Extended Range Optical Imaging System for use in Turbid Media

A method for optically imaging a target in a turbid medium, comprising:

• generating a beam of coherent light;
• modulating the intensity of the beam of coherent light by an electro-optic modulator driven by a radio frequency modulation signal;
• encoding the radio frequency modulation signal with scan information;
• directing the modulated beam of coherent light from a first location through the turbid medium toward the target;
• scanning the modulated beam of coherent light in a predetermined pattern over the target according to the scan information, to illuminate the target and cause modulated light to be reflected therefrom;
• detecting the modulated light reflected from the target at a second location in the turbid medium to derive an output signal that varies in proportion to the modulated reflected light;
• demodulating the output signal to derive information comprising the scan information;
• and
• constructing an image from the output signal and the scan information so derived.

An apparatus to optically image a target in a turbid medium, comprising:

• a source of coherent electromagnetic energy that emits a beam that is transmissible in a turbid medium;
• a modulator to modulate the beam of electromagnetic energy with information comprising scan information;
• a scanner to direct the beam through the turbid medium and to scan the beam over the target;
• a detector to detect the electromagnetic energy reflected from the target and to output a signal;
• a demodulator to demodulate the output signal from the detector and to derive information comprising the scan information;
• an analog to digital converter to digitize the demodulated output signal from the detector;
• and
• an image processor to convert the digitized signal from the analog to digital converter to a grayscale image.