Imaging performance of an ultra-precision machining-based Fresnel lens in ophthalmic devices

Vu, Van Truong; Hasan, Syed Azkar Ui; Youn, Hongseok; Park, Youngdurk; Lee, Hocheol

doi:10.1364/oe.438531

Cited by 12 publications

(6 citation statements)

References 36 publications

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“…Moreover, diamond tools have inherent tool nose radius, clearance angle, rake angle, and different tool geometry, which plays a key role in mathematical calculation and experimental preparation [114]. Moreover, ultra-precision diamond cutting has an effective tool path generation strategy for complex surface structures, which has great advantages in the machining of micro-structures [114][115][116]. Early diamond tools were limited to machining soft and malleable non-ferrous metal materials, such as aluminum and copper [117].…”

Section: Liga Technologymentioning

confidence: 99%

A Review of Advances in Fabrication Methods and Assistive Technologies of Micro-Structured Surfaces

Zhang

Cao

et al. 2023

Processes

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Micro-structured surfaces possess excellent properties of friction, lubrication, drag reduction, antibacterial, and self-cleaning, which have been widely applied in optical, medical, national defense, aerospace fields, etc. Therefore, it is requisite to study the fabrication methods of micro-structures to improve the accuracy and enhance the performance of micro-structures. At present, there are plenty of studies focusing on the preparation of micro-structures; therefore, systematic review of the technologies and developing trend on the fabrication of micro-structures are needed. In present review, the fabrication methods of various micro-structures are compared and summarized. Specially, the characteristics and applications of ultra-precision machining (UPM) technology in the fabrication of micro-structures are mainly discussed. Additionally, the assistive technologies applied into UPM, such as fast tool servo (FTS) technology and slow tool servo (STS) technology to fabricate micro-structures with different characteristics are summarized. Finally, the principal characteristics and applications of fly cutting technology in manufacturing special micro-structures are presented. From the review, it is found that by combining different machining methods to prepare the base layer surface first and then fabricate the sublayer surface, the advantages of different machining technologies can be greatly exerted, which is of great significance for the preparation of multi-layer and multi-scale micro-structures. Furthermore, the combination of ultra-precision fly cutting and FTS/STS possess advantages in realizing complex micro-structures with high aspect ratio and high resolution. However, residual tool marks and material recovery are still the key factors affecting the form accuracy of machined micro-structures. This review provides advances in fabrication methods and assistive technologies of micro-structured surfaces, which serves as the guidance for both fabrication and application of multi-layer and multi-scale micro-structures.

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Section: Liga Technologymentioning

confidence: 99%

A Review of Advances in Fabrication Methods and Assistive Technologies of Micro-Structured Surfaces

Zhang

Cao

et al. 2023

Processes

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“…To optimise the design of optical systems, additional components are typically added to reduce optical aberrations [21][22][23]. The elimination of chromatic aberrations is achieved by means of two lenses with positive and negative dispersion [24]. Diffractive optical elements with negative dispersion are well suited to achieve achromatic aberrations by applying optical elements with micro-nano characteristics to the surface of the lens, forming an aspheric Fresnel lens [25][26][27].…”

Section: Main Display Imaging Systemsmentioning

confidence: 99%

Research on Virtual Reality Head-Mounted Displays based on MEMS Technology

Ren

Dong

et al. 2023

J. Phys.: Conf. Ser.

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In order to render the gaze area and increase the pixels per degree of the area, this virtual reality head-mounted display device adds two MEMS 2D miniature scanning mirrors to the main display imaging, with a laser diode as the projection light source and the main display as the projection receiving screen. The light emitted by the laser lamp is projected onto the main display through multiple reflections. Through pre-processing of the image of the main display and the projected display, the image of the main display is combined with the projected image to achieve the rendering effect. It is integrated with an eye tracking system that allows the projected image to be consistently projected on the human eye area. The projection image is projected over the entire imaging area of the main display by resonant rotation of two MEMS 2D microscope mirrors.

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“…In particular, the nonimaging Fresnel lenses are designed with the objective of concentrating light rather than forming an image, in addition to maximize the amount (energy) and quality (flux uniformity) of solar radiation, see for example the references. [1][2][3][4][5][6][7][8][9][10] An Aspheric Fresnel-type lens (for short AFL) consists of a series of adjacent microprisms designed to vary the angle of refraction by programming the angles of the flat surfaces of each of the prisms, either to collimate or focus incident light. 11,12 AFL have important properties since they reduce the thickness of the lens and less material is used in its construction producing lighter designs.…”

Section: Introductionmentioning

confidence: 99%

Design and fabrication of aspheric Fresnel-type lenses for solar energy by using a 3D printer

Jiménez-Rodríguez,

Avendaño-Alejo,

Ponce-Hernández

et al. 2024

Optical Fabrication and Testing VIII

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Traditionally, the Fresnel-type lens design often assumes thin lenses, since lenses of finite thickness cannot be completely described in analytical terms, then a numerical solution has to be found. We implement an exact ray trace considering a plane wavefront incident by reducing as much as possible the area of light concentration, while increasing the concentration ratio of energy. In such a way that we have mathematically determined a function to compute groove angles, to refract a bundle of rays from each planar echelon, which are propagated into a predetermined area of energy collection. In addition, we can evaluate the performance of the Fresnel-type lens design for a solar collector. Thus, an analytical formula to calculate the optical efficiency is obtained, in terms of the geometrical losses widely studied for nonimaging systems, such as blocking losses. Finally, the proposed aspherical Fresnel lens design is fabricated using a commercial 3D printer and subsequently polishing the surface for better performance. In this fashion we could test the performance of the manufactured prototype.

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Imaging performance of an ultra-precision machining-based Fresnel lens in ophthalmic devices

Cited by 12 publications

References 36 publications

A Review of Advances in Fabrication Methods and Assistive Technologies of Micro-Structured Surfaces

A Review of Advances in Fabrication Methods and Assistive Technologies of Micro-Structured Surfaces

Research on Virtual Reality Head-Mounted Displays based on MEMS Technology

Design and fabrication of aspheric Fresnel-type lenses for solar energy by using a 3D printer

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