METHOD AND APPARATUS FOR FREQUENCY ENCODED ULTRASOUND-MODULATED OPTICAL TOMOGRAPHY OF DENSE TURBID MEDIA

An apparatus (10) for frequency encoded ultrasound modulated optical tomography is provided. A function generator (12) produces a frequency sweep signal which is applied to an ultrasonic transducer (20). The ultrasonic transducer (20) produces ultrasonic wave (25) in a turbid medium (21). Coherent light from a laser (22) is passed through turbid medium (21) where it is modulated by the ultrasonic wave (25). A photomultiplier tube (24) detects the light which passes through the turbid medium (21). The signal from the photomultiplier tube (24) is fed to an oscilloscope (30) and then to a computer (32) where differences in light intensity at different frequencies can determine the location of objects in the turbid medium (21).