Attenuation coefficient μt of blood measured by a modified direct method

A modified direct method for subtracting axial scattered light was put forward, that is, when the collimated transmission measured, the axial scattered light was deducted by a small angle scattered light with the same beam size. And μ t values of two different samples of human whole blood were measured at laser wavelengths of 488,632.8 and 1341.4nm, respectively. It showed that μ t was different for the same blood sample at different wavelength and for different blood sample at the same wavelength.