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S Damaskinos

Publications and source records attributed to S Damaskinos.

4 recordsLinked to original sources

Inexpensive, high-quality optical relay for use in confocal scanning beam imaging

An inexpensive, high optical-quality relay lens made up of two eyepieces arranged in an afocal assembly for use in confocal scanning laser imaging is described. In the past we have used relays, within our confocal microscopes, made up of achromats with long focal lengths (> or = 10 cm), which take up large optical tracks and suffer from significant amounts of astigmatism and curvature of field. We quantify aberrations associated with achromat and eyepiece relays using CODE V optical design and analysis software. The eyepiece relay is found to be more compact, better corrected, and not significantly more expensive than its achromat counterpart. In addition to being used to interconnect two scanning mirrors optically as well as scanning mirrors with microscope objectives, it can form part of the optics in a confocal scanning laser MACROscope-Microscope system (Biomedical Photometrics, Inc., Waterloo, Ontario, Canada). Due to design constraints, the MACROscope-Microscope system cannot incorporate a conventional wide-field microscope into its structure such as is done in most commercial confocal microscopes. The eyepiece relay is used as a stand-alone, compact optical link between the scanning mirrors and the microscope objective. This consequently makes the MACROscope-Microscope system more compact and easier to commercialize.

Journal Article↗

A scanning beam time-resolved imaging system for fingerprint detection.

A highly sensitive confocal scanning-beam system for time-resolved imaging of fingerprints is described. Time-resolved imaging is a relatively new forensic procedure for the detection and imaging of latent fingerprints on fluorescent substrates such as paper, cardboard, and fluorescent paint. Ordinary fluorescent imaging of latent fingerprints on these surfaces results in poor contrast. Instead, the specimens are treated with a phosphorescent dye that preferentially adheres to the fingerprint which allows time-resolved discrimination between the fingerprint phosphorescence and the background fluorescence. Time resolved images are obtained by synchronizing the digital sampling of the specimen luminescence with the on-off cycle of the chopped illumination beam. The merit of this technique is illustrated with high contrast images of fingerprints obtained from the fluorescent painted surface of a Coke can.

Coloring Agents↗

Imaging electrophoretic gels with a scanning beam laser macroscope.

A scanning beam laser macroscope has been developed which scans an area of 7.5 x 7.5 cm in 5 s. This new imaging system is examined as a potential tool for scanning electrophoretic gels. A specially-designed telecentric, f* theta laser scan lens is used in the instrument to achieve a linear scan and a flat focal plane. The laser scan lens focuses the incoming beam from a laser to a 10 microns spot inside the gel. A raster scan is performed across the gel and the signal is detected with a photomultiplier, forming a 512 x 512 digital image stored as a computer file. Silver-stained protein polyacrylamide gels have been imaged in transmission and double-transmission, while DNA agarose gels (stained with ethidium bromide) have been imaged in fluorescence with better than 25 pg sensitivity. The macroscope has the advantage that it is not tied to the electrophoresis system as are end-of-line scanners, and the scan is rapid, so that several gels can be scanned in a very short time.

Animals↗