Mr. Daniel J. Wahl Profile

Daniel J. Wahl

Optical Systems Development Engineer at Lumentum

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Author

Publications (14)

Proceedings Article | 19 July 2019 Paper

Real time volumetric region of interest tracking for sensorless adaptive optics retinal imaging

Daniel Wahl, Ringo Ng, Joey Huang, Worawee Janpongsri, Marinko Sarunic, Yifan Jian

Proceedings Volume 11078, 110780L (2019) https://doi.org/10.1117/12.2527518

KEYWORDS: Optical coherence tomography, Adaptive optics, Imaging systems, Retina, Scanning laser ophthalmoscopy, Retinal scanning, Sensors, Luminescence, Mirrors, Confocal microscopy

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Proceedings Article | 19 July 2019 Paper

Sensorless adaptive optics optical coherence tomography for two photon excited fluorescence mouse retinal imaging

Daniel Wahl, Myeong Jin Ju, Yifan Jian, Marinko Sarunic

Proceedings Volume 11078, 110781L (2019) https://doi.org/10.1117/12.2527203

KEYWORDS: Optical coherence tomography, Retinal scanning, Retina, Aberration correction, Eye, Adaptive optics, Sensors, Two photon excitation microscopy, Imaging systems

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Two-Photon Excited Fluorescence (TPEF) is a common modality for volumetric imaging within a biological sample. The molecule-specific contrast of TPEF imaging of the retina enables novel in vivo studies of disease and retina physiology. Furthermore, retinal studies can be aided by imaging the relevant cells, which can be fluorescently labelled with fluorophores such as GFP. The multiphoton absorption suppresses the out-of-focus background signal and improves with the axial sectioning without a confocal aperture in the optical detection path. Imaging the retina with near infrared (NIR) light is ideal since the retina contain visual pigments that are sensitive to visible wavelengths and NIR light has less scattering within biological tissue than shorter wavelengths. However, high pulse energy is required to generate the TPEF, yet minimizing the incident exposure energy is required for non-invasive imaging. TPEF signal intensity increases quartically with the spot size, which leads to high sensitivity to aberrations that distribute the energy deposition of the focused light¹. For retinal imaging, decreasing the spot size requires the imaging beam to fill a larger area of the eye, which corresponds to an increase in the aberration amplitudes and often results in low TPEF. Recent research has demonstrated improvements to the TPEF signal for retinal imaging using AO for aberrations correction^2,3,4.

Theoretically, the numerical aperture through the pupil of the mouse eye permits sub-micrometer imaging of the retina. However, optical aberrations introduced by the tear film, cornea and intraocular lens reduce the actual resolution. In order to approach diffraction limited imaging, these aberrations can be corrected with Adaptive Optics (AO) using a wavefront corrector such as Deformable Mirror (DM). The traditional approach to AO is to use a Wavefront Sensor (WFS) to measure the ocular aberrations directly. Performing accurate wavefront measurements for WFS AO imaging in a small animal eye requires a high system complexity due to the short length of the eye creating an optically thick sample with multiple scattering surfaces. Alternatively, Sensorless AO (SAO) has the potential to overcome the limitations of the SH-WFS. SAO does not require direct measurement of the optical wavefront but instead uses an image-based approach. SAO methods have the ability to provide depth resolved aberration correction by performing the aberration correction at different layers within the retina.

Our imaging system provides volumetric TPEF imaging in the retina using SAO-OCT for depth-specific aberration correction, using same light source to generate the OCT and TPEF. Here, we present our progress since our previous report4 with improvements to the light delivery, aberration correction, and TPEF detection.

Proceedings Article | 4 March 2019 Presentation

Multi-scale and -mode sensorless adaptive optics OCT for in vivo human retinal imaging (Conference Presentation)

JiHoon Kwon, Destiny Hsu, Myeong Jin Ju, Daniel Wahl, Yifan Jian, Marinko Sarunic

Proceedings Volume 10867, 1086721 (2019) https://doi.org/10.1117/12.2510995

KEYWORDS: Optical coherence tomography, Retinal scanning, Imaging systems, Sensors, Adaptive optics, In vivo imaging, Polarization, Collimators, Phase interferometry, Calibration

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Proceedings Article | 18 March 2018 Paper

Adaptive optics with combined optical coherence tomography and scanning laser ophthalmoscopy for in vivo mouse retina imaging

Pengfei Zhang, Daniel Wahl, Jacopo Mocci, Suman Manna, Ratheesh Meleppat, Stefano Bonora, Marinko Sarunic, Edward Pugh, Robert Zawadzki

Proceedings Volume 10474, 1047427 (2018) https://doi.org/10.1117/12.2288607

KEYWORDS: Optical coherence tomography, Scanning laser ophthalmoscopy, Adaptive optics, Data acquisition, Retinal scanning, Retina, Imaging systems, Wavefront sensors, In vivo imaging, Eye models

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Proceedings Article | 18 March 2018 Paper

Investigation of the effect of directional (off-axis) illumination on the reflectivity of retina layers in mice using swept-source optical coherence tomography

Ratheesh Meleppat, Myeong Jin Ju, Pengfei Zhang, Yifan Jian, Suman Manna, Daniel Wahl, Marinko Sarunic, Edward Pugh, Robert Zawadzki

Proceedings Volume 10474, 104742B (2018) https://doi.org/10.1117/12.2288739

KEYWORDS: Reflectivity, Optical coherence tomography, Retina, Retinal scanning, Visibility, Tissue optics, Backscatter, Imaging systems

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Proceedings Article | 14 March 2018 Presentation

Image-based adaptive optics compared to wavefront sensing methods for retinal imaging (Conference Presentation)

Daniel Wahl, Pengfei Zhang, Yifan Jian, Stefano Bonora, Robert Zawadzki, Marinko Sarunic

Proceedings Volume 10502, 105020G (2018) https://doi.org/10.1117/12.2291244

KEYWORDS: Adaptive optics, Wavefront sensors, Retinal scanning, Retina, In vivo imaging, Wavefronts, Image sensors, Sensors, Luminescence, Scanning laser ophthalmoscopy

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SPIE Journal Paper | 1 November 2017 Open Access

Multiscale sensorless adaptive optics OCT angiography system for in vivo human retinal imaging

Myeong Jin Ju, Morgan Heisler, Daniel Wahl, Yifan Jian, Marinko Sarunic

JBO, Vol. 22, Issue 12, 121703, (November 2017) https://doi.org/10.1117/12.10.1117/1.JBO.22.12.121703

KEYWORDS: Optical coherence tomography, Imaging systems, Adaptive optics, Retinal scanning, Cornea, Sensors, Angiography, Image resolution, Capillaries, Eye

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Proceedings Article | 24 April 2017 Presentation

Wavefront sensorless adaptive optics versus sensor-based adaptive optics for in vivo fluorescence retinal imaging (Conference Presentation)

Daniel Wahl, Pengfei Zhang, Yifan Jian, Stefano Bonora, Marinko Sarunic, Robert Zawadzki

Proceedings Volume 10073, 100731G (2017) https://doi.org/10.1117/12.2253368

KEYWORDS: Aberration correction, Adaptive optics, Sensors, In vivo imaging, Luminescence, Retinal scanning, Wavefronts, Retina, Control systems design, Deformable mirrors

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Proceedings Article | 24 April 2017 Presentation

Real time optimization algorithm for wavefront sensorless adaptive optics OCT (Conference Presentation)

Hans R. G. Verstraete, Morgan Heisler, Myeong Jin Ju, Daniel Wahl, Laurens Bliek, Jeroen Kalkman, Stefano Bonora, Marinko Sarunic, Michel Verhaegen, Yifan Jian

Proceedings Volume 10073, 100731B (2017) https://doi.org/10.1117/12.2252732

KEYWORDS: Optical components, Actuators, Optical coherence tomography, Wavefronts, Sensors, Adaptive optics, Optimization (mathematics), Imaging systems, In vivo imaging, Ophthalmology

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Proceedings Article | 19 April 2017 Presentation

Data-based online nonlinear extremum-seeker for wavefront sensorless adaptive optics OCT (Conference Presentation)

Yifan Jian, Hans R. G. Verstraete, Morgan Heisler, Myeong Jin Ju, Daniel Wahl, Laurens Bliek, Jeroen Kalkman, Stefano Bonora, Michel Verhaegen, Marinko Sarunic

Proceedings Volume 10053, 1005327 (2017) https://doi.org/10.1117/12.2253184

KEYWORDS: Nonlinear optics, Adaptive optics, Optical coherence tomography, Wavefronts, Sensors, In vivo imaging, Retinal scanning, Image resolution, Retina, Optimization (mathematics)

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Proceedings Article | 19 April 2017 Presentation

GPU accelerated optical coherence tomography angiography using strip-based registration (Conference Presentation)

Morgan Heisler, Sieun Lee, Zaid Mammo, Yifan Jian, Myeong Jin Ju, Dongkai Miao, Eric Raposo, Daniel Wahl, Andrew Merkur, Eduardo Navajas, Chandrakumar Balaratnasingam, Mirza Faisal Beg, Marinko Sarunic

Proceedings Volume 10053, 1005306 (2017) https://doi.org/10.1117/12.2253588

KEYWORDS: Image processing, Visual analytics, Image registration, Optical coherence tomography, Angiography, Visualization, Image segmentation, Image quality, Vascular diseases, Pathology

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Proceedings Article | 19 April 2017 Presentation

Wavefront sensorless adaptive optics optical coherence tomography for multiphoton retinal imaging (Conference Presentation)

Daniel Wahl, Michelle Cua, Sujin Lee, Stefano Bonora, Robert Zawadzki, Yifan Jian, Marinko Sarunic

Proceedings Volume 10053, 1005302 (2017) https://doi.org/10.1117/12.2250218

KEYWORDS: Adaptive optics optical coherence tomography, Optical coherence tomography, Retina, Retinal scanning, Luminescence, In vivo imaging, Aberration correction, Sensors, Image quality, Wavefronts

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Proceedings Article | 21 February 2017 Presentation + Paper

Wavefront control with a multi-actuator adaptive Lens in imaging applications

J. Mocci, M. Cua, S. Lee, Y. Jian, P. Pozzi, M. Quintavalla, C. Trestino, H. Verstraete, D. Wahl, R. Muradore, R. Zawadzki, M. Verhaegen, M. Sarunic, S. Bonora

Proceedings Volume 10073, 1007302 (2017) https://doi.org/10.1117/12.2250016

KEYWORDS: Wavefronts, Microscopy, Optical coherence tomography, Deformable mirrors, Adaptive optics, Sensors, Wavefront sensors, Wavefront aberrations, Actuators, Electrodes, Control systems, Genetic algorithms, Microscopes

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Proceedings Article | 15 March 2016 Presentation + Paper

Wavefront sensorless approaches to adaptive optics for in vivo fluorescence imaging of mouse retina

Daniel Wahl, Stefano Bonora, Oscar Mata, Bengt Haunerland, Robert Zawadzki, Marinko Sarunic, Yifan Jian

Proceedings Volume 9717, 97170A (2016) https://doi.org/10.1117/12.2213572

KEYWORDS: Adaptive optics, In vivo imaging, Retina, Aberration correction, Eye

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Showing 5 of 14 publications

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