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Lv J, Hong H, Gan Z, Zhang M, Liu Z, Hu Z. Dielectric elastomer-driven liquid prism enabling two-dimensional beam control. OPTICS EXPRESS 2024; 32:21517-21531. [PMID: 38859504 DOI: 10.1364/oe.525455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Accepted: 05/12/2024] [Indexed: 06/12/2024]
Abstract
In this paper, a dielectric elastomer (DE)-driven liquid prism enabling two-dimensional beam control is proposed. The proposed liquid prism consists of a flexible driver and a liquid cavity. The glass plate is driven by DE to change the tilt angle of the liquid-solid interface for beam steering and field of view (FOV) tuning. The maximum optical deflection angle of 8.13° and response time of 76.77 ms were measured, the variable FOV capability was also verified. The proposed liquid prism can be used in beam modulation, microscope systems.
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2
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Bi Z, Diao Z, Wang Y, Chen A, Zhao H, Liu Y, Peng Z, Yang C, Li D, Mu Q. Study on dynamic response characteristics of the scanning angle in a liquid crystal cladding waveguide beam scanner. OPTICS EXPRESS 2024; 32:20339-20349. [PMID: 38859147 DOI: 10.1364/oe.527257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Accepted: 05/07/2024] [Indexed: 06/12/2024]
Abstract
This paper studies the dynamic response characteristics of the scanning angle in a liquid crystal cladding waveguide beam scanner. Based on liquid crystal dynamic theory, finite element analysis and vectorial refraction law, a dynamic response calculation model of scanning angle is constructed. The simulation results show that the dynamic responses of the scanning angle during the electric field-on and field-off processes are asymmetric, and exhibit "S"-shape and "L"-shape changing trends, respectively. In addition, by comparing with the bulk phase modulation response process of traditional liquid crystal devices, the intrinsic physical reason for the rapid light regulation of the liquid crystal cladding waveguide beam scanner is clarified to be that the liquid crystal close to the core layer has a faster rotation speed during the electric field-off process. Moreover, the liquid crystal cladding waveguide beam scanner is experimentally tested, and the experiment results are in good agreement with theoretical simulations.
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3
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Gilinsky SD, Jung DN, Futia GL, Zohrabi M, Welton TA, Supekar OD, Gibson EA, Restrepo D, Bright VM, Gopinath JT. Tunable liquid lens for three-photon excitation microscopy. BIOMEDICAL OPTICS EXPRESS 2024; 15:3285-3300. [PMID: 38855666 PMCID: PMC11161341 DOI: 10.1364/boe.516956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 03/28/2024] [Accepted: 04/06/2024] [Indexed: 06/11/2024]
Abstract
We demonstrate a novel electrowetting liquid combination using a room temperature ionic liquid (RTIL) and a nonpolar liquid, 1-phenyl-1-cyclohexene (PCH) suitable for focus-tunable 3-photon microscopy. We show that both liquids have over 90% transmission at 1300 nm over a 1.1 mm pathlength and an index of refraction contrast of 0.123. A lens using these liquids can be tuned from a contact angle of 133 to 48° with applied voltages of 0 and 60 V, respectively. Finally, a three-photon imaging system including an RTIL electrowetting lens was used to image a mouse brain slice. Axial scans taken with an electrowetting lens show excellent agreement with images acquired using a mechanically scanned objective.
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Affiliation(s)
- Samuel D. Gilinsky
- Department of Electrical, Computer, and Energy Engineering, University of Colorado Boulder, Boulder, Colorado 80309, USA
| | - Diane N. Jung
- Department of Mechanical Engineering, University of Colorado Boulder, Boulder, Colorado 80309, USA
| | - Greg L. Futia
- Department of Bioengineering, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Mo Zohrabi
- Department of Electrical, Computer, and Energy Engineering, University of Colorado Boulder, Boulder, Colorado 80309, USA
| | - Tarah A. Welton
- Department of Bioengineering, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Omkar D. Supekar
- Department of Electrical, Computer, and Energy Engineering, University of Colorado Boulder, Boulder, Colorado 80309, USA
| | - Emily A. Gibson
- Department of Bioengineering, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Diego Restrepo
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Victor M. Bright
- Department of Mechanical Engineering, University of Colorado Boulder, Boulder, Colorado 80309, USA
| | - Juliet T. Gopinath
- Department of Electrical, Computer, and Energy Engineering, University of Colorado Boulder, Boulder, Colorado 80309, USA
- Department of Physics, University of Colorado Boulder, Boulder, Colorado 80309, USA
- Materials Science and Engineering Program, University of Colorado Boulder, Boulder, Colorado 80309, USA
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4
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Baker JL, Lang KA, Dickensheets DL, Nakagawa W. Demonstration of a compact double-reflection transmissive beam scanner operating at 1550 nm wavelength. APPLIED OPTICS 2024; 63:1429-1437. [PMID: 38437324 DOI: 10.1364/ao.514908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 01/12/2024] [Indexed: 03/06/2024]
Abstract
A compact forward-directed transmissive beam scanner operating at a wavelength of 1550 nm was constructed and characterized. The scanner consists of two wire-grid polarizers (WGPs) surrounding a 45° Faraday rotator, causing incident light to reflect once from each WGP before transmitting through the second polarizer. Scanning is achieved by tilting one of the WGPs. Measured efficiency remained above 73% over a 90° forward scan range (-45∘ to +45∘) for vertically polarized incident light. Additionally, we measured the efficiency versus beam deflection for four different incident linear polarization configurations, three of which maintained >70% efficiency for deflection angles up to -60∘.
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5
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Sieben M, Sauter D, Zappe H. Phase retrieval for the generation of arbitrary intensity distributions using an optofluidic phase shifter. OPTICS EXPRESS 2023; 31:36000-36011. [PMID: 38017759 DOI: 10.1364/oe.496598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 08/20/2023] [Indexed: 11/30/2023]
Abstract
An optofluidic phase shifter can be used to generate virtually arbitrary intensity patterns, but only if the phase shift generated by the controllably deformed fluidic surface can be appropriately defined. To enable this functionality, we present two phase retrieval algorithms based on neural networks and least-squares optimization which are used to determine the necessary phase profile to generate a desired target intensity pattern with high accuracy. We demonstrate the utility of the algorithms by showing experimentally the ability of an optofluidic phase shifter to generate arbitrary complex intensity distributions.
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6
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Gilinsky SD, Zohrabi M, Lim WY, Supekar OD, Bright VM, Gopinath JT. Fabrication and characterization of a two-dimensional individually addressable electrowetting microlens array. OPTICS EXPRESS 2023; 31:30550-30561. [PMID: 37710595 PMCID: PMC10544957 DOI: 10.1364/oe.497992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 08/08/2023] [Accepted: 08/11/2023] [Indexed: 09/16/2023]
Abstract
We demonstrate a two-dimensional, individually tunable electrowetting microlens array fabricated using standard microfabrication techniques. Each lens in our array has a large range of focal tunability from -1.7 mm to -∞ in the diverging regime, which we verify experimentally from 0 to 75 V for a device coated in Parylene C. Additionally, each lens can be actuated to within 1% of their steady-state value within 1.5 ms. To justify the use of our device in a phase-sensitive optical system, we measure the wavefront of a beam passing through the center of a single lens in our device over the actuation range and show that these devices have a surface quality comparable to static microlens arrays. The large range of tunability, fast response time, and excellent surface quality of these devices open the door to potential applications in compact optical imaging systems, transmissive wavefront shaping, and beam steering.
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Affiliation(s)
- Samuel D. Gilinsky
- Department of Electrical, Computer and Energy Engineering, University of Colorado Boulder, Boulder, CO 80309, USA
| | - Mo Zohrabi
- Department of Electrical, Computer and Energy Engineering, University of Colorado Boulder, Boulder, CO 80309, USA
| | - Wei Yang Lim
- Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO 80309, USA
| | - Omkar D. Supekar
- Department of Electrical, Computer and Energy Engineering, University of Colorado Boulder, Boulder, CO 80309, USA
| | - Victor M. Bright
- Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO 80309, USA
| | - Juliet T. Gopinath
- Department of Electrical, Computer and Energy Engineering, University of Colorado Boulder, Boulder, CO 80309, USA
- Department of Physics, University of Colorado Boulder, Boulder, CO 80309, USA
- Materials Science and Engineering Program, University of Colorado Boulder, Boulder, CO 80309, USA
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7
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Li L, Xie N, Li JQ, Fu JY, Liu SB, Wang LH, Li YH, Li L. Optofluidic zoom system with increased field of view and less chromatic aberration. OPTICS EXPRESS 2023; 31:25117-25127. [PMID: 37475324 DOI: 10.1364/oe.498096] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 07/05/2023] [Indexed: 07/22/2023]
Abstract
Imaging systems are widely used in many fields. However, there is an inherent compromise between field of view (FOV) and resolution. In this paper, we propose an optofluidic zoom system with increased FOV and less chromatic aberration, which can realize switching between large FOV and high resolution. The proposed system consists of a liquid prism, a zoom objective, an image sensor and image processing module, which can realize optical zoom and deflection. The proposed system achieves non-mechanical optical zoom from f = 40.5 mm to f = 84.0 mm. Besides, the angular resolution of zoom objective is up to 26"18 at f = 84.0 mm. The deflection range is ±10°, and the whole FOV of proposed system can reach up to 30.3°. The proposed system is compact and easy to machine. In addition, we reduce chromatic aberration produced by the liquid prism significantly. The proposed system can be used in monitor system, target tracking system, telescope system and so on.
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Miscles EJ, Lim WY, Supekar OD, Zohrabi M, Gopinath JT, Bright VM. Axisymmetrical resonance modes in an electrowetting optical lens. APPLIED PHYSICS LETTERS 2023; 122:201106. [PMID: 37214761 PMCID: PMC10195114 DOI: 10.1063/5.0141787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 04/29/2023] [Indexed: 05/24/2023]
Abstract
Electrowetting-based adaptive optics are of great interest for applications ranging from confocal microscopy to LIDAR, but the impact of low-frequency mechanical vibration on these devices remains to be studied. We present a simple theoretical model for predicting the resonance modes induced on the liquid interface in conjunction with a numerical simulation. We experimentally confirm the resonance frequencies by contact angle modulation. They are found to be in excellent agreement with the roots of the zero-order Bessel functions of the first kind. Next, we experimentally verify that external axial vibration of an electrowetting lens filled with density mismatched liquids (Δρ = 250 kg/m3) will exhibit observable Bessel modes on the liquid-liquid interface. An electrowetting lens filled with density matched liquids (Δρ = 4 kg/m3) is robust to external axial vibration and is shown to be useful in mitigating the effect of vibrations in an optical system.
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Affiliation(s)
- Eduardo J. Miscles
- Department of Mechanical Engineering, University of Colorado, Boulder, Colorado 80309, USA
| | - Wei Yang Lim
- Department of Mechanical Engineering, University of Colorado, Boulder, Colorado 80309, USA
| | | | - Mo Zohrabi
- Department of Electrical, Computer, and Energy Engineering, University of Colorado, Boulder, Colorado 80309, USA
| | | | - Victor M. Bright
- Department of Mechanical Engineering, University of Colorado, Boulder, Colorado 80309, USA
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Wei X, Zhao R, Liang Z, Kong M, Chen T. Design, fabrication, and characterization of an optofluidic phase modulator array based on the piezoelectric effect. OPTICS LETTERS 2022; 47:1315-1318. [PMID: 35290302 DOI: 10.1364/ol.452611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 02/15/2022] [Indexed: 06/14/2023]
Abstract
In this paper, an optofluidic phase modulator array based on the piezoelectric effect is designed, fabricated, and characterized. This array is composed of three piezoelectric ceramics arranged on the vertices of an equilateral triangle. A transparent liquid fills the inner cavity of the ceramics. Due to the inverse piezoelectric effect, the length of the transparent liquid is changed at different voltages, which contributes to the optical phase modulation. According to experiment results, it is found that our modulator arrays exert continuous optical phase adjustment ability. When the voltage ranges from 0 to 135 V, the relative length variation reaches up to 9.286 µm, and consequently our proposed modulator arrays perform about 9.685 π optical phase modulation.
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Wadhai SM, Sawane YB, Limaye AV, Banpurkar AG. Large tuning in the electrowetting behaviour on ferroelectric PVDF-HFP/Teflon AF bilayer. JOURNAL OF MATERIALS SCIENCE 2021; 56:16158-16166. [PMID: 34276067 PMCID: PMC8274264 DOI: 10.1007/s10853-021-06308-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 06/30/2021] [Indexed: 06/13/2023]
Abstract
Electrowetting (EW) response on a dielectric depends on its permittivity value, Young contact angle and voltage amplitude. We present a large change in EW contact angle, from 163° to 80°, on the bilayer dielectric made up of ferroelectric PVDF-HFP with a thin layer of fluoropolymer. The thickness values of both layers were separately optimized for high effective capacitance essential for the large EW response. It reveals that the bilayer with ~ 500 nm thick PVDF-HFP layer and ~ 50 nm thin layer of Teflon results in the maximum value of effective dielectric constant, ε ≈ 8. Besides this gain, dc-voltage EW response exhibits hysteresis mainly due to polarization in the ferroelectric layer such that, hysteretic offset voltage was found to depend on the applied voltage amplitude and thickness of the dielectrics. Finally, bilayer was subjected to ac-voltage EW in silicone oil for ambient temperature ranging from - 25 to 70 °C. The consistent EW response in this ambient without any degradation/delamination of polymer surface confirmed the durability of the bilayer on the transparent ITO electrodes. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s10853-021-06308-z.
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Affiliation(s)
- Sandip M. Wadhai
- Department of Physics, Centre for Advanced Studies in Materials Science and Condensed Matter Physics, Savitribai Phule Pune University, Pune, 411007 India
| | - Yogesh B. Sawane
- Department of Physics, Ahmednagar College, Ahmednagar, 414 001 India
| | - Abhay. V. Limaye
- Department of Physics, Centre for Advanced Studies in Materials Science and Condensed Matter Physics, Savitribai Phule Pune University, Pune, 411007 India
| | - Arun G. Banpurkar
- Department of Physics, Centre for Advanced Studies in Materials Science and Condensed Matter Physics, Savitribai Phule Pune University, Pune, 411007 India
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11
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Zhao P, Li Y, Zappe H. Accelerated electrowetting-based tunable fluidic lenses. OPTICS EXPRESS 2021; 29:15733-15746. [PMID: 33985269 DOI: 10.1364/oe.423460] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 04/02/2021] [Indexed: 06/12/2023]
Abstract
One of the limitations in the application of electrowetting-based tunable fluidic lenses is their slow response time. We consider here two approaches for enhancing the response speed of tunable fluidic lenses: optimization of the properties of the fluids employed and modification of the time-dependent actuation voltages. Using a tubular optofluidic configuration, it is shown through simulations how one may take advantage of the interplay between liquid viscosities and surface tension to reduce the actuation time. In addition, by careful designing the actuation pulses, the response speed of both overdamped and underdamped systems may be increased by over an order of magnitude, leading to response times of several ten milliseconds. These performance improvements may significantly enhance the applicability of tunable optofluidic-based components and systems.
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12
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Kallmann U, Lootze M, Mescheder U. Simulative and Experimental Characterization of an Adaptive Astigmatic Membrane Mirror. MICROMACHINES 2021; 12:mi12020156. [PMID: 33562530 PMCID: PMC7915456 DOI: 10.3390/mi12020156] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 02/02/2021] [Accepted: 02/02/2021] [Indexed: 11/16/2022]
Abstract
Adaptive optical (AO) components play an important role in numerous optical applications, from astronomical telescopes to microscope imaging systems. For most of these AO components, the induced wavefront correction, respectively added optical power, is based on a rotationally symmetric or segmented design of the AO component. In this work, we report on the design, fabrication, and characterization of a micro-electronic-mechanical system (MEMS) adaptive membrane mirror in the shape of a parabolic cylinder. In order to interpret the experimental characterization results correctly and provide a tool for future application development, this is accompanied by the setup of an optical simulation model. The characterization results showed a parabolically deformable membrane mirror with an aperture of 8 × 2 mm2 and an adaptive range for the optical power from 0.3 to 6.1 m−1 (dpt). The optical simulation model, using the Gaussian beamlet propagation method, was successfully validated by laser beam profile measurements taken in the optical characterization setup. This MEMS-based adaptive astigmatic membrane mirror, together with the accompanying simulation model, could be a key component for the rapid development of new optical systems, e.g., adaptive laser line generators.
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Affiliation(s)
- Ulrich Kallmann
- Department of Business Admin & Engineering, Furtwangen University of Applied Science, D-78120 Furtwangen, Germany
- Correspondence:
| | - Michael Lootze
- Institute for Microsystems Technology (IMST), Department of Mechanical & Medical Engineering, Furtwangen University of Applied Science, D-78120 Furtwangen, Germany; (M.L.); (U.M.)
| | - Ulrich Mescheder
- Institute for Microsystems Technology (IMST), Department of Mechanical & Medical Engineering, Furtwangen University of Applied Science, D-78120 Furtwangen, Germany; (M.L.); (U.M.)
- Associated to the Faculty of Engineering, University of Freiburg, D-79110 Freiburg, Germany
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13
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Lee J, Lee J, Won YH. Image stitching using an electrowetting-based liquid prism with a fabrication method. OPTICS EXPRESS 2021; 29:729-739. [PMID: 33726303 DOI: 10.1364/oe.414236] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 12/11/2020] [Indexed: 06/12/2023]
Abstract
In this paper, we propose a new method for image stitching using an electrowetting-based liquid prism. Several images were obtained by adjusting the voltages applied to four sidewalls of the liquid prism, and a panoramic image was achieved through an image stitching algorithm. The relationship between the tilting angle of the liquid prism and the normal vector of the liquid-liquid interface was presented. Novel fabrication method has been proposed to improve the performance of the liquid prism, including the addition of a new structure to prevent oil isolation, plastic chamber material, plastic laser cutting, and oil selection. The fabricated liquid prism has a size of 5 × 5 × 8 mm, a maximum beam steering angle of ±10.5 °, a response time of 19.1 ms, and a resolution of 14.25 lp/mm. The required number of images according to the overlapping area was presented through the simulation, and the image stitching using two or three images was demonstrated.
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Zhang W, Zhao R, He Y, Ding W, Liang Z, Kong M, Chen T. Electrowetting-actuated optofluidic phase modulator. OPTICS EXPRESS 2021; 29:797-804. [PMID: 33726308 DOI: 10.1364/oe.406140] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 10/19/2020] [Indexed: 06/12/2023]
Abstract
In this paper, an optofluidic phase modulator based on electrowetting is presented. The modulator consists of an inner and outer chamber. Two immiscible liquids are filled into the chambers, and a transparent sheet is fixed between the liquid-liquid interface to obtain a flat interface. By applying different voltages to the modulator, the flat interface moves up and down leading to the change of optical path length. Consequently, the variation of the optical path in the proposed modulator exploits the ability to alter the optical phase. To prove the concept, a prototype of the phase modulator is fabricated in experiment, and the ability of phase modulation is detected. Our proposed modulator performs optical phase shift up to ∼6.68 π driven with 150 V. Widespread applications of such an optofluidic phase modulator is foreseeable.
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Lim WY, Zohrabi M, Gopinath JT, Bright VM. Calibration and characteristics of an electrowetting laser scanner. IEEE SENSORS JOURNAL 2020; 20:3496-3503. [PMID: 33746623 PMCID: PMC7977153 DOI: 10.1109/jsen.2019.2959792] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We present a calibration method to correct for fabrication variations and optical misalignment in a two-dimensional electrowetting scanner. These scanners are an attractive option due to being transmissive, nonmechanical, having a large scan angle (±13.7°), and low power consumption (μW). Fabrication imperfections lead to non-uniform deposition of the dielectric or hydrophobic layer which results in actuation inconsistency of each electrode. To demonstrate our calibration method, we scan a 5 × 5 grid target using a four-electrode electrowetting prism and observe a pincushion type optical distortion in the imaging plane. Zemax optical simulations verify that the symmetric distortion is due to the projection of a radial scanning surface onto a flat imaging plane, while in experiment we observe asymmetrical distortion due to optical misalignment and fabrication imperfections. By adjusting the actuation voltages through an iterative Delaunay triangulation interpolation method, the distortion is corrected and saw an improvement in the mean error across 25 grid points from 43 μm (0.117°) to 10 μm (0.027°).
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Affiliation(s)
- Wei Yang Lim
- Department of Mechanical Engineering, University of Colorado, Boulder, CO, 80309 USA
| | - Mo Zohrabi
- Department of Electrical Engineering, University of Colorado, Boulder, CO 80309 USA
| | - Juliet T Gopinath
- Department of Electrical Engineering and Department of Physics, University of Colorado, Boulder, CO 80309 USA
| | - Victor M Bright
- Department of Mechanical Engineering, University of Colorado, Boulder, CO, 80309 USA
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16
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Zohrabi M, Yang Lim W, Bright VM, Gopinath JT. High extinction ratio, low insertion loss, optical switch based on an electrowetting prism. OPTICS EXPRESS 2020; 28:5991-6001. [PMID: 32225857 PMCID: PMC7347523 DOI: 10.1364/oe.381565] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 01/09/2020] [Accepted: 01/11/2020] [Indexed: 05/13/2023]
Abstract
An optical switch based on an electrowetting prism coupled to a multimode fiber has demonstrated a large extinction ratio with speeds up to 300 Hz. Electrowetting prisms provide a transmissive, low power, and compact alternative to conventional free-space optical switches, with no moving parts. The electrowetting prism performs beam steering of ±3° with an extinction ratio of 47 dB between the ON and OFF states and has been experimentally demonstrated at scanning frequencies of 100-300 Hz. The optical design is modeled in Zemax to account for secondary rays created at each surface interface (without scattering). Simulations predict 50 dB of extinction, in good agreement with experiment.
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Affiliation(s)
- Mo Zohrabi
- Department of Electrical, Computer, and Energy Engineering, University of Colorado, Boulder, Colorado 80309, USA
| | - Wei Yang Lim
- Department of Mechanical Engineering, University of Colorado, Boulder, Colorado 80309, USA
| | - Victor M. Bright
- Department of Mechanical Engineering, University of Colorado, Boulder, Colorado 80309, USA
| | - Juliet T. Gopinath
- Department of Electrical, Computer, and Energy Engineering, University of Colorado, Boulder, Colorado 80309, USA
- Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
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17
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Lee J, Lee J, Won YH. Nonmechanical three-dimensional beam steering using electrowetting-based liquid lens and liquid prism. OPTICS EXPRESS 2019; 27:36757-36766. [PMID: 31873449 DOI: 10.1364/oe.27.036757] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 11/15/2019] [Indexed: 06/10/2023]
Abstract
In this paper, we present a system for nonmechanical three-dimensional beam steering using an electrowetting based liquid lens and liquid prism. The optical design of the presented system was modeled with Zemax and three-dimensional beam steering was simulated by changing the ROC of the lens and the apex angle of the prism. The liquid lens from Corning-Varioptic was used and the liquid prism was fabricated and these were combined. The liquid lens and liquid prism were filled with two immiscible liquids whose densities are the same. The liquid lens provides variable focal lengths as the applied voltage is changed. The diopter range of the liquid lens is from -3.9 D to 14.5 D. Beam steering on the x-axis, y-axis, and xy-axis was achieved by applying different voltages to four sidewalls of the liquid prism. The liquid prism has a beam steering angle of up to 11.6 °, 12 °, and 11.8 ° on x-axis, y-axis, and xy-axis, respectively. By combining the electrowetting actuated liquid lens and liquid prism, three-dimensional beam steering control including the z-axis direction was demonstrated.
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Castillón M, Palomer A, Forest J, Ridao P. State of the Art of Underwater Active Optical 3D Scanners. SENSORS 2019; 19:s19235161. [PMID: 31775354 PMCID: PMC6928952 DOI: 10.3390/s19235161] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 11/18/2019] [Accepted: 11/21/2019] [Indexed: 12/28/2022]
Abstract
Underwater inspection, maintenance and repair (IMR) operations are being increasingly robotized in order to reduce safety issues and costs. These robotic systems rely on vision sensors to perform fundamental tasks, such as navigation and object recognition and manipulation. Especially, active optical 3D scanners are commonly used due to the domain-specific challenges of underwater imaging. This paper presents an exhaustive survey on the state of the art of optical 3D underwater scanners. A literature review on light projection and light-sensing technologies is presented. Moreover, quantitative performance comparisons of underwater 3D scanners present in the literature and commercial products are carried out.
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19
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Li C, Cao X, Wu K, Li X, Chen J. Lens-based integrated 2D beam-steering device with defocusing approach and broadband pulse operation for Lidar application. OPTICS EXPRESS 2019; 27:32970-32983. [PMID: 31878372 DOI: 10.1364/oe.27.032970] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 10/21/2019] [Indexed: 05/20/2023]
Abstract
We propose an integrated two-dimensional beam-steering device based on an on-chip silicon-nitride switch/emitter structure and off-chip lens for light detection and ranging (Lidar) application at 1550 nm. In this device, light is guided by a 1 × 16 switch to one grating emitter in a 4 × 4 grating-emitter array. The beam from the grating emitter is collimated and steered by a fixed lens. By changing the grating emitter that emits light, different beam-steering angle can be achieved. A divergence angle of 0.06° and a field of view of 2.07° × 4.12° in the far field are achieved. The device has O(log2N) power consumption for N emitters, allows digital control and achieves 18 dB background suppression. Blind-zone elimination and broadband operation are also achieved in our lens-based beam-steering device. Therefore, it is suitable for broadband solid-state Lidar application.
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