Miniature adjustable-focus endoscope with a solid electrically tunable lens

Zou, Yongchao; Zhang, Wei; Chau, Fook Siong; Zhou, Guangya

doi:10.1364/oe.23.020582

Cited by 65 publications

(40 citation statements)

References 24 publications

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“…Zou et al employed two 6-order polynomials (Q = 6) to govern the two freeform surfaces independently, and achieved a diffraction-limited solid tunable lens. (49) Petsch et al further pointed out that the fourth-and sixth-order aberrations dominate the phase of the transmitted wavefront from the lens. Hence, they used the fifth-and seventh-order thickness terms in the polynomial (Q = 7) to compensate these aberrations and even-order terms to minimize the aberrations at the initial position.…”

Section: Optimum Design Of Solid Tunable Lensmentioning

confidence: 99%

See 1 more Smart Citation

Miniature Solid Tunable Lenses and Their Applications: A Review

Yongchao¹,

Siong²,

Guangya³

2017

Sensors and Materials

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We present a systematic review of solid tunable lenses based on the Alvarez-Lohmann principle, which mainly focuses on the optimization, miniaturization, and integration of such solid tunable lenses in miniature applications. The progress of the modelling and design methods of such solid tunable lenses for optimum performance is summarized first. The development of various solid tunable lenses achieved using diverse driving mechanisms and different optimization methods is then illustrated by examples from current literature. The mechanisms, performance, and practicability of all these prototypes are presented in detail. The applications of such solid tunable lenses in miniature imaging systems are finally reviewed. Discussions of the problems and bottlenecks encountered in current research work and perspectives for future work in this field are given.

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Section: Optimum Design Of Solid Tunable Lensmentioning

confidence: 99%

“…(49) As shown in Fig. 5, such an endoscope consists of a solid tunable lens for optical power tuning, two slender piezoelectric benders to laterally move the lens elements perpendicular to the optical axis, and an image fiber bundle for image transmission.…”

Section: Applications Of Solid Tunable Lenses In Miniature Imaging Symentioning

confidence: 99%

Miniature Solid Tunable Lenses and Their Applications: A Review

Yongchao¹,

Siong²,

Guangya³

2017

Sensors and Materials

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“…The lens elements are fabricated by the technology of single-point diamond turning followed by a standard polydimethylsioxane (PDMS) replication process [15][16][17][18]. As illustrated in Fig.…”

Section: Device Fabrication and Assemblymentioning

confidence: 99%

Miniature electrically tunable rotary dual-focus lenses

et al. 2016

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The emerging dual-focus lenses are drawing increasing attention recently due to their wide applications in both academia and industries, including laser cutting systems, microscopy systems, and interferometer-based surface profilers. In this paper, a miniature electrically tunable rotary dual-focus lens is developed. Such a lens consists of two optical elements, each having an optical flat surface and one freeform surface. The two freeform surfaces are initialized with the governing equation Ar 2 θ (A is the constant to be determined, r and θ denote the radii and angles in the polar coordinate system) and then optimized by ray tracing technique with additional Zernike polynomial terms for aberration correction. The freeform surfaces are achieved by a single-point diamond turning technique and then a PDMS-based replication process is utilized to materialize the final lens elements. To drive the two coaxial elements to rotate independently, two MEMS thermal rotary actuators are developed and fabricated by a standard MUMPs process. The experimental results show that the MEMS thermal actuator provides a maximum rotation angle of about 8.2 degrees with an input DC voltage of 6.5 V, leading to a wide tuning range for both the two focal lengths of the lens. Specifically, one focal length can be tuned from about 30 mm to 20 mm while the other one can be adjusted from about 30 mm to 60 mm.

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“…Compact lenses with tunable focal/imaging distance have many applications, and therefore several methods have been developed to make such devices [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] . Deformable solid and liquid-filled lenses with mechanical 1 , electromechanical 2,12 , electrowetting 9,10 , and thermal 11 tuning mechanisms have been demonstrated.…”

mentioning

confidence: 99%

“…Liquid crystal lenses with tunable focus [3][4][5] have higher tuning speeds, but they suffer from polarization dependence and limited tuning range. Freeform optical elements (e.g., Alvarez lenses) that can tune the focal distance upon lateral displacement of the elements have also been demonstrated 13,14 . These devices are generally based on mechanical movement of bulky elements and are therefore not very compact nor fast.…”

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confidence: 99%

MEMS-tunable dielectric metasurface lens

Arbabi

Kamali

et al. 2018

Conference on Lasers and Electro-Optics

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Varifocal lenses, conventionally implemented by changing the axial distance between multiple optical elements, have a wide range of applications in imaging and optical beam scanning. The use of conventional bulky refractive elements makes these varifocal lenses large, slow, and limits their tunability. Metasurfaces, a new category of lithographically defined diffractive devices, enable thin and lightweight optical elements with precisely engineered phase profiles. Here we demonstrate tunable metasurface doublets, based on microelectromechanical systems (MEMS), with more than 60 diopters (about 4%) change in the optical power upon a 1-μm movement of one metasurface, and a scanning frequency that can potentially reach a few kHz. They can also be integrated with a third metasurface to make compact microscopes (~1 mm thick) with a large corrected field of view (~500 μm or 40 degrees) and fast axial scanning for 3D imaging. This paves the way towards MEMSintegrated metasurfaces as a platform for tunable and reconfigurable optics.

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Miniature adjustable-focus endoscope with a solid electrically tunable lens

Cited by 65 publications

References 24 publications

Miniature Solid Tunable Lenses and Their Applications: A Review

Miniature Solid Tunable Lenses and Their Applications: A Review

Miniature electrically tunable rotary dual-focus lenses

MEMS-tunable dielectric metasurface lens

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