High-Flexibility Control of Structured Light with Combined Adaptive Optical Systems

Author(s):

Grunwald, Rüdiger; Jurke, Mathias; Bock, Martin; Liebmann, Max; Bruno, Binal Poyyathuruthy; Gowda, Hitesh & Wallrabe, Ulrike

Abstract:

“Combining the specific advantages of high-resolution liquid-crystal-on-silicon spatial light modulators (LCoS-SLMs) and reflective or refractive micro-electro-mechanical systems (MEMS) presents new prospects for the generation of structured light fields. In particular, adaptive self-apodization schemes can significantly reduce diffraction by low-loss spatial filtering. The concept enables one to realize low-dispersion shaping of nondiffracting femtosecond wavepackets and to temporally switch, modulate or deflect spatially structured beams. Adaptive diffraction management by structured illumination is demonstrated for piezo-based and thermally actuated axicons, spiral phase plates (SPPs) and Fresnel bi-mirrors. Improved non-collinear autocorrelation with angular-tunable Fresnel-bi-mirrors via self-apodized illumination and phase contrast of an SLM is proposed. An extension of the recently introduced nondiffractive Talbot effect to a tunable configuration by combining an SLM and a fluid lens is reported. Experimental results for hexagonal as well as orthogonal array beams are presented.”

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Publication: Photonics
Issue/Year: Photonics, Volume 9; Number 1; Pages 42; 2022
DOI: 10.3390/photonics9010042

Improving Multiphoton Microscopy by Combining Spherical Aberration Patterns and Variable Axicons

Author(s):

Bueno, J.M.; Hernández, G.; Skorsetz, M.; Artal, P.

Abstract:

“Multiphoton (MP) microscopy is a well-established method for the non-invasive imaging of biological tissues. However, its optical sectioning capabilities are reduced due to specimen-induced aberrations. Both the manipulation of spherical aberration (SA) and the use of axicons have been reported to be useful techniques to bypass this limitation. We propose the combination of SA patterns and variable axicons to further improve the quality of MP microscopy images. This approach provides enhanced images at different depth locations whose quality is better than those corresponding to the use of SA or axicons separately. Thus, the procedure proposed herein facilitates the visualization of details and increases the depth observable at high resolution.”

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Publication: Photonics
Issue/Year: Photonics, Volume 8; Number 12; Pages 573; 2021
DOI: 10.3390/photonics8120573

Distortion correction for wide angle holographic projector

Author(s):

Jędrzej Szpygiel, Maksymilian Chlipała, Rafał Kukołowicz, Moncy Idicula, Tomasz Kozacki

Abstract:

“This letter presents a distortion correction method enabling a distortion minimized, large size image in a wide angle holographic projector. The technique applies numerical predistortion of an input image used for hologram generation. It is based on estimation of distortion coefficients by comparing optically a reconstructed point test chart with the original one. Obtained experimental results prove that the technique allows reconstruction of high-quality image.”

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Publication: Photonics Letters of Poland
Issue/Year: Photonics Letters of Poland, Volume 13; Number 4; Pages 79; 2021
DOI: 10.4302/plp.v13i4.1125

Focusing light into scattering media with ultrasound-induced field perturbation

Author(s):

Cheng, Zhongtao & Wang, Lihong V.

Abstract:

“Focusing light into scattering media, although challenging, is highly desirable in many realms. With the invention of time-reversed ultrasonically encoded (TRUE) optical focusing, acousto-optic modulation was demonstrated as a promising guidestar mechanism for achieving noninvasive and addressable optical focusing into scattering media. Here, we report a new ultrasound-assisted technique, ultrasound-induced field perturbation optical focusing, abbreviated as UFP. Unlike in conventional TRUE optical focusing, where only the weak frequency-shifted first-order diffracted photons due to acousto-optic modulation are useful, here UFP leverages the brighter zeroth-order photons diffracted by an ultrasonic guidestar as information carriers to guide optical focusing. We find that the zeroth-order diffracted photons, although not frequency-shifted, do have a field perturbation caused by the existence of the ultrasonic guidestar. By detecting and time-reversing the differential field of the frequency-unshifted photons when the ultrasound is alternately ON and OFF, we can focus light to the position where the field perturbation occurs inside the scattering medium. We demonstrate here that UFP optical focusing has superior performance to conventional TRUE optical focusing, which benefits from the more intense zeroth-order photons. We further show that UFP optical focusing can be easily and flexibly developed into double-shot realization or even single-shot realization, which is desirable for high-speed wavefront shaping. This new method upsets conventional thinking on the utility of an ultrasonic guidestar and broadens the horizon of light control in scattering media. We hope that it provides a more efficient and flexible mechanism for implementing ultrasound-guided wavefront shaping.”

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Publication: Light: Science {&} Applications
Issue/Year: Light: Science {&} Applications, Volume 10; Number 1; 2021
DOI: 10.1038/s41377-021-00605-7

25D microscopy with polarization independent SLM for enhanced detection efficiency and aberration correction

Author(s):

Ren, Jinhan & Han, Kyu Young

Abstract:

“Fast, volumetric imaging by fluorescence microscopy is essential in studying bi-ological phenomena and cellular functions. Recently, single-shot 2.5D microscopy showedpromising results for high-throughput quantitative subcellular analysis via extended depth offield imaging without sequentialz-scanning; however, the detection efficiency was limited and itlacked depth-induced aberration correction. Here we report that a spatial light modulator (SLM)in a polarization insensitive configuration can significantly improve the detection efficiency of2.5D microscopy, while also compensating for aberrations at large imaging depths caused bythe refractive index mismatch between the sample and the immersion medium. We highlightthe improved efficiency via quantitative single-molecule RNA imaging of mammalian cellswith a 2-fold improvement in the fluorescence intensity compared to a conventional SLM-basedmicroscopy. We demonstrate the aberration correction capabilities and extended depth of field byimaging thick specimens with fewerz-scanning steps.”

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Publication: Optics Express
Issue/Year: Optics Express, Volume 29; Number 17; Pages 27530; 2021
DOI: 10.1364/oe.434260

Experimental analysis of adaptive optics correction methods on the beam carrying orbital angular momentum mode through oceanic turbulence

Author(s):

Zhan, Haichao; Wang, Le; Wang, Wennai & Zhao, Shengmei

Abstract:

“In recent years, as the demand for underwater communication has increased, underwater wireless optical communication (UWOC) has attracted a lot of attentions. Meanwhile, orbital angular momentum (OAM) has been applied in UWOC system to increase communication link capacity. However, the aberrations caused by oceanic turbulence (OT) is unavoidable, which results in serious intermodal crosstalk. Usually, adaptive optics (AO) is used to compensate these distortion aberrations. In this work, we experimentally demonstrate the influence of the distortion caused by OT, and evaluate the performance of AO correction algorithms, including Shack-Hartmann (SH), Stochastic-Parallel-Gradient-Descent (SPGD) and Gerchberg-Saxton (GS) algorithms. During the experiment, OT is simulated by using improved random phase screen model. We discuss the influence of various parameters of OT, including relative strength of temperature and salinity, strength of OT , and propagation distance, on the compensation effect with and without correction algorithms. The results show that all the three AO algorithms have good compensation effect on the distortion caused by OT, and GS algorithm has a better capability than the other two algorithms. Additionally, when the iteration numbers is less than 100, the compensation effect of GS and SPGD algorithms becomes more obvious as the iteration numbers increases, and GS algorithm is superior to SPGD algorithm. This work is beneficial to aberration correction of OAM-based UWOC system.”

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Publication: Optik
Issue/Year: Optik, Volume 240; Pages 166990; 2021
DOI: 10.1016/j.ijleo.2021.166990

Thermal blooming induced phase change and its compensation of a Gaussian beam propagation in an absorbing medium

Author(s):

Lu, Lu; Wang, Zhiqiang; Zhang, Pengfei; Qiao, Chunhong & Cai, Yangjian

Abstract:

“A high-power laser beam propagating in an absorbing medium, thermal blooming causes phase distortion, which is severe for the beam quality. In this Letter, a feasible approach for obtaining the phase change induced by thermal blooming is proposed. In addition, based on the aforementioned phase change, an alternative solution of phase compensation near the receiver is provided, which may enrich the previous compensation method (i.e., using an adaptive optics system near the beam transmitter). These findings may have potential applications in optical communication, astronomical imaging, and related areas.”

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Publication: Optics Letters
Issue/Year: Optics Letters, Volume 46; Number 17; Pages 4304; 2021
DOI: 10.1364/ol.437851

Vision-correcting Holographic Display: Evaluation of Aberration Correcting Hologram

Author(s):

Kim, Dongyeon; Nam, Seung-Woo; Bang, Kiseung; Lee, Byounghyo; Lee, Seungjae; Jeong, Youngmo; Seo, Jongmo & Lee, Byoungho

Abstract:

“Vision-correcting displays are key to achieving physical and physiological comforts to the users with refractive errors. Among such displays are holographic displays, which can provide a high-resolution vision-adaptive solution with complex wavefront modulation. However, none of the existing hologram rendering techniques have considered the optical properties of the human eye nor evaluated the significance of vision correction. Here, we introduce vision-correcting holographic display and hologram acquisition that integrates user-dependent prescriptions and a physical model of the optics, enabling the correction of on-axis and off-axis aberrations. Experimental and empirical evaluations of the vision-correcting holographic displays show the competence of holographic corrections over the conventional vision correction solutions.”

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Publication: Biomedical Optics Express
Issue/Year: Biomedical Optics Express,Vol. 12, Issue 8, pp. 5179-5195, 2021
DOI: 10.1364/boe.433919

Control of femtosecond single-filament formation via feedback-based wavefront shaping

Author(s):

Li, Jing; Tan, Wenjiang; Si, Jinhai; Tang, Shiyun; Kang, Zhen & Hou, Xun

Abstract:

“We demonstrate the control of femtosecond single-filament formation via feedback-based wavefront shaping. It is observed that the optimal phase profile forms a single-filament with closed-loop genetic algorithm. Using this method, the position stability of the filament can be significantly improved, and the position of the single filament can be flexibly adjusted. Additionally, a two-step approach combining the premodulation of pinhole with wavefront shaping is presented for forming a bright single filament rapidly.”

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Publication: Optics Communications
Issue/Year: Optics Communications, Volume 490; Pages 126929; 2021
DOI: 10.1016/j.optcom.2021.126929

Single-shot digital multiplexed holography for the measurement of deep shapes

Author(s):

Kozacki, Tomasz; Mikuła-Zdańkowska, Marta; Martinez-Carranza, Juan & Idicula, Moncy Sajeev

Abstract:

“This work develops a single-shot holographic profilometer that enables shape characterization of discontinuous deep surfaces. This is achieved by combining hologram frequency multiplexing and an illumination technique of complex amplitude in multi-incidence angle profilometer. Object illumination is carried out from seven directions simultaneously, where the radial angular coordinates of illumination plane waves obey the geometric series. It is shown that: (i) the illumination pattern provides the required frequency separation of all object wavefronts in transverse frequency space, which is necessary for hologram demultiplexing, and (ii) numerical generation of longitudinal scanning function (LSF) is possible, which has large measurement range, high axial resolution, and small side lobes. Low side lobes of LSF and the developed multiplexed field dependent aberration compensation method are essential to minimize the negative influence of speckle noise of single-shot capture on the measurement result. The utility of the proposed method is demonstrated with experimental measurement of heights of two step-like objects.”

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Publication: Optics Express
Issue/Year: Optics Express, Volume 29; Number 14; Pages 21965; 2021
DOI: 10.1364/oe.428419
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