Hysteresis characterization of an electrically focus-tunable lens

Torres-Sepúlveda, Walter; Henao, Julián; Morales-Marín, Jennyfer; Mira-Agudelo, Alejandro; Rueda, Édgar

doi:10.1117/1.oe.59.4.044103

Cited by 8 publications

(2 citation statements)

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“…Furthermore, the current applied to the Optotune lens seems to result in slightly different values of focal power, depending on the current that was applied before and the range that is covered within a measurement run. Recent research on the characterization of Optotune’s electrically focus-tunable lenses supports this observation by confirming hysteresis in three different lens models [ 29 , 30 ]. When treating the measurement of 0 D as an outlier, Figure 3 shows an obvious trend for the lens measurements to increase toward higher absolute values of defocus compared to the nominal values of the model eyes.…”

Section: Discussionmentioning

confidence: 62%

Development and Testing of a Compact Autorefractor Based on Double-Pass Imaging

Emmerich

Ohlendorf

Leube

et al. 2022

Sensors

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Autorefraction is an objective way to determine the refractive error of the eye, without the need for feedback by the patient or a well-educated practitioner. To make refractive measurements more accessible in the background of the growing prevalence of myopia, a compact autorefractor was built, containing only few optical components and relying on double-pass imaging and the physical properties of the point-spread function and digital image processing instead. A method was developed to analyze spherical defocus as well as the defocus and angle of astigmatism. The device was tested using calibrator eye models in a range of ± 15 D spherical defocus and −3 D astigmatic defocus. Reliable results could be achieved across the whole measurement range, with only a small increase in deviation toward high values of refractive errors, showing the feasibility of a PSF-based approach for a compact and low-cost solution for objective measurements of refractive error.

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Section: Discussionmentioning

confidence: 62%

Development and Testing of a Compact Autorefractor Based on Double-Pass Imaging

Emmerich

Ohlendorf

Leube

et al. 2022

Sensors

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“…However, more degrees of freedom are required for greater aberration correction of high-NA lenses and when imaging in non-homogeneous media. ETLs exhibit significant hysteresis; a study of ETLs produced by Optotune [ 9 ] reported hysteresis up to 1D of optical power that was dependent on the history of the applied current used to refocus the lens.…”

Section: Introductionmentioning

confidence: 99%

Video-rate remote refocusing through continuous oscillation of a membrane deformable mirror

Wright¹,

Sparks²,

Paterson³

et al. 2021

J. Phys. Photonics

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This paper presents the use of a deformable mirror (DM) configured to rapidly refocus a microscope employing a high numerical aperture (NA) objective lens. An Alpao DM97-15 membrane DM was used to refocus a 40×/0.80 NA water-immersion objective through a defocus range of −50–50 μ m at 26.3 sweeps s −1 . We achieved imaging with a mean Strehl metric of >0.6 over a field of view in the sample of 200 × 200 μ m 2 over a defocus range of 77 μ m. We describe an optimisation procedure where the mirror is swept continuously in order to avoid known problems of hysteresis associated with the membrane DM employed. This work demonstrates that a DM-based refocusing system could in the future be used in light-sheet fluorescence microscopes to achieve video-rate volumetric imaging.

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