Patent ID: 7505135

Claim:
A non-interferometric method for determining the optical temporal response of an optically scattering medium to a short optical pulse excitation, said method comprising the following steps: (a) sending a modulated beam of light from a light source through said medium, wherein said light is comprised of at least some of the spectral frequencies which make up the Fourier transform of said short optical pulse; (c) measuring, for each of said spectral components, the relative amplitude with respect to that of said light source; (c1) measuring, for each of said spectral components, the difference between the modulation phase of said light exiting said medium and the modulation phase of said modulated beam of light entering said medium; (c2) determining, the phase change of the optical field of each of said spectral components with respect to that of said light from said light source entering the medium from the values of the difference between the modulation phase of said light exiting said medium and the modulation phase of said modulated beam of light entering said medium; (d) obtaining the spectral response of said medium from said relative amplitude changes and optical field phase changes; (e) computationally performing an inverse Fourier transform on said spectral response; and (f) obtaining the temporal response of said medium to said emulated short pulse from said inverse Fourier Transform; and (g) repeating step (a) through (f) until said optical temporal response is determined to a pre-determined accuracy, wherein the light sent through said medium in each succeeding cycle is at least partially comprised of different spectral frequencies from those of the preceding cycles; characterized in that the relative amplitude and phase change of each of said spectral components with respect to that of said light source are determined from a single beam of modulated light.