Midwest Free Electron Laser Program
Abstract
Subablative effects of pulsed Nd:YAG laser (1064nm) on the transmission of neural impulses in spinal cord dorsal white matter, spinal dorsal roots, and peripheral nerve in anesthetized rat were compared. The results to date indicate that long lasting impairment in both spinal synaptic transmission and small fiber input may be mediated by laser irradiation. Nonlinear crystal mixing techniques have been employed to generate tunable infrared laser radiation in the 5-7 micron region with duration of 20 picoseconds. Characterization techniques of laser beams from the infrared to the ultraviolet were established for probing energy absorption and relaxation processes. Molecular studies of laser energy absorption and relaxation with relevance to fundamental studies in medicine and neuroscience were initiated. New methods to probe biological tissue with the FEL by spectroscopic or imaging techniques were developed. New fabrication techniques of the whispering-gallery waveguide have been employed to obtain high quality specimens. Needle-like hollow metallic IR waveguides have been fabricated with lengths up to 30cm. A diffuse optics spectrophotometer has been constructed that measures the optical constants of light scattering layers from 450 to 1350nm. Data analysis based on the diffusion approximation leads to values of the microscopic optical constants. The instrument has been employed in the measurements of endogeneous and exogeneous chromophore absorptions in tissue models in vitro plant and animal tissues.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 31, 1988
- Accession Number
- ADA198243
Entities
People
- K. G. Spears
- L. J. Cerullo
- M. E. Marhic
- M. Epstein
- W. Z. Rymer