Phase dispersive tomography

A method for optically measuring biological tissue comprising:

• providing a first wavelength and a second wavelength of light such that the second wavelength is harmonically related to the first wavelength;
• providing a detector system connected to a data processor;
• directing light of the first wavelength and the second wavelength along both a first optical path and a second optical path, the first optical path extending onto the tissue to be measured and the second path undergoing a change in path length;
• detecting light from the tissue and light from the second optical path with the detector system to measure a change in phase of light interacting with the tissue;
• and
• determining a characteristic of the tissue with the data processor using the measured change in phase.

A device for optically measuring a medium comprising:

• a light source that provides a first wavelength and a second wavelength of light such that the second wavelength harmonically related to the first wavelength;
• an optical system that couples light of the first wavelength and the second wavelength along both a first optical path and a second optical path, the first optical path extending onto a medium to be measured and the second path undergoing a change in path length;
• and
• a detector that detects light from the medium and light from the second optical path to measure a change in phase of light interacting with the medium.