrum are presented. The mutual correlation of instantaneous speckle fields reflected by the layer faces and the effects of the influence of the width of the angular and frequency spectra of the illuminating field on the contrast of experimentally observed interference images of the layer are studied numerically. On the basis of the instantaneous speckle-modulation of the wave field the physical mechanism of the influence of angular width and the width of the frequency spectra of the illuminating field on the mutual coherence of the interfering wave fields is investigated.

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“…There have been a number of published reports on the application of optical tools for measurement of thickness, 9,10 refractive index, 11,12 or both [13][14][15][16] of transparent media or biological samples. These tools, however, impose some specific limitations for testing thickness and refractive index of IOL in terms of spatial sample alignment, testing accuracy, variations of IOL designs, and calibration requirements.…”

Section: Introductionmentioning

confidence: 99%

“…Optical coherence tomography (OCT)-based methods 11,14 do not provide superior testing accuracy compared to confocal microscope method and have the OCT limitation in measuring thickness of nontransparent objects. The conventional confocal microscopy-based platforms 13,16 have also some limitations for testing IOL in terms of confocal design and calibration requirements. In this work, we present a noncontact method for precise IOL thickness and refractive-index measurement employing an advanced fiber-optic self-calibrating dual-confocal laser caliper approach.…”

Section: Introductionmentioning

confidence: 99%

Noncontact method for sensing thickness and refractive index of intraocular lens implants using a self-calibrating dual-confocal laser caliper

Kim

James

Calogero³

et al. 2018

J. Biomed. Opt.

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We present a fiber-optic dual-confocal laser caliper method for noncontact high-precision sensing and measuring thickness and refractive index of intraocular lens (IOL) implants. The principle of the method is based on sensing and measuring the confocal intensity response of the laser beam reflection from the opposite object surfaces, which provides the advanced feature of having no limitations on the object shape, thickness, and transparency. Using single-mode optical fibers and a 658-nm laser source, the thickness measurement accuracy was assessed to be as high as 5 μm. In addition, refractive index of a transparent object with thickness smaller than the working distance of the focusing lenses can be measured. The thickness and refractive index of a planoconvex IOL were measured with a high accuracy.

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High-speed simultaneous measurement of refractive index and thickness of transparent plates by low-coherence interferometry and confocal optics

Cited by 31 publications

References 10 publications

Effect of packing pressure on refractive index variation in injection molding of precision plastic optical lens

Effect of packing pressure on refractive index variation in injection molding of precision plastic optical lens

Мгновенные Спекл-Модулированные Интерференционные Изображения И Когерентные Эффекты В Оптической Микроскопии Тонких Слоев

Noncontact method for sensing thickness and refractive index of intraocular lens implants using a self-calibrating dual-confocal laser caliper

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