Light Sword Optical Element Research Articles

Experimental evaluation of the light sword lens performance with a variable pupil size

This paper presents an experimental study designed to test the performance of the light sword lens (LSL) with different pupil sizes. To do so, Snellen optotype images obtained by a monofocal lens either with or without an LSL, were compared. Images were obtained for three different pupil sizes at several target vergences. The correlation coefficient and through-focus curves were obtained and compared. The experimental results show differences in the contrast and the depth of focus with different pupil sizes using the monofocal lens without an LSL. In contrast, when using the monofocal lens in combination with the LSL, the quality of the images is similar for all pupils and target vergences used, with slight differences only in halos and contrast. Full Text: PDF ReferencesG. Mikula, Z. Jaroszewicz, A. Kolodziejczyk, K. Petelczyc, M. Sypek, G. P. Agrawal, "Imaging with extended focal depth by means of lenses with radial and angular modulation", Opt Express 15, 9184, (2007). CrossRef A. Kolodziejczyk, S. Bará, Z. Jaroszewicz, M. Sypek, "The Light Sword Optical Element—a New Diffraction Structure with Extended Depth of Focus", J. Mod Opt. 37, 1283, (1990). CrossRef K. Petelczyc et al, "Presbyopia compensation with a light sword optical element of a variable diameter", Photonics Lett. Pol. 1, 55 (2009). DirectLink A. Mira-Agudelo et al, "Compensation of Presbyopia With the Light Sword Lens", Invest Ophthalmol Vis Sci 57, 6871, (2016). CrossRef R.A. Fisher, Statistical Methods for Research Workers (New York, Hafner, 13th Ed., 1958) CrossRef

Multifunctional Light Sword Metasurface Lens

The depth of focus of an imaging system determines the range of change for both the position of focal plane and image plane. Although a typical light sword optical element with angular modulation of phase transmittance can extend its focus of depth due to its angular variation of the optical power, it lacks rotational symmetry and exhibits a junction, rendering its fabrication extremely difficult. Optical metasurfaces provide an unusual approach to develop such a device due to their unprecedented capability in the manipulation of light propagation in a desirable manner. We propose and experimentally demonstrate a light sword metasurface lens with multiple functionalities. The position of focal segments can be controlled by changing the polarization state of the incident light. The developed ultrathin, ultraflat device can facilitate device miniaturization and system integration and may find applications in various fields such as optical coupling, imaging, and interconnections.

Imaging with extended depth of field by means of the peacock eye optical element

The paper presents imaging properties of the peacock eye optical element. Its abilities for imaging with extended depth of field is illustrated experimentally in monochromatic as well as polychromatic light. According to the obtained results the element makes possible to maintain the acceptable resolution, contrast and brightness of the output images for a wide range of defocusing. Full Text: PDF ReferencesJ. Ares, R. Flores, S. Bara, and Z. Jaroszewicz, "Presbyopia Compensation with a Quartic Axicon", Optom. Vis. Sci. 82, 107 (2005). CrossRef G.-m. Dai, "Optical surface optimization for the correction of presbyopia", Appl. Opt. 45, 4184 (2006). CrossRef Z. Liu, A. Flores, M. R. Wang, and J. J. Yang, "Diffractive infrared lens with extended depth of focus", Opt. Eng. 46, 018002 (1-9) (2007). CrossRef E. E. Garcia-Guerrero, E. R. Mendez, H. M. Escamilla, T. A. Leskova, and A. A. Maradudin, "Design and fabrication of random phase diffusers for extending the depth of focus", Opt. Express 15, 910 (2007). CrossRef J. Lin, J. Liu, J. Ye, and S. Liu, "Design of microlenses with long focal depth based on the general focal length function", J. Opt. Soc. Am. A 24, 1747 (2007). CrossRef N. Davidson, A. A. Friesem, and E. Hasman, "Holographic axilens: high resolution and long focal depth", Opt. Lett. 16, 523 (1991). CrossRef A. Kołodziejczyk, S. Bara, Z. Jaroszewicz, and M. Sypek, "The Light Sword Optical Element?a New Diffraction Structure with Extended Depth of Focus", J. Mod. Opt. 37, 1283 (1990). CrossRef K. Petelczyc, S. Bará, A. Ciro Lopez, Z. Jaroszewicz, K. Kakarenko, A. Kolodziejczyk, and M. Sypek, "Imaging properties of the light sword optical element used as a contact lens in a presbyopic eye model", Opt. Express 19, 25602 (2011). CrossRef K. Kakarenko, I. Ducin, K. Grabowiecki, Z. Jaroszewicz, A. Kolodziejczyk, A. Mira-Agudelo, K. Petelczyc, A. Składowska, M. Sypek, "Assessment of imaging with extended depth-of-field by means of the light sword lens in terms of visual acuity scale", Biomed Opt Express 6, 1738 (2015). CrossRef Z. Jaroszewicz, A. Kołodziejczyk, D. Mouriz, and J. Sochacki, "Generalized Zone Plates Focusing Light into Arbitrary Line Segments", J. Mod. Opt. 40, 601 (1993). CrossRef L. A. Romero, M. S. Millían, Z. Jaroszewicz, A. Kolodziejczyk, "Double peacock eye optical element for extended focal depth imaging with ophthalmic applications", J. Biomed. Opt. 17 046013 (2012). CrossRef

Conical light sword optical beam and its healing property

A new diffractive optical element, named as a conical light sword optical element, is presented. In the focal volume, this element produces a helical amplitude profile that can be used as an optical twister. We have experimentally demonstrated the optical healing property of the conical light sword optical beam (CLSOB). This healing property comes from the transverse helical energy flow, due to the evolution of multiple unipolar vortices in the propagation of CLSOB. We envisage that this spiral intensity profile and optical healing property of the beam find potential applications in propagation through a scattering and turbulent media, imaging with extended depth of field, and in optical tweezers.

Hyper Gaussian windows with fractional wavefronts

For reducing the impact of focus errors on the modulation transfer function (MTF), we explore the use of fractional phase power masks combined with either sub Gaussian windows, or super Gaussian windows. We present a sub Gaussian mask combined, with an asymmetric fractional phase profile, which reduces both the variations of the MTF vs. focus errors and the oscillations of the MTF around its tendency curve. However, this mask also reduces the light throughput by a factor of two. Full Text: PDF References M. Mino, Y. Okano, "Improvement in the OTF of a Defocused Optical System Through the Use of Shaded Apertures", Appl. Opt. 10, 2219-2225 (1971). CrossRef J. Ojeda-Castaneda, L. R. Berriel Valdos and E. L. Montes, "Line-spread function relatively insensitive to defocus", Opt. Lett. 8, 458-460 (1983). CrossRef J. Ojeda-Castaneda, L. R. Berriel-Valdos, E. Montes, "Ambiguity function as a design tool for high focal depth", Appl. Opt. 27, 790-795, (1988). CrossRef E. R. Dowski, T. W. Cathey, "Extended depth of field through wave-front coding", Appl. Opt. 34, 1859-1865 (1995). CrossRef N. George, W. Chi, "Extended depth of field using a logarithmic asphere", J. Opt. A - Pure Appl. Opt. 5, 157-163 (2003). CrossRef A. Sauceda and J. Ojeda-Castaneda, "High focal depth with fractional-power wave fronts", Opt. Lett. 29, 560-562 (2004). CrossRef A. Castro and J. Ojeda-Castaneda, "Asymmetric Phase Masks for Extended Depth of Field", Appl. Opt. 43, 3474-3479 (2004). CrossRef S. Mezouari, G. Muyo, A. R. Harvey, "Circularly symmetric phase filters for control of primary third-order aberrations: coma and astigmatism", J. Opt. Soc. Am. A 23, 1058-1062 (2006). CrossRef J. Ares García, S. Bará, M. Gomez García, Z. Jaroszewicz, A. Kolodziejczyk, and K. Petelczyc, "Imaging with extended focal depth by means of the refractive light sword optical element", Opt. Exp. 16, 18371 (2008). CrossRef J. Ojeda-Castaneda, J. E. A. Landgrave and C. M. Gómez-Sarabia, "Conjugate phase plate use in analysis of the frequency response of imaging systems designed for extended depth of field", Appl. Opt. 47, E99 ? E105 (2008). CrossRef J. Ojeda-Casta-eda and Arturo Noyola-Isgleas, "High focal depth by apodization and digital restoration", Appl. Opt. 27, 2583-2586 (1988). CrossRef W. T. Cathey and E. R. Dowski, "New Paradigm for Imaging Systems", Appl. Opt. 41, 6080-6092 (2002). CrossRef J. Ojeda-Castaneda, E. Yépez-Vidal, E. García-Almanza and C. M. Gómez-Sarabia, "Tunable Gaussian mask for extending the depth of field", Photonics Letters of Poland, Vol. 4 (3), 115-117 (2012). DirectLink N. Brenner and C. Rader, "A new principle for fast Fourier transformation", IEEE Acoustics, Speech & Signal Processing 24, 264?266 (1976). CrossRef

Visual Strehl Performance of IOL Designs with Extended Depth of Focus

The use of monofocal, bifocal, or multifocal intraocular lenses (IOLs) is a common option to restore the refractive power of the eye in aphakic patients after cataract surgery. In this article, we study the predicted performance of two new designs of IOL, both with extended depth of focus: the quartic axicon and the light sword optical element (LSOE). These elements provide continuous focal segments spanning the range of dioptric power required for presbyopia compensation. The performance analysis is based on the visual Strehl ratio (SR) computed in the spatial frequency domain, a neuro-optical quality metric that takes into account the effects of both the optical transfer function and the neural contrast sensitivity function. Furthermore, the classical SR and compound modulation transfer function were calculated. Some conventional transmittances of commercially available IOLs are also analyzed. The LSOE design has a more homogeneous behavior than other available solutions, providing a more uniform image quality over a significant fraction of the required addition range. The angular average of the visual SR computed in the spatial frequency domain and compound modulation transfer function indicate that both designs of extended depth of focus elements provide better optical quality on the whole addition range, except at the end points, than the discrete focus designs. The LSOE performed better than the quartic axicon in terms of uniformity of image quality within the same range.

Tunable Gaussian mask for extending the depth of field

We present the use of two asymmetrical amplitude masks, for generating a tunable Gaussian filter. The two masks work as a pair. By introducing a lateral displacement, between the members of the pair, one can tune the width of the Gaussian filter. This tunable mask is useful for controlling unwanted oscillations in the MTFs, which are associated to the use of phase filters extending the depth of field. Full Text: PDF References G. Hauesler, "A method to increase the depth of focus by two step image processing", Opt. Commun. 6, 38 (1972). CrossRef J. Ojeda-Casta?eda, R. Ramos, A. Noyola-Isgleas, "High focal depth by apodization and digital restoration", Appl. Opt. 27, 2583 (1988). CrossRef M. Mino, Y. Okano, "Improvement in the OTF of a Defocused Optical System Through the Use of Shaded Apertures", Appl. Opt. 10, 2219 (1971). CrossRef J. Ojeda-Casta?eda, L.R. Berriel Valdos, E. L. Montes, "Line-spread function relatively insensitive to defocus", Opt. Lett. 8(8), 458 (1983). CrossRef J. Ojeda-Casta?eda, L.R. Berriel-Valdos, E. Montes, "Spatial filter for increasing the depth of focus", Opt. Lett. 10(11), 520 (1985). CrossRef J. Ojeda-Casta?eda, A. Díaz, "High focal depth by quasibifocus", Appl. Opt. 27, 4163 (1988). CrossRef J. Ojeda-Casta?eda, L.R Berriel-Valdos, E. Montes, "Ambiguity function as a design tool for high focal depth", Appl. Opt. 27(4), 790 (1988). CrossRef E.R. Dowski, T.W. Cathey, "Extended depth of field through wave-front coding", Appl. Opt. 34, 1859 (1995). CrossRef H. Wang, F. Gan, "High Focal Depth with a Pure-Phase Apodizer", Appl. Opt. 40, 5658 (2001). CrossRef N. George, W. Chi, "Extended depth of field using a logarithmic asphere", J. Opt. A: Pure Appl. Opt. 5, S157 (2003). CrossRef A. Castro, J. Ojeda-Casta?eda, "Asymmetric Phase Masks for Extended Depth of Field", Appl. Opt. 43(17), 1 (2004). CrossRef Á. Sauceda-Carvajal, J. Ojeda-Casta?eda, "High focal depth with fractional-power wave fronts", Opt. Lett. 29(6), 560 (2004). CrossRef G. Mikula, Z. Jaroszewicz, A. Kolodziejczyk, K. Petelczyc, M. Sypek, "Imaging with extended focal depth by means of lenses with radial and angular modulation", Opt. Exp. 15, 9184 (2007). CrossRef J. Ojeda-Castaneda, J.E.A. Landgrave, C.M. Gómez-Sarabia, "Conjugate phase plate use in analysis of the frequency response of imaging systems designed for extended depth of field", Appl. Opt. 47, E99 ? E105 (2008). CrossRef J. Ares García, S. Bará, M. Gomez García, Z. Jaroszewicz, A. Kolodziejczyk, K. Petelczyc, "Imaging with extended focal depth by means of the refractive light sword optical element", Opt. Exp. 16, 18371 (2008). CrossRef G. Muyo, A. Singh, M. Andersson, D. Huckridge, A. Wood, A.R. Harvey, "Infrared imaging with a wavefront-coded singlet lens", Opt. Exp. 17(23), 21118 (2009). CrossRef J. Ojeda-Casta?eda, E. Yépez-Vidal, E. García-Almanza, "Noncoherent imagery: a novel approach", Phot. Lett. Poland 2(4), 162 (2010). CrossRef H.H. Hopkins, Wave Theory of Aberrations (Oxford, 1950). K.-H. Brenner, A.W. Lohmann, J. Ojeda-Castaneda, "The ambiguity function as a polar display of the OTF", Opt. Comm. 77, 89 (1982). CrossRef

Imaging properties of the light sword optical element used as a contact lens in a presbyopic eye model

The paper analyzes the imaging properties of the light sword optical element (LSOE) applied as a contact lens to the presbyopic human eye. We performed our studies with a human eye model based on the Gullstrand parameterization. In order to quantify the discussion concerning imaging with extended depth of focus, we introduced quantitative parameters characterizing output images of optotypes obtained in numerical simulations. The quality of the images formed by the LSOE were compared with those created by a presbyopic human eye, reading glasses and a quartic inverse axicon. Then we complemented the numerical results by an experiment where a 3D scene was imaged by means of the refractive LSOE correcting an artificial eye based on the Gullstrand model. According to performed simulations and experiments the LSOE exhibits abilities for presbyopia correction in a wide range of functional vision distances.

Strehl ratios characterizing optical elements designed for presbyopia compensation

We present results of numerical analysis of the Strehl ratio characteristics for the light sword optical element (LSOE). For comparison there were analyzed other optical imaging elements proposed for compensation of presbyopia such as the bifocal lens, the trifocal lens, the stenopeic contact lens, and elements with extended depth of focus (EDOF), such as the logarithmic and quartic axicons. The simulations were based on a human eye's model being a simplified version of the Gullstrand model. The results obtained allow to state that the LSOE exhibits much more uniform characteristics of the Strehl ratio comparing with other known hitherto elements and therefore it could be a promising aid to compensate for the insufficient accommodation range of the human eye.

Contrast transfer characteristics of the light sword optical element designed for presbyopia compensations

The paper discusses the abilities of the light sword optical element (LSOE) for presbyopia compensation. The imaging properties are analyzed by means of the modulation transfer functions and output images of the star resolution test. All numerical calculations are performed assuming an optical set-up simulating the presbyopic human eye with 3 mm pupil acting on-axis and based on the Gullstrand model. In order to have a meaningful comparison we expand our study and present adequate analysis for other elements potentially useful in ophthalmology as reading glasses, bifocal lenses and axicons. According to the obtained results the LSOE can successfully realize vision with an extended depth of field. Under assumed conditions the element makes possible the compensation of an assumed defocus up to 4 dioptres. The output images formed by the LSOE are well recognizable and have acceptable qualities for near as well as far object distances.

Imaging with extended focal depth by means of the refractive light sword optical element

The paper presents first experiments with a refractive light sword optical element (LSOE). A refractive version of the LSOE was prepared in photoresist by gray scale photolithography. Then we examined chromatic aberrations of the produced element and compared them with those corresponding to two different lenses. For this purpose we performed two experiments, the first one where white light illumination was used and the latter one by the help of monochromatic illumination with three different wavelengths. The obtained results lead to the conclusion that the refractive LSOE does not exhibit significant chromatic aberrations and can be successfully used for imaging with extended depth of focus in polychromatic illumination.

Three dimensional analysis of chromatic aberration in diffractive elements with extended depth of focus

The paper presents the polychromatic analysis of two diffractive optical elements with extended depth of focus: the linear axicon and the light sword optical element. Chromatic aberration produces axial displacement of the focal segment line. Thus, we explore the possibility of extending the focal depth of these elements to permit superposition of the chromatic foci. In the case of an axicon, we achieve an achromatic zone where focusing is produced. In the case of the light sword element, we show that the focusing segment is out of axis. Therefore a superposition of colors is produced, but not on axis overlapping. Instead, three colored and separated foci are simultaneously obtained in a single plane. Three dimensional structures of the propagated beams are analyzed in order to provide better understanding of the properties and applications of such elements.

Imaging with extended focal depth by means of lenses with radial and angular modulation

The paper presents imaging properties of modified lenses with the radial and the angular modulation. We analyze three following optical elements with moderate numerical apertures: the forward logarithmic axicon and the axilens representing the radial modulation as well as the light sword optical element being a counterpart of the axilens with the angular modulation. The abilities of the elements for imaging with extended depth of focus are discussed in detail with the help of structures of output images and modulation transfer functions corresponding to them. According to the obtained results only the angular modulation of the lens makes possible to maintain the acceptable resolution, contrast and brightness of the output images for a wide range of defocusing. Therefore optical elements with angular modulations and moderate numerical apertures seem to be especially suitable for imaging with extended focal depth.

Diffractive elements for imaging with extended depth of focus

We present the abilities of diffractive elements for imaging with extended depth of focus. The elements of interest belong to the class of diffractive structures focusing incident light into a segment of the optical axis. We describe the imaging properties of the two following elements of this kind: the annular axicon and the light sword optical element (LSOE). In particular, the point spread functions and the modulation transfer functions of axicons and LSOEs are analyzed experimentally and numerically in detail. The obtained results correspond to different defocusing parameters. The performed experiments confirm the usefulness of axicons and LSOEs for imaging with extended depth of focus.

The Light Sword Optical Element—a New Diffraction Structure with Extended Depth of Focus

Abstract This letter introduces a novel diffraction structure, the light sword optical element, with extended depth of focus.