Optical imaging through highly scattering media by use of heterodyne detection in the 13-μm wavelength region

Optical imaging through highly scattering media was studied in the 1.3-microm wavelength region by use of a continuous-wave Nd:YAG laser and an optical heterodyne detection technique. We measured and compared the extinction coefficients of the fat emulsion Intralipid-10% at 0.80, 1.064, and 1.319 microm and demonstrated that the low scattering at 1.319 microm will permit optical imaging through highly scattering media, which otherwise may not be achieved. A possible use of water absorption at 1.319 microm to image the interior structure of biological tissues is also presented and discussed.