Front/back tracking InGaAsP diode laser transmitter modules

Variations in the detected power for movement of a single-mode and a multimode fiber in front of various 1.3- mu m InGaAsP diode lasers are measured and compared to the signal obtained from the back-facet monitor. A model to explain the nonlinear relationship between the detected front and back-facet powers is given. This work has application in the design and understanding of stable light sources, biasing of transmitter modules, the fiber attach process, and the interpretation of tests which check the integrity of the fiber attachment.<>