Abstract: Microdistances may be measured between a pair of objects such as a laser diode and an optical fiber end extending toward the diode. One orients the ends of a light emitting fiber and a light sensing fiber for the light sensing fiber to sense light from the emitting fiber. One moves the fibers in such relation until the laser diode or other object passes between the emitting and sensing fibers to occlude light passing between them. One then advances the emitting and sensing fibers toward the optical fiber end until light passing between the emitting and sensing fibers increases to a predetermined value, then noting the position of the emitting and sensing fibers. Then, one further advances the emitting and sensing fibers until the second object passes between the emitting and sensing fibers to occlude light passing between them. One then again notes the position of the emitting and sensing fibers.