A two fiber interferometric approach to measuring the ocular pulse

A two-fiber approach to an ocular pulse sensing interferometer is presented. The theory of interferometry is reviewed, and the two-fiber interferometer system used is described. An HeNe laser produced a monochromatic and coherent beam, which was divided into two components by a beam splitter. One beam traveled to the reference mirror and was then reflected down through the beam splitter to another beam splitter, where it recombined with the returning target beam. The target beam went through the first beam splitter and entered the first fiber. The first GRIN (graded index) lens produced a collimated beam which reflected from the target (a model of the eye) and was then refocused into a second fiber. The target beam was emitted from the second GRIN lens and combined with the source beam with the aid of the second beam splitter. The combined beam was then detected by the photodetector and analyzed