Comparison of the optical transmission properties of pulsed and continuous wave light in biological tissue.

The purpose of this study is to compare the optical transmission of the pulsed gold vapor laser (628 nm) to that of the continuous wave argon-pumped dye laser (630 nm) in a homogenous tissue model. Gluteal muscle was taken from a rabbit, and sections of varying thicknesses were made. The tissue samples were positioned at the aperture of an integrating sphere. The laser light was passed through an optical attenuator, coupled to a 600-microns fiber, and then directed onto the surface of the tissue. Transmitted light was collected by the integrating sphere. Light measurements were made with a radiometer. This procedure was repeated for samples of differing thickness using the gold vapor laser as the light source. The identical procedure was performed using the argon-pumped dye laser. No significant difference was found in percent transmission of light using the gold vapor laser as compared to the argon-pumped dye laser.