A5015870275- Optical Coherence Tomography Applications
- Advanced Fluorescence Microscopy Techniques
- Photoacoustic and Ultrasonic Imaging
- Orbital Angular Momentum in Optics
- Image Processing Techniques and Applications
- Thermography and Photoacoustic Techniques
- Retinal and Macular Surgery
- Adaptive optics and wavefront sensing
- Near-Field Optical Microscopy
- Laser Material Processing Techniques
- Optical measurement and interference techniques
- Surface Roughness and Optical Measurements
- Integrated Circuits and Semiconductor Failure Analysis
- Digital Holography and Microscopy
- Calibration and Measurement Techniques
- Glaucoma and retinal disorders
- Cell Image Analysis Techniques
- Optical Polarization and Ellipsometry
- Coronary Interventions and Diagnostics
- Advanced Surface Polishing Techniques
- Thermal properties of materials
- Gold and Silver Nanoparticles Synthesis and Applications
- Infrared Target Detection Methodologies
- Optical Coatings and Gratings
- Photonic and Optical Devices
Korea Basic Science Institute
2014-2024
Hanbat National University
2023
University of Rochester
2009-2014
Instituto de Óptica "Daza de Valdés"
2013
University of Central Florida
2007-2009
Photonics (United States)
2007-2008
Endoscopic imaging in tubular structures, such as the tracheobronchial tree, could benefit from optics with an extended depth of focus (DOF) to accommodate varying sizes structures across patients and along tree within same patient. Yet DOF needs be accomplished without sacrificing resolution while maintaining sufficient sensitivity speed imaging. In this Letter, we report on measured achieved a custom-made micro-optic axicon lens designed theoretically achieve 8 mm DOF. A invariant ~8 μm is...
We report an optical design for a low-cost optics, broadband, astigmatism-corrected practical spectrometer. An off-the-shelf cylindrical lens is used to remove astigmatism over the full bandwidth. Results show that better than 0.1 nm spectral resolution and more 50% throughput were achieved bandwidth of 400 centered at 800 nm.
We recently reported on an Optical Coherence Microscopy technique, whose innovation intrinsically builds a - 2 microm invariant lateral resolution by design throughout mm cubic full-field of view liquid-lens-based dynamic focusing optical probe [Murali et al., Optics Letters 34, 145-147, 2009]. shall report in this paper the image acquisition enabled when combined with automatic data fusion method developed and described here to produce in-focus high imaging depth sample. An African frog...
We analyze the three most common profiles of scanning functions for galvanometer-based scanners (GSs): sawtooth, triangular and sinusoidal functions. They are determined experimentally with regard to scan parameters input signal (i.e., frequency amplitude). study differences output function GS measured as positional error oscillatory mirror from ideal given by device. The limits in achieving different types terms duty cycle linearity possible range parameters. Of particular importance...
An optical coherence tomography (OCT) for high axial resolution corneal imaging is presented. The system uses 375 nm bandwidth (625 to 1000 nm) from a broadband supercontinuum light source. was developed in free space minimize image quality degradation due dispersion. A custom-designed spectrometer based on Czerny Turner configuration implemented achieve an depth of 1 mm. Experimentally measured 1.1 μm tissue and had good agreement with the theoretically calculated envelope spectral...
Gradient Refractive INdex (GRIN) optical components have historically fallen short of theoretical expectations. A recent breakthrough is the manufacturing nanolayered spherical GRIN (S-GRIN) polymer elements, where construction method yields refractive index gradients that exceed 0.08. Here we report on application coherence tomography (OCT), including micron-class axial and lateral resolution advances, as effective, innovative methods for performing nondestructive diagnostic metrology...
We investigate morphological differences in three-dimensional (3-D) images with cellular resolution between nonmelanoma skin cancer and normal using Gabor domain optical coherence microscopy. As a result, we show for the first time of 3-D features differentiating cancerous from skin. In addition, vivo volumetric different anatomic locations are shown compared.
The optical aberrations induced by imaging through skin can be predicted using formulas for Seidel of a plane-parallel plate. Knowledge these helps to guide the choice numerical aperture (NA) optics we use in an implementation Gabor domain coherence microscopy (GD-OCM), where focus is only aberration adjustment made depth. On this basis, custom-designed, liquid-lens enabled dynamic focusing microscope operating at 0.2 NA analyzed and validated experimentally. As part analysis, show that full...
In this Letter, we report for the first time (to our knowledge) in-vivo volumetric optical coherence microscopy images of skin epidermal cells. We achieved micrometer-class resolution, 2 μm laterally and axially, with an acquisition speed 23 K A-scans/s over 90 dB sensitivity to a depth 1 mm by employing custom, liquid-lens-based, dynamic-focusing objective, broadband light source, astigmatism-corrected Czerny-Turner spectrometer high-speed complementary metal-oxide-semiconductor camera.
In laser-plasma interactions (LPI), the laser beam mode is a critical parameter when trying to explore new physical phenomena. Of various spatial modes, Laguerre-Gaussian (LG) with vortex phase has attracted considerable attention due its unique features, including ability carry an orbital angular momentum. Due this, it been actively applied LPI, which mainly utilize ultrashort intense pulses. However, existing transmissive phase-manipulating optical elements have several limitations in LPI...
It has been shown that frequency domain optical coherence tomography (FD-OCT) systems achieve higher sensitivities compared to time (OCT) systems. However, the obscure object structure due mirror image generated by Fourier transform is one of remaining issues in FD-OCT. We designed and developed what we believe be a novel full range FD-OCT system refer as dual detection (DD-FDOCT) enables instantaneous retrieval quadrature components complex interferometric signal. The DD-FDOCT imaging...
Gabor-domain optical coherence microscopy (GD-OCM) is a volumetric high-resolution technique capable of acquiring three-dimensional (3-D) skin images with histological resolution. Real-time image processing needed to enable GD-OCM imaging in clinical setting. We present parallelized and scalable multi-graphics unit (GPU) computing framework for real-time processing. A control mechanism was developed individually assign computation tasks each the GPUs. For GPU, optimal number amplitude-scans...
The optical system design of a dynamic focus endoscopic probe for coherence tomography is reported. capability based on liquid lens technology that provides variable by changing its curvatures in response to an electric field variation. effects cylindrical exit window present, practice, catheter were accounted for. Degradation image quality caused this was corrected get diffraction limited imaging performance. As result, the dynamically focusing with lateral resolution ranging from 4 6 mum...
Most of full-range techniques for Frequency Domain Optical Coherence Tomography (FD-OCT) reported to date utilize the phase relation between consecutive axial lines reconstruct a complex interference signal and hence may exhibit degradation in either mirror image suppression performance or detectable velocity dynamic range both when monitoring moving sample such as flow activity. We have previously technique removal by simultaneous detection quadrature components spectral called...
Live-cell monitoring involves long-term observation and analysis of living cells in tissue cultures, which develop or tissues an artificial environment are essential for engineering. Fluorescence microscopy (FM) is widely used as a tool owing to its powerful ability visualize protein distribution within tissues, thereby providing information on their functions biological processes. To reduce the photobleaching effect, major limiting factor FM, FM generally combined with other imaging...
The statistical ensemble of a fluctuating, statistically-stationary electromagnetic light beam is presented in terms 2 × matrix, so-called coherency matrix. method to determine such matrix for quasi-monochromatic has been proposed many years. In this paper, we demonstrate that the needs be only slightly modified elements broadband stochastic beam, if one uses representation wave fields space–frequency domain. implementation demonstrated, and measurement validated using well-defined...
In recent years, there has been an ever-growing interest in exploring different optical materials and components to develop compact effective systems. The design fabrication of high-performance optics require nondestructive metrology techniques inspect the samples. We have investigated capability coherence tomography (OCT) nondestructively characterize layered polymeric materials. Using a custom developed Gabor-domain microscopy system centered at 800 nm with 120 full width half maximum...
The Gouy phase anomaly, well established for stigmatic beams, is validated here astigmatic beams. We simulate the predicted anomaly near foci using a beam propagation algorithm integrated within lens design software. then compare computational results with experimental data acquired modified Mertz-Sagnac interferometer. Both in simulation and experiment, show that π/2-phase change occurs as passes through each of foci, experimentally validating derived recent paper by Visser Wolf [Opt....
A variable focus microscope without moving parts for axial focusing within the sample in two-photon microscopy can provide a faster, more robust, and cost-effective solution to 3D imaging at high resolution. custom dynamic objective was recently developed that incorporates liquid lens optical design of microscope. In this paper, we investigate use embedded an aberration-corrected z-dimension scanning resolved microscopy. Results show achieve speed 50 frames per sec arbitrary plane space,...
Plasmonic photothermal therapy (PPTT) using gold nanoparticles (AuNPs) has shown great potential for use in selective tumor treatment, because the AuNPs can generate destructive heat preferentially upon irradiation. However, PPTT not been added to practice, owing insufficient heating methods and tissue temperature measurement techniques, leading unreliable inaccurate treatments. Because properties of vary with laser power, particle optical density, depth, accurate prediction generation is...
In this paper, we present the design of a 0.2 NA microscope objective operating across 120nm broadband spectral range that requires only two doublets and an embedded liquid lens to achieve 3 μm invariant lateral resolution throughout large 8 cubic millimeter imaging sample. Achieving comes with some sacrifice in speed, yet approach proposed, high speed vivo is maintained up for 2x2 mm sample size. Thus, anticipation ultimately aim 0.5 1 μm, are investigating possibility further gain using...
Wavelength-tunable spiral-phase-contrast (SPC) imaging was experimentally accomplished in the visible wavelengths spanning a broad bandwidth of ∼200 nm based on single off-axis spiral phase mirror (OSPM). By rotation an OSPM, which designed with integer orbital angular momentum (OAM) l = 1 at wavelength 561 and incidence angle 45°, high-quality SPC obtained different wavelengths. For comparison wavelength-tunable using plate (manufactured to generate OAM nm) performed three (473, 561, 660...
Optical Coherence Microscopy (OCM) is an emerging technology capable of depth sectioning biological tissue at the micrometer scale. In this paper, we propose a developing call Gabor Domain (GD-OCM), whose innovation two folds: (1) A high lateral resolution optical design dynamic-focusing probe with no moving parts, which provides invariant currently 3 μm across 2mm full-field view and imaging by design; (2) An acquisition scheme (using probe) that performing automatic data fusion to...
We report parallel spectral-domain optical coherence tomography (OCT) at 500 000 A-scan/s. This is the highest-speed (SD) OCT system using a single line camera. Spectrally encoded line-field scanning proposed to increase imaging speed in SD-OCT effectively, and tradeoff between speed, depth range, sensitivity demonstrated. show that three modes of 125k, 250k, 500k A-scan/s can be simply switched according sample imaged considering range sensitivity. To demonstrate biological performance...