The Optical Topography system consists of three parts. The first is the light source, which generates laser beam of 695nm and 830nm through optical fibers. The second is the probe, which directs the modulated laser light onto the examinee's head at the preset position and receives the reflection back from the head. Reflected light is led to the avalanche photodiodes through the fibers. The third is the controller, which converts the optical signals into the electrical ones, analyses the data and then displays the results. It also controls the entire system.
The probe consists of a soft plastic board on which the optical fibers are attached. The picture shown here is a pair of probe gears that is able to measure both hemispheres simultaneously.
