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Jannick P. Rolland
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Mentioned In 69 Articles
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Point-cloud noncontact metrology of freeform optical surfaces
Full Article Figures (16) Tables (2) Equations (14) References (52) Cited By (0) Back to Top Get PDF Abstract In this paper, we demonstrate the development of a point-cloud metrology method for the noncontact, high resolution, high precision testing of freeform surfaces. The method leverages swept source optical coherence tomography together with a common-path setup in the sample arm configured to mitigate the axial jitter caused by scanning and environmental ...Read Full Article -
Viscoelastic characterization of dispersive media by inversion of a general wave propagation model in optical coherence elastography
Determining the mechanical properties of tissue such as elasticity and viscosity is fundamental for better understanding and assessment of pathological and physiological processes. Dynamic optical coherence elastography uses shear/surface wave propagation to estimate frequency-dependent wave speed and Youngs modulus. However, for dispersive tissues, the displacement pulse is highly damped and distorted during propagation, diminishing the effectiveness of peak tracking approaches. The majority of methods used to determine mechanical properties ...Read Full Article -
Measurement of the lipid and aqueous layers of a tear film
Systems and methods for determining thickness of lipid and aqueous layers of a tear film in which a spectrum array is generated from optical coherence tomography and input into a statistical estimator, which determines the thickness of the lipid and/or aqueous layers at a nanometer resolution based on the inputted spectrum and other information, such as information about a laser intensity noise, Poisson noise, and dark noise associated with ...Read Full Article -
Comparative study of shear wave-based elastography techniques in optical coherence tomography
We compare five optical coherence elastography techniques able to estimate the shear speed of waves generated by one and two sources of excitation. The first two techniques make use of one piezoelectric actuator in order to produce a continuous shear wave propagation or a tone-burst propagation (TBP) of 400 Hz over a gelatin tissue-mimicking phantom. The remaining techniques utilize a second actuator located on the opposite side of the region ...Read Full Article -
3D wide field-of-view Gabor-domain optical coherence microscopy advancing real-time in-vivo imaging and metrology
Real-time volumetric high-definition wide-field-of-view in-vivo cellular imaging requires micron-scale resolution in 3D. Compactness of the handheld device and distortion-free images with cellular resolution are also critically required for onsite use in clinical applications. By integrating a custom liquid lens-based microscope and a dual-axis MEMS scanner in a compact handheld probe, Gabor-domain optical coherence microscopy (GD-OCM) breaks the lateral resolution limit of optical coherence tomography through depth, overcoming the tradeoff between ...Read Full Article -
Optical Assessment of Soft Contact Lens Edge-Thickness
Purpose: To assess the edge shape of soft contact lenses using Gabor-Domain Optical Coherence Microscopy (GD-OCM) with a 2-m imaging resolution in three dimensions and to generate edge-thickness profiles at different distances from the edge tip of soft contact lenses. Methods: A high-speed custom-designed GD-OCM system was used to produce 3D images of the edge of an experimental soft contact lens (Bausch + Lomb, Rochester, NY) in four different configurations: in ...Read Full Article -
Volumetric rendering and metrology of spherical gradient refractive index lens imaged by angular scan optical coherence tomography system
In this paper, we develop the methodology, including the refraction correction, geometrical thickness correction, coordinate transformation, and layer segmentation algorithms, for 3D rendering and metrology of a layered spherical gradient refractive index (S-GRIN) lens based on the imaging data collected by an angular scan optical coherence tomography (OCT) system. The 3D mapping and rendering enables direct 3D visualization and internal defect inspection of the lens. The metrology provides assessment of ...Read Full Article -
MEMS-based handheld scanning probe with pre-shaped input signals for distortion-free images in Gabor-domain optical coherence microscopy
High-speed scanning in optical coherence tomography (OCT) often comes with either compromises in image quality, the requirement for post-processing of the acquired images, or both. We report on distortion-free OCT volumetric imaging with a dual-axis micro-electro-mechanical system (MEMS)-based handheld imaging probe. In the context of an imaging probe with optics located between the 2D MEMS and the sample, we report in this paper on how pre-shaped open-loop input signals ...Read Full Article -
In vivo thickness dynamics measurement of tear film lipid and aqueous layers with optical coherence tomography and maximum-likelihood estimation
Dry eye disease (DED) is a common ophthalmic condition that is characterized by tear film instability and leads to ocular surface discomfort and visual disturbance. Advancements in the understanding and management of this condition have been limited by our ability to study the tear film secondary to its thin structure and dynamic nature. Here, we report a technique to simultaneously estimate the thickness of both the lipid and aqueous layers ...Read Full Article -
Experimental classification of surface waves in optical coherence elastography
Various types of waves are produced when a harmonic force is applied to a semi-infinite half space elastic medium. In particular, surface waves are perturbations with transverse and longitudinal components of displacement that propagate in the boundary region at the surface of the elastic solid. Shear wave speed estimation is the standard for characterizing elastic properties of tissue in elastography; however, the penetration depth of Optical Coherence Tomography (OCT) is ...Read Full Article -
Spectral fusing Gabor domain optical coherence microscopy
Gabor domain optical coherence microscopy (GD-OCM) is one of many variations of optical coherence tomography (OCT) techniques that aims for invariant high resolution across a 3D field of view by utilizing the ability to dynamically refocus the imaging optics in the sample arm. GD-OCM acquires multiple cross-sectional images at different focus positions of the objective lens, and then fuses them to obtain an invariant high-resolution 3D image of the sample ...Read Full Article -
Crawling wave optical coherence elastography
Elastography is a technique that measures and maps the local elastic property of biological tissues. Aiming for detection of micron-scale inclusions, various optical elastography, especially optical coherence elastography (OCE), techniques have been investigated over the past decade. The challenges of current optical elastography methods include the decrease in elastographic resolution as compared with its parent imaging resolution, the detection sensitivity and accuracy, and the cost of the overall system. Here ...Read Full Article -
Simultaneous estimation of thickness and refractive index of layered gradient refractive index optics using a hybrid confocal-scan swept-source optical coherence tomography system
A hybrid confocal-scan swept-source optical coherence tomography metrology system was conceived for simultaneous measurements of the refractive index and thickness profiles of polymeric layered gradient refractive index (GRIN) optics. An uncertainty analysis predicts the metrology capability of the system and guides the selection of an optimum working numerical aperture. Experimental results on both a monolithic and a GRIN layered sheet are demonstrated to be in close agreement with theoretical predictions ...Read Full Article -
Gabor-domain optical coherence microscopy with integrated dual-axis MEMS scanner for fast 3D imaging and metrology
Fast, robust, nondestructive 3D imaging is needed for characterization of microscopic structures in industrial and clinical applications. A custom micro-electromechanical system (MEMS)-based 2D scanner system was developed to achieve 55 kHz A-scan acquisition in a Gabor-domain optical coherence microscopy (GD-OCM) instrument with a novel multilevel GPU architecture for high-speed imaging. GD-OCM yields high-definition volumetric imaging with dynamic depth of focusing through a bio-inspired liquid lens-based microscope design, which has ...Read Full Article
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About Jannick P. Rolland
Jannick Rolland is the Brian J. Thompson Professor of Optical Engineering and Associate Director of the R.E. Hopkins Center for Optical Design & Engineering, and Professor of Biomedical Engineering at the University of Rochester. Dr. Rolland also runs the Optical Diagnostics and Applications Laboratory (ODALab).
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Quotes
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We leveraged emerging technology that is coming out of cell phones, like liquid lenses, and developed a new way to record the data using a spectrometer and dynamic focusing...A liquid lens is made of water and oil on an electrode. When voltage is applied, the surface of the electrode becomes less hydrophobic...By changing the voltage, you can make things more or less hydrophobic and have the water being repulsed or attracted toward the electrode...The oil-water interface changes and you create bending, the different curvature at the interface" which serves as the lens. Changing the voltage changes the focus.
In Breakthrough 3-D optical imaging possible in vivo -
My hope is that, in the future, this technology could remove significant inconvenience and expense from the process of skin lesion diagnosis...When a patient walks into a clinic with a suspicious mole, for instance, they wouldn't have to have it necessarily surgically cut out of their skin or be forced to have a costly and time-consuming MRI done. Instead, a relatively small, portable device could take an image that will assist in the classification of the lesion right in the doctor's office."
In A New High-Resolution Method for Imaging Below the Skin using a Liquid Lens
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