Journal: Journal of Biomedical Optics

Article Title: Optical fiber-based dispersion for spectral discrimination in fluorescence lifetime imaging systems

doi: 10.1117/1.JBO.25.1.014506

Figure Lengend Snippet: List of optical fibers used in the spectral lifetime experiment. Some data are unavailable from the manufacturers. Values in italic are measured by authors.

Article Snippet: The impact of fiber diameter and fiber material on spectral separation was also studied (shown in ) with four types of GRIN fibers: Corning ClearCurve OM4, Corning InfiniCor300 OM1, Newport F-ML-D-C, and Fujikura G.800/1000, with core diameters of 50, 62.5, 100, and 800 μ m , respectively.

Techniques: Transmission Assay

Journal: Journal of Biomedical Optics

Article Title: Optical fiber-based dispersion for spectral discrimination in fluorescence lifetime imaging systems

doi: 10.1117/1.JBO.25.1.014506

Figure Lengend Snippet: (a) Estimated lifetime distribution with fiber dispersion for YG:red bead mixture. The averaged estimated lifetime for YG shifts from 2.2 to 2.1 ns and for red shifts from 2.8 to 3.18 ns. These delays ( − 0.1 ns ) and ( + 0.3 ns ) are an effect of the convolved spectral distribution with the real lifetime distribution of the observed photons. The colored curves are separable because of the fiber spectral dispersion. The green dotted line shows the YG beads and red dotted line shows the red beads with the fiber. The noncolored curves show the beads without fiber. (b) The estimated lifetime images in the same color scheme, with the color scale determined by the range of the estimated lifetime with fiber (2100 to 4500 ps). With the fiber, the dynamic range (thus, the contrast) of the image (b-i) increases compared to the (b-ii) nonfiber case. (c) Calibration curve for temporal delay due to fiber chromatic dispersion with respect to the change in the emission wavelength. For this calibration, second harmonic signal was measured for a series of wavelengths with the 30-m 800 - μ m GRIN fiber and used to create spectral LUT for the images. (d) Spectral images (obtained by mapping shift to spectrum) of the same measurements from (b) shown in the same spectral color scale. With the fiber, the red and YG beads can be visually identified in color, but there is no contrast and no meaningful spectral information is displayed.

Article Snippet: The impact of fiber diameter and fiber material on spectral separation was also studied (shown in ) with four types of GRIN fibers: Corning ClearCurve OM4, Corning InfiniCor300 OM1, Newport F-ML-D-C, and Fujikura G.800/1000, with core diameters of 50, 62.5, 100, and 800 μ m , respectively.

Techniques: Dispersion

Journal: Journal of Biomedical Optics

Article Title: Optical fiber-based dispersion for spectral discrimination in fluorescence lifetime imaging systems

doi: 10.1117/1.JBO.25.1.014506

Figure Lengend Snippet: Spectral separation (represented by relative temporal shift in ns between two bead groups) demonstrated with step-index and GRIN fibers of various lengths. The fibers used are (a) Thorlabs 400 / 425 - μ m step-index fibers and (b) Corning InfiniCor300 OM1 62.5 / 125 - μ m GRIN fibers of 10, 30, and 50 m in length, respectively (refer to Table 1 ). The fiber length (in meters) and fiber diameter (in μ m ) are marked below each image. The sample is a mixture of 10 - μ m YG (emission 486 nm) and 2 - μ m red fluorescent microspheres (emission 554 nm) excited at 490 nm. (c) and (d) The difference in averaged shift between two bead groups for 400 - μ m step-index fibers and 62.5 - μ m GRIN fibers of three lengths. Images were taken with a 20 × air objective ( NA = 0.75 ). The acquisition time was 60 s for all the images in this paper unless otherwise specified.

Article Snippet: The impact of fiber diameter and fiber material on spectral separation was also studied (shown in ) with four types of GRIN fibers: Corning ClearCurve OM4, Corning InfiniCor300 OM1, Newport F-ML-D-C, and Fujikura G.800/1000, with core diameters of 50, 62.5, 100, and 800 μ m , respectively.

Techniques:

Journal: Journal of Biomedical Optics

Article Title: Optical fiber-based dispersion for spectral discrimination in fluorescence lifetime imaging systems

doi: 10.1117/1.JBO.25.1.014506

Figure Lengend Snippet: Zemax simulation of the fiber coupling in the proposed system to study the theoretical limits of the transmission. The combination of f = 50 mm (diameter of 1 in.) and f = 20 mm (diameter of 1/2 in.) plano-convex lenses is used to reduce the beam diameter of fluorescent emission light, which is in turn focused to the tip of the fiber which is mounted to Thorlabs CFC-11x-A collimator by a built-in f = 11 mm aspheric lens ( NA = 0.3 ). At ± 0.85 - deg input scan angle to f = 50 mm lens, the FOV at the tip of the fiber is 800 μ m , matching the core diameter of Fujikura G.800/1000 GRIN fiber. Different colors represent different scan angles.

Article Snippet: The impact of fiber diameter and fiber material on spectral separation was also studied (shown in ) with four types of GRIN fibers: Corning ClearCurve OM4, Corning InfiniCor300 OM1, Newport F-ML-D-C, and Fujikura G.800/1000, with core diameters of 50, 62.5, 100, and 800 μ m , respectively.

Techniques: Transmission Assay

Journal: Journal of Biomedical Optics

Article Title: Optical fiber-based dispersion for spectral discrimination in fluorescence lifetime imaging systems

doi: 10.1117/1.JBO.25.1.014506

Figure Lengend Snippet: Spectral separation (translated to relative temporal shift in ns) demonstrated with 30-m-long GRIN fibers of various core diameters and material compositions. (a-i) Corning ClearCurve OM4, (a-ii) Corning InfiniCor300 OM1, (a-iii) Newport F-ML-D-C, and (a-iv) Fujikura G.800/1000. (a) Shift images are plotted with the same look up tables (LUTs) for all the fibers. The sample is a mixture of 10 - μ m YG (emission 486 nm) and 2 - μ m red fluorescent microspheres (emission 554 nm) excited at 490 nm. (b) The difference in shift between two bead groups for different fibers. Images were taken with a Nikon Plan Apo 20 × / 0.75 objective. In this experiment, 8x zoom was used to achieve the same FOV for all the fibers for a fair comparison.

Article Snippet: The impact of fiber diameter and fiber material on spectral separation was also studied (shown in ) with four types of GRIN fibers: Corning ClearCurve OM4, Corning InfiniCor300 OM1, Newport F-ML-D-C, and Fujikura G.800/1000, with core diameters of 50, 62.5, 100, and 800 μ m , respectively.

Techniques: Comparison

Journal: PLoS ONE

Article Title: Multiphoton Fluorescence Microscopy with GRIN Objective Aberration Correction by Low Order Adaptive Optics

doi: 10.1371/journal.pone.0022321

Figure Lengend Snippet: A standard two–photon fluorescence microscope was modified by insertion of an AO module, a PSF calibration system and a GRIN fiber objective (grey boxes).

Article Snippet: The naked GRIN fiber was purchased from GRINTECH Gmbh.

Techniques: Fluorescence, Microscopy, Modification

Journal: PLoS ONE

Article Title: Multiphoton Fluorescence Microscopy with GRIN Objective Aberration Correction by Low Order Adaptive Optics

doi: 10.1371/journal.pone.0022321

Figure Lengend Snippet: Top: the objective was assembles using a commercial aspheric lens coupled to the GRIN fiber and embodied in an anodized aluminum mount with a standard microscope collar. Bottom: Zemax spot diagrams for the Deformable Mirror plus GRIN objective combination in water; left box, the nominal on–axis Airy disk is about 2 µm; center box: beam distortion at 80 µm from center; right box: simulated correction performed by the EMM.

Article Snippet: The naked GRIN fiber was purchased from GRINTECH Gmbh.

Techniques: Microscopy