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Laser-stimulated fluorescence in paleontology.

Kaye TG, Falk AR, Pittman M, Sereno PC, Martin LD, Burnham DA, Gong E, Xu X, Wang Y - PLoS ONE (2015)

Bottom Line: A laser's ability to concentrate very high flux rates both at the macroscopic and microscopic levels results in specimens fluorescing in ways a standard UV bulb cannot induce.The recent cost reductions in medium-power short wavelength lasers and use of standard photographic filters has now made this technique widely accessible to researchers.This represents a highly cost-effective way to address paleontology's preparatory bottleneck.

View Article: PubMed Central - PubMed

Affiliation: Burke Museum of Natural History and Culture, Seattle, Washington, United States of America.

ABSTRACT
Fluorescence using ultraviolet (UV) light has seen increased use as a tool in paleontology over the last decade. Laser-stimulated fluorescence (LSF) is a next generation technique that is emerging as a way to fluoresce paleontological specimens that remain dark under typical UV. A laser's ability to concentrate very high flux rates both at the macroscopic and microscopic levels results in specimens fluorescing in ways a standard UV bulb cannot induce. Presented here are five paleontological case histories that illustrate the technique across a broad range of specimens and scales. Novel uses such as back-lighting opaque specimens to reveal detail and detection of specimens completely obscured by matrix are highlighted in these examples. The recent cost reductions in medium-power short wavelength lasers and use of standard photographic filters has now made this technique widely accessible to researchers. This technology has the potential to automate multiple aspects of paleontology, including preparation and sorting of microfossils. This represents a highly cost-effective way to address paleontology's preparatory bottleneck.

No MeSH data available.


Related in: MedlinePlus

Laser mounted on a stereo microscope.A 532 nm green laser mounted to the side of a stereo microscope. The blocking filter is mounted in front of the objective lens. No diffuser is used here for maximum effect with a smaller spot.
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pone.0125923.g001: Laser mounted on a stereo microscope.A 532 nm green laser mounted to the side of a stereo microscope. The blocking filter is mounted in front of the objective lens. No diffuser is used here for maximum effect with a smaller spot.

Mentions: A laboratory setup for table-top-sized specimens would typically hold the laser on a fixed mount (Fig 1). The laser itself emits a collimated beam, which results in only a small dot of illumination. This beam can be used as is for maximum flux or be expanded using a diffuser (ARF used a 20-degree diffraction diffuser from Thorlabs). The smaller the angle of the diffuser, the better—i.e. 20 degrees would be better than 50 degrees, as it restricts the beam to a narrower angle and results in a brighter and smaller area of illumination, even if the laser is placed further away from the specimen. The laser should illuminate as much of the specimen as possible, and the diffuser’s cone angle changes the area covered by the laser depending on the laser-to-specimen distance.


Laser-stimulated fluorescence in paleontology.

Kaye TG, Falk AR, Pittman M, Sereno PC, Martin LD, Burnham DA, Gong E, Xu X, Wang Y - PLoS ONE (2015)

Laser mounted on a stereo microscope.A 532 nm green laser mounted to the side of a stereo microscope. The blocking filter is mounted in front of the objective lens. No diffuser is used here for maximum effect with a smaller spot.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4446324&req=5

pone.0125923.g001: Laser mounted on a stereo microscope.A 532 nm green laser mounted to the side of a stereo microscope. The blocking filter is mounted in front of the objective lens. No diffuser is used here for maximum effect with a smaller spot.
Mentions: A laboratory setup for table-top-sized specimens would typically hold the laser on a fixed mount (Fig 1). The laser itself emits a collimated beam, which results in only a small dot of illumination. This beam can be used as is for maximum flux or be expanded using a diffuser (ARF used a 20-degree diffraction diffuser from Thorlabs). The smaller the angle of the diffuser, the better—i.e. 20 degrees would be better than 50 degrees, as it restricts the beam to a narrower angle and results in a brighter and smaller area of illumination, even if the laser is placed further away from the specimen. The laser should illuminate as much of the specimen as possible, and the diffuser’s cone angle changes the area covered by the laser depending on the laser-to-specimen distance.

Bottom Line: A laser's ability to concentrate very high flux rates both at the macroscopic and microscopic levels results in specimens fluorescing in ways a standard UV bulb cannot induce.The recent cost reductions in medium-power short wavelength lasers and use of standard photographic filters has now made this technique widely accessible to researchers.This represents a highly cost-effective way to address paleontology's preparatory bottleneck.

View Article: PubMed Central - PubMed

Affiliation: Burke Museum of Natural History and Culture, Seattle, Washington, United States of America.

ABSTRACT
Fluorescence using ultraviolet (UV) light has seen increased use as a tool in paleontology over the last decade. Laser-stimulated fluorescence (LSF) is a next generation technique that is emerging as a way to fluoresce paleontological specimens that remain dark under typical UV. A laser's ability to concentrate very high flux rates both at the macroscopic and microscopic levels results in specimens fluorescing in ways a standard UV bulb cannot induce. Presented here are five paleontological case histories that illustrate the technique across a broad range of specimens and scales. Novel uses such as back-lighting opaque specimens to reveal detail and detection of specimens completely obscured by matrix are highlighted in these examples. The recent cost reductions in medium-power short wavelength lasers and use of standard photographic filters has now made this technique widely accessible to researchers. This technology has the potential to automate multiple aspects of paleontology, including preparation and sorting of microfossils. This represents a highly cost-effective way to address paleontology's preparatory bottleneck.

No MeSH data available.


Related in: MedlinePlus