Apparatus and method for acquiring time-resolved measurements utilizing direct digitization of the temporal point spread function of the detected light

An apparatus for acquiring time-resolved measurements from a sample from optical scanning, comprising:

• a) pulsed laser light directed to a sample;
• b) a first detector disposed to detect the light after exiting from the sample, the detected light being in the form of a first temporal point spread function (TPSF);
• c) a first amplifier to amplify the first TPSF;
• d) a first analog-to-digital converted (ADC) to directly digitize the first TPSF;
• e) a first buffer connected to said first ADC;
• f) a time-pickoff detector to initiate said first ADC to digitize the first TPSF;
• g) means for generating a clock burst, said means being initiated by said time-pickoff detector to provide conversion timing to said first ADC;
• and
• h) a computer programmed to fit the digitized first TPSF to a theoretical curve to extract its amplitude, and attenuation and scattering coefficients.

A method for acquiring time-resolved measurements from a sample from optical scanning, comprising:

• a) directing a pulse of light onto a surface of the sample;
• b) detecting the light that exits from the sample in the form of a temporal point spread function (TPSF);
• c) directly digitizing the TPSF;
• and
• d) extracting a transport scattering coefficient and a absorption coefficient from the digitized TPSF.